Jason Williams on Retül and Bike Fitting Philosophies

We delve into the strengths and potential pitfalls of using comparative data as we discuss the how technology can be used to help fitters make decisions during their fit process.

Jason Williams Retül bike fit

Jason Williams, bike fitter at the Specialized Experience Center in Boulder, is here to discuss Retul bike fit, the methodology of Retül fitting and how the Retul bike fit technology is used to help fitters make decisions during the bike fitting process.

We delve into the strengths and potential pitfalls of using comparative data. We also discuss the current trend of road riders slamming the saddle forward.

If you have comments or questions about this episode, please post them on the Fast Talk Labs forum, there is a page for this episode. Make sure to tag @colby so he sees the post.

Specialized Experience: https://specializedboulder.com

Keith Bontrager K.O.P.S. https://sheldonbrown.com/kops.html

See more from Fast Talk Labs on bike fitting.

Episode Transcript

Intro  00:12

Welcome to the Cycling in Alignment Podcast, an examination of cycling as a practice and dialogue about the integration of sport and right relationship to your life.


Colby Pearce  00:26

Well, hello there listeners, you’ve returned to another episode of Cycling in Alignment, and once again I am grateful for your attention, presence and interest in my work. Today’s interview is with Jason Williams. Jason is a bike fitter, who works at the Specialized Experience Center in Boulder, Colorado. He’s also a Retül fitter, and our conversation revolves around the method of operation of the Retül fit process, and some of Jason’s philosophies on bike fitting hear in. This is part of a series of pods I’ve done with different fitters, and I want to look at the subject from all angles, because the only way to have a complete understanding of a subject is to do a deep dive from all sides. Soup to Nuts, balls to bones. That’s the way I like to think of it. I will say that I’ve known quite a few people who work at Retül over the years, including Todd Carver, one of the i’ll say, original creators of the concept, at least insofar as to bring motion capture to the world of bicycling. That’s how Jason explains it in the pod, he clarified that for us. And while I don’t have an inherent issue with any technology Retül brings to the table, I don’t use it in my fit studio for a variety of reasons. That said, I do think it’s interesting to look at other fitters perspectives and understand the logic of why they made the choices they make. So we’re going to move forward into the conversation and let you hear all the talking points and subtleties, our discussion. Please enjoy the conversation with Jason Williams.


Colby Pearce  02:09

Jason Williams.


Jason Williams  02:12



Colby Pearce  02:13

Thank you for joining me today on our magical podcast adventure, Cycling in Alignment.


Jason Williams  02:18

Great. I’m thrilled to be here.


Colby Pearce  02:20

Yeah. Cool. Short notice, you made it. Tell us about yourself. Tell us about your adventures in life. Where are you from? How did you get into bike fitting?


Jason Williams: Passion for Bikes at a Young Age

Jason Williams  02:30

Well, yeah, I grew up in Maine, started riding bikes as a kid like most of us, but pretty much cut deep into bikes, junior high school and high school, I was just I’ve always been a cyclist, mountain biker, kind of by upbringing and, and riding mountain bikes in the woods of Maine, we used to go out in the swamps and see how deep we could get in the mud and just bury these mountain bikes up to the hubs. It was, you know, probably not great for the bearings, but we had a lot of fun, just, you know, bombing around in the swamps of Maine and mountain biking. So after that got into, you know, I think in college, I started you know, professionally working on bikes, as a mechanic to turn the passion for bikes into, you know, but a side money in college, working on bikes, and pretty much the rest is history. I’ve been professionally in the bike world ever since. So, my entire career has been in the bike world to some degree.


Colby Pearce  03:26

Where did you go to college?


Jason Williams  03:28

In Maine, University of Maine, in Orono.


Jason Williams  03:30



Colby Pearce  03:30

Okay, and do you study?


Jason Williams  03:32

I studied English literature, creative writing, so did some creative writing, as you know, kind of side degree and then English literature as my kind of primary degree.


Colby Pearce  03:42



Jason Williams  03:43



Colby Pearce  03:43



Jason Williams  03:44

It was a great degree, it was super fun to just spend time reading and learning and just getting super into, you know, all these like amazing literary stuff that was really a great degree, really passionate about that stuff, for sure.


Colby Pearce  03:59

But you didn’t end up using that too much in your professional adventures? Or did you?


Jason Williams  04:02

Not really, I mean, it was a really interesting degree, you know, I’ve always kind of felt like, I’m a learner, I love to learn and so like, learning about literature was amazing, and then just turn that into anything going on from there. It’s just, I like to learn about whatever I can.


Colby Pearce  04:19

And this is in the era, you know, before high school mountain biking, which is, of course exploding now. So.


Jason Williams  04:24

Right, I did actually race mountain bikes in the, in the early 90s, Maine actually had a pretty good New England mountain bike scene in the 90s. So did a little bit of mountain bike racing back in those days, on a fully rigid steel mountain bike. Did my first downhill mountain bike race on a fully rigid steel mountain bike. It was great. Yeah, it was a lot of fun.


Colby Pearce  04:46

I had some of those adventures too. I yeah, I did a couple cross country races in Steamboat, Colorado, on a fully rigid bike. But you know, really excited about how it’s going to kill everyone on the climb, because my fork was so much lighter.


Jason Williams  04:59



Colby Pearce  04:59

Until had to go down.


Jason Williams  05:02

I saw my first suspension bike there, you know, with a 70-millimeter travel Marzocchi suspension fork, I was like, “Whoa, it’s amazing.” You look back at that now, and it’s just so, you know, simple but it was, you know, at that time was amazing to see the first suspension bikes come out and it was really cool.


Colby Pearce  05:20

Yeah, that’s funny.


Jason Williams  05:20



Colby Pearce  05:21

Self-respecting cross country we wouldn’t even be caught dead on only 70 mils now.


Jason Williams  05:25

That’s right, exactly.


Colby Pearce  05:26

Yeah. 70 mils is like most gravel bikes have 70 mils, Right?


Jason Williams  05:30



Colby Pearce  05:31

That’s funny. Okay. So then you, you followed your passion for the sport and began to work in a shop as a mechanic? And then how did you actually get your interest kindled in, in where people’s handlebars and whatnot?


How Jason Williams Got Involved in the World of Bike Fitting

Jason Williams  05:44

You know, I think, in the early 2000s, when I, shortly after I moved to Boulder, I was still working as a mechanic kind of a side job, actually tried to get out of the bike world and I did a master’s degree here at CU, in journalism, so a master’s in journalism with an environmental policy certificate. So I specialized in energy policy and environmental journalism, super interesting as well, you know, kind of like the undergrad, like really interesting to learn about all that, but also turned out, I didn’t want to do that for a career either. So, you know, I think about that journalism degree, and again, just wanting to explore and learn about things just and the journalism degree was great, it was a carte blanche to just learn about whatever you’re curious about. And that’s kind of how I’ve always operated, find something you’re curious about, learn about it and become an expert in that, and so journalism was fascinating in that way, but also was working in the bike world on the side. After the grad degree, again, kind of realized it wasn’t my passion to sort of follow that as a career. So kind of turn back to the bike world, and that’s when Ben Serotta came to town for a fit camp, so he did a bike fit training at the Hotel Boulderado, I think 2005. So I joined Ben Serotta for a fit training 2005 kind of really got that started, I had several mentors at the shops, I’d worked with that were fitters, and I was like, “Oh, you know, that’s kind of a mystical thing. What are those guys doing over there?” You know, I was curious about it, but I didn’t really know. I came from the mechanical background, but I also knew I didn’t want to spend the rest of my career working in the trenches, just, you know, up to my elbows in in hub grease, I wanted to explore more and I think ultimately work with the rider, work with, you know, the the people more than just the bike, you know, the bike is fascinating, but I also really liked the interaction with the people and how that interaction plays out working with riders and their bike combined.


Colby Pearce  07:46

And okay, so in 2005, you you studied under Ben Serotta, and then tell me about that experience what, what is involved in that study in that path of learning?


Fundamentals of the Serotta Fit

Jason Williams  08:00

I think the fundamentals of you know, the Serotta fit, I mean, he’s one of the earliest sort of pioneers of bike fit and, you know, simple concepts of, you know, knee over pedal spindle and appropriate knee extension, and, you know, reasonable back angles and things like that, that were just, I’d say fundamentals of bike fit. And then, especially then early on, there was a flexibility evaluation, you know, a physical evaluation to get to know the rider, find out what’s important to that rider, and what’s appropriate for them flexibility and range of motion wise, and then apply that to creating a bike position for that rider. So you know, even those, those early days, it was still very important to understand the riders physical needs, their personal needs, what they’re looking for in the bike, and then design a bike for them. And so the Serotta fit bike, you know, the SICI fit bike was pretty effective tool, I mean, simple by today’s terms, but still really effective at setting, I think appropriate seat height, for and after, you know, reach to the bars, bar height, and, and then using that tool, potentially discussed designing them a custom bike. So Ben Serotta model was, you know, what position is appropriate for the rider? And then let’s figure out how to build a custom Serotta for that rider, and that sort of parlayed into, you know, helping people with their current bikes as well.


Colby Pearce  09:23

Right. So that’s interesting. There’s kind of a couple different paths to deal with a rider when they walk through doors as a fitter, right? Frequently riders have an existing bike, they come in the door, sometimes they don’t know if their bikes the right size, a lot of times they have no idea if it’s been set up right, so as a fitter, you’re, my philosophy and tell me if you agree with this, disagree with this, whatever, is I kind of try to balance the physiology of the rider with the demands of their event, their dream goal or objective.


Jason Williams  09:52



Balancing the Physiology of the Rider with the Demands of Their Event

Colby Pearce  09:53

So someone comes to me and says, “I’m training for unbound gravel.”


Jason Williams  09:56



Colby Pearce  09:58

You know, I’m doing 208 miles or whatever it is, or if their goal is to win the Car to State Time Trial Championships, two very different objectives, so we have to consider that in their bike setup. But we also have to consider the platform from which they’re starting, if Ben only makes custom, fully custom frames, then he’s got this fit bike and you can sort of use any parameter he wants to set up a rider, and then build the frame geometry around that when someone walks through the door with you know a $5,000 investment in their current road bike or gravel bike or whatever their got. You don’t have an unlimited whiteboard to work from necessarily.


Jason Williams  10:38



Colby Pearce  10:38

Sometimes you can only get the bar so low, you can only get the bar so close to them, or so far away or whatever, right? So it just makes me think about challenges we have as a fitter, because sometimes we think that we have this this whiteboard, I guess is what I’m trying to say, but we don’t necessarily. We are working within the constraints of what we can do, with the equipment we’ve got. Another example is cleat position, another common limitation, sometimes you want people’s cleats to be in a different place than the shoe allows, for the pedal allows or both, right?


Jason Williams  11:09

It’s an interesting challenge because in cases when you have that blank slate whiteboard, it’s amazing as far as the possibility, but it’s also daunting when you have all the possibilities in the world, then how do you lay down a point where you say this is perfect for that rider?


Colby Pearce  11:26



Jason Williams  11:27

It’s much easier, in a sense, to say here’s your bike, here’s your problems, here’s your concerns, here’s your event, let’s make improvements to that bike. In a sense that’s easy, because you can say, you don’t like this, and here’s your goals, let’s bring your bike and your position towards your goals and towards your personal needs.


Colby Pearce  11:44



Jason Williams  11:45

And an improvement is a benefit, right? so if you go from not great to better that’s a really positive result. You have somebody that comes in with a blank slate, let’s build a custom bike, then you’re not really improving on something that’s not great, you’re just sort of putting a line in the sand and saying here’s perfect or here’s my version of perfect. That’s a bigger challenge, to say like, what’s perfect for that rider, so it does help when they come in with a bike that they don’t like, so you know you’re not going to duplicate.


Colby Pearce  12:15

You’re moving away from what’s not working.


Jason Williams  12:16

You’re from something. Yeah, I always like to have that benchmark of, here’s your current bike, and even if they love it there’s still some potential for improvement, so let’s measure this bike, let’s talk about how you interact with this bike, let’s talk about your goals, let’s really make sure we examine that bike so we don’t double back on that, and say, okay these are the points you outline that you want to improve on, let’s take your new custom bike in that direction. You know, and perfect is kind of within this window of like adjustability, so when I say here’s your perfect position, I still bank on the fact that some spacers up and down, a stem length longer, shorter, you know we still have to buy into the fact that they may change, you know, their body may change, their goals may change, so you can’t really, I think it would be misguided to lock into a position to say here’s your perfect position forever. I don’t think that’s a reality, I think people have a position that’s really good for them today, and then a year from now we might reevaluate that position.


Colby Pearce  13:19

Yeah, that’s a good point, and I just did an interview with Happy Freedman last week, and he described it more as a, well this is an extension of what you were just saying I think, but he was saying that people don’t really have a perfect position per se, but they have a position range, and the point he used to make to illustrate that is that someone’s height will change, he said up to five centimeters within the course of a day. Because you sleep of course, most people slip horizontally unless you’re a vampire, and so your spine expands, and your fascia relaxes, and your tissues become hydrated assuming you’re actually drinking water, and those types of things, and then you stand up and of course gravity battles you all day, and now I think five centimeters is probably on the extreme end, and I doubt that most people probably get five centimeters shorter by the end of the day, but it’s possible. But I’m sure most of us, our height changes a few mils here and there, so his point being is if you see someone for a bike fit at 8:30 in the morning, that’s different than seeing them at five at night, or four in the afternoon, because they have not been subject to gravity all day. So I think that’s an interesting concept to play around is that positional range, both we might say, like your acute training load versus your chronic training load, right? Your acute height, within the day, or your acute mobility or flexibility, versus your chronic and how are you making functional changes over the long-term, are you doing Pilates and yoga? Are you doing Eldo stretches? Are you working on are you strength training? Is that strength training going to make your muscles stronger and shorter or longer and more supple?


Jason Williams  14:59

So I think if you, if you identify a range that’s appropriate for that rider, and they’re going to work within that range, you know, then you have a position that’s very workable, and then you have the rider that’s going to adapt to that position. So, you know, I do believe that there’s a, if you find a position that’s within the range of the rider and that rider, spends some time, as long as it’s not on the borders of that range, they’re going to, they will adapt to that position and find that that position is very workable, very natural for them. You know, obviously, if that range is pushed, that’s when we find you know, discomfort, right? If you’re outside of range, then that rider will have discomfort. So, you know, you’ll identify riders, though, if a rider has been off a bike for a couple of weeks, taking some time off for the holidays, and they get back on, I’ve heard this a number of times from professional athletes, they get back on their bike and say, well, somebody changed my bike. Nobody changed it, but it’s been in a storage locker since you left your garage.


Colby Pearce  16:00



Jason Williams  16:00

And then they get back in the bike, and they’re like, “this is not my bike.” And then they spent a couple weeks riding it, and it’s like, “oh, yeah, this is totally my bike.” But you know that that first impression, there can be a highly tuned professional athlete that gets on their bike and thinks that somebody pulled a swap on them.


Colby Pearce  16:15



Jason Williams  16:15

So you know, there’s this this time of adaptation. If you find a position that’s within the range of that rider, and they give the time to adapt to that, and it’s an appropriate position, then it can be a very effective position for that rider.


Challenge of Deciding How Much to Adjust the Bike Vs. How Much the Athlete Should Adjust to the Bike

Colby Pearce  16:27

Yeah. That’s a good concept. To outline, maybe one of the core challenges, as a bike fitting is finding that balance between how much of the bike we want to adjust, versus how much do we want to ask the athlete to adapt?


Jason Williams  16:42



Colby Pearce  16:43

Because the athletes, humans are amazing, and we can adapt to almost anything in the short-term, especially if you tell them, if you get in this position, you’re going to win bike races.


Jason Williams  16:50

Right, right.


Colby Pearce  16:51

And people buy into that, then they’re, they’ll convince themselves to do almost anything, right? So that makes me think about that, almost say, authoritarian father in the sky, Dr. White Lab Coat paradigm, or archetype. You know, people go to a doctor, and they kind of think in our society, at least in Western society, we perceive doctors as these authority figures, that can answer problems and give us solutions and help cure our health challenges, and I’m not saying bike fitters are equivalent to doctors in any way, but archetypally, there is sort of a, I go to my bike fitter to fix problems scenario, and that does sort of invite some of the same energies of that of that archetype. I pay an expert, and they solve my problems. And that challenge, I think, comes in western mentality, which is the chance that, you know, if I pay more money than the problem is easier, you know, it’s quicker and easier, it’s a pill or it’s a, my back hurts, can you just move my saddle in the right place, and then it’ll go away. And of course, we know that it’s often, all too often, far more complicated than that. Occasionally, you get that Easter egg. I’ve had riders come in, where they’ve had ongoing knee problems for a long time, and then you look at their cleats, and one of their cleats has slipped, and it’s at like a 45-degree angle to the shoe, and you go, “Okay, this is an easy one.” But that happens about once every four years, right? So the vast majority, the time it’s diving into the fractal, solving the problem of the infinite layers of the human body, and trying to figure out what’s going on. So I had some greater point there, wow, that was a little tangent in the weeds.


Jason Williams  18:33

Something you kind of hit on that that rang true with me is sort of the placebo effect in bike fit, which is, you know, for me, it posed sort of an identity crisis as a fitter when you as a young fitter, or a new fitter, you learn the methodology, you apply the methodology, and you have success, and you know, okay, so the method works. But then, you know, farther down the line, you realize, okay, I’m going to suggest a new saddle for this rider, and they try it and they say, “Wow, this is great.” Like, is it really great? Or do you think it’s great, because I said it’s great? You know, and it’s, it becomes a little cloudy, right? I do believe, you know, if I recommend a saddle, I do believe strongly that I’m recommending something I think that they’re going to appreciate, doesn’t always work that way. But then, you know, you wonder how much me saying this is going to be great, affects their perception of it being great, and perhaps it really does make it great, because they believe it to be great. And if the fit is appropriate, the width is appropriate, the shape is good, doesn’t cause problems, then it’s great.


Colby Pearce  19:40



Jason Williams  19:40

I think there is something good to that, but it also can kind of cloud the waters when you get into recommending product or changes.


Colby Pearce  19:50



Jason Williams  19:50

But I mean, that is in our in our realm, is to be confident in our recommendations, to state it confidently, and to get their feedback. I don’t want to recommend anything that’s not great, you know, so I definitely want to know if they’re not, you know I don’t want you to just tell me, if you think it’s great, I want to know if it’s not great. It does pose a little bit of a you know a dilemma in bike fit, you know to really sus out appropriate changes, and make sure that they really are appropriate for the rider.


Striking the Balance of Selling the Client Equipment and Solving a Problem

Colby Pearce  20:18

Yeah, yeah. I agree, that takes us back to that white lab coat paradigm of I’m paying you for your expert opinion, which is all good, that’s why people sign up for a bike fit. But we have power as fitters to suggest certain things, I think that’s what you’re getting at, and so if you have certain products on your shelf, and Happy and I discussed this too. Happy doesn’t sell anything in his fit studio, he doesn’t sell saddles, doesn’t sell shoes, and doesn’t sell pedals. His objective there, his line of thought is that he wants to be able to give the client confidence that he doesn’t have an agenda to sell them a bunch of stuff, and leverage that expert opinion, and I totally understand that perspective, it makes sense to me, that’s not how I run my fit studio, I sell things because I view things like stems and handlebars as problem solvers. If a client comes in the door with, you know, 120 and they need a 110, then I don’t sell them, and they don’t have one, then it’s a showstopper, like how do we proceed with our fit? There are other ways to solve that problem, but I prefer to send the client out the door with as many solutions as possible. Then there’s that striking that balance between making a recommendation for particular saddle, or particular shoe, for a client that I happen to sell. I try to strike the balance by authentically caring products that I believe in, but also making it clear that my objective is not to sell the client things, it’s to get them the best fit possible, whatever that solution is. If the shoes I sell happen to be part of the solution, great, the reason I carry them is because they work for a lot of riders, but it doesn’t mean they work for that individual, right? There’s that authoritarian tension there, where we have to I’ll say work with a client authentically, and try to try to solve the problem in the best way for them, without having an agenda to sell extra stuff.


Jason Williams  22:06

Right. I think that’s a really important point, I you know, early on it was one of the lessons I learned in some of my first fits was, again you learn this methodology, and the methodology includes, okay get them on the right saddle, put the right stem on, adjust the handlebar, maybe put a different handlebar on. If you follow the methodology, and you recommend these parts, you could come to the end of that and the person just says, they just tried to sell me a bunch of stuff.


Colby Pearce  22:28



Jason Williams  22:28

That was the agenda, and so like I was lucky enough to get some good feedback from clients early on, to say I appreciate everything you did, but I did feel a little bit like you were trying to sell me stuff. So like I acknowledged that really early on, so a few years ago, probably 12 or 13 years ago, when I had the opportunity to build a studio from scratch. Okay here’s a room, let’s start from scratch, let’s make it the way you want it. I made a conscious decision to say, we’re not going to display any product, this is rider in the middle of the room with some technology to measure their position, and this is a rider first experience. We had cupboards and drawers with all the product I needed, but the product was not the point of the experience. I really wanted to put, literally the rider on a pedestal, you know we put the rider on a stand in the middle of the room, this is their session, it’s all about them. You need a seat? Oh, I do have that here, but the seat is not the focus of that interaction, so nothing displayed on the walls, nothing you know hanging on cards, in like a retail sense, it was not supposed to be a retail experience, it was supposed to be a rider driven experience. But yes, having the product that you support and believe in to help that experience, it is important to have it there, but just not as the primary you know experience that they that they see, and you know you don’t want that to be their first impression when they walk in the room.


Colby Pearce  23:53

Yeah, okay. Yeah, that’s a good point. So something else I want to ask you about, is how you feel about the tension between, I’ll say that there’s this balance right, because on one hand we’re trying to set up the bike for the physiology of the rider, and meet it for the demands of their event, and when we explore the physiology of the rider we can unpack that into, as you said, they’re pre fit evaluation, we’re doing a Thomas Test, or we’re looking at their hamstring flexibility, or whatever we’re looking at, how their spine bends when their hip hinging etc., How good is their hip hinge, right? Which takes us into Paul Chek’s primal movement patterns, he teaches there are six primal movement patterns that any sport can be broken down into or reduced to, and the first one a bike fitting is a hip hinge, that’s what it is it’s static hip hinge, and then a series of lunges, and then you could argue it’s a pole and a static push, and very little bit of twisting here and there, maybe more so in mountain biking when you’re driving the hips to corner and things like that. So when we look at that pile of data and then we’re trying to convert that into how they’re going to sit on the bike, and then we’re perhaps educating the rider a little bit on their posture, and what their shortcomings are, what their strengths are, in each of those categories. And we’re sort of unpacking all that, there’s I feel like there’s a tension between, first of all there’s a tension between education of the rider, and simply sending them out the door with what works on the day. That’s where my crosshairs tend to end up a lot of the time, that’s why my fits tend to be so long, because I feel like, I really prefer to teach an athlete how to fish rather than hand them a salmon or place kippers, whatever you’re value is, right? And that just happens to be where my passion is, I know not all fitters feel that way, and a lot of people just sort of want to button things on the day, and there’s no judgment on my end from anybody’s method, I’m just explaining what my line of thought is. I feel like there’s also a tension between asking a rider for feedback on a given change. Let’s say you raise their saddle 12 millimeters, and you ask them how does that feel? Because you want their feedback, that’s part of the process of engaging a rider, or maybe a more crystal example to use to start off with is you change their saddle, they come in on saddle x, and they go, “I’ve got some saddle sores, and I feel twisted on the bike” or you know, “I’m not sure if this is the right width, I don’t know sometimes I get numbness,” okay, let’s try a different model. And you use your experience to interpret their sensations and say, “I think this saddles a little more padded than you need,” or maybe it’s not padded enough, or whatever, it’s too narrow, it’s too wide. So you select another saddle, you say, “let’s try this one,” and they ride on for a few minutes, and they ask, and you ask them, how does this feel? And just as you said, because you are the expert, you’re wearing the white lab coat, metaphorically, and you’ve given them your opinion of what might work sometimes that influences their feedback on that saddle, and so there’s several points I want to make here. One is, that I think, there’s some aspects of bike fit that in my opinion are pretty cut and dried, meaning when I look at your saddle height, I feel like that is pretty much your saddle height, there’s a little range there, but if we go 20 mils higher or 15 mils lower, you’re gonna be out of that range, right? I’m just kind of making up numbers to illustrate the point, but there are other specs as aspects of fit could be more subjective and more, there are more solutions that could possibly work I’ll say, you could try a couple different models of saddles and maybe there’s one that’s a tiny bit better, but most of them would work most of the time for you, but the way to bear that out is over time. It’s gonna take you three or four weeks to try a saddle, and really get enough feedback to be able to report to me, did that work or not? This is where trial saddles or test saddles really come in quite handy, right? Or maybe some companies have a kind of money back situation, six weeks or something like that, I don’t know what the policies are. But that puts the ball on the court of the rider to make that decision and try it over a couple rides, you know, an hour ride, some rides of climbing, some rides with flats, blah blah blah. But what I’m trying to get at is, very long way to ask this question, how do you account for the tension between, here’s what I’ll say, people you can ask someone what they like when you make a change to their bike bit, but most riders don’t really know what’s going on with their own bodies, proprioceptive input or ability to have proprioceptive clarity is pretty low in my experience there are exceptions, gymnast, ballerinas, for example, lifetime athletes who are super tuned one category of person, most bike riders and bike racers don’t fit into that description, so prospectively, there not super clued in, so how do you account for that tension of, do you like this? And then you’re looking at it and you’re going, “huh, I’m actually not happy with this, but the rider is telling me they like this,” how do you how do you sort of equalize that equation? I don’t know if that was a clear question, you know what I’m getting at?


How do you Equalize the Equation of Client Feedback and Professional Opinion as a Bike Fitter

Jason Williams  29:07

Yeah, totally. So you know, I think the rider feedback, we as fitters, we need to hold that in high regard, right? We need them to give us good feedback, and we need to really honor what they tell us, right? We don’t want to be in the place where we’re saying, “well no, trust me that’s the right one,” even though they’re like, “I don’t like it, I don’t like it.” You know so we’re not in a place to try and force something that the rider doesn’t like, but if we make a change in equipment based on a symptom or a problem, and the rider feedback is positive, that’s a huge factor, but for me in my practice you know using the Retül equipment, the motion capture equipment, I also like to see a reinforcing change in their measured data, right? So for our practice, it’s a combination of the rider feedback, my visual cues, and what we would interpret as an improvement in the data. So if we’re measuring the rider, and we can identify a measurement in their motion tracking data that’s out of range, or let’s say a red flag in their data, and we make a change, and they respond both perceptively as an improvement, and the data improves, and it looks better to me, then that’s kind of this homerun of sort of feedback to say, rider likes it, data agrees, I think it looks good, let’s try that. So it’s kind of this combination of rider perception, data confirmation, and you know my kind of my suggestion of equipment to make that change.


The Method of Retül

Colby Pearce  30:42

Right. Okay, so let’s look macroscopically at the method of Retül, and I’ll just full disclaimer here, like I know Todd pretty well, Todd Carver, he’s the guy who pretty much invented it, right? Although I should maybe not say that out loud, I don’t know if that’s quite historically accurate.


Jason Williams  31:02

Yeah, so Cliff Simms kind of developed the technology.


Jason Williams  31:06



Jason Williams  31:06

Todd was the fitter biomechanist, who could sort of put it to use so to speak, so you know Cliff as sort of the inventor of the technology, had the vision for what the technology could do, but Todd, at the time, was working with Andy Pruitt at the Boulder Center for Sports Medicine, had a chance to use the equipment and said okay, we can use this in a fit context, and so Todd I think, was able to apply the technology in a fit context, so yeah invented the way the technology was used as an application.


Colby Pearce  31:36

Particular application, okay that makes sense.


Jason Williams  31:38

And kind of because of his background, using the motion capture lab at Boulder Center for Sports Medicine.


Colby Pearce  31:46



Jason Williams  31:46

So he had a motion capture background, and can see the potential for the Retül technology to push that to markets, right? To bring that to retailers to use in a in a shop context, as opposed to just in a lab or clinical setting.


Colby Pearce  32:02

Let me outline this, just so people are clear on what Retül is, I think most people have an idea, but i’m just going to give a really quick overview. So we put reflective markers on different biomechanical points on the body, right?


Jason Williams  32:18



Jason Williams  32:18

Tibial tuberosity.


Jason Williams  32:19

A joint center, or a location of prominent marker on the body, that we can repeatedly identify as a joint center, or a marker on the body.


Colby Pearce  32:28

Right. And you film those markers in motion, and then you basically, the computer software makes a simple stick figure to look at angle changes.


Jason Williams  32:36



Colby Pearce  32:36

So we can look at normative angles, for example, knee angle, hip angle, back angle relative to horizontal, right? And then, looking very macroscopically, fundamentally the method is that we compare it, we end up with a pile of data. Just for reference, like how many data points do you guys have in the Retül database? If you had to guess right now, it’s been going for what, 15 years?


Jason Williams  33:06

I mean it’s got to be tens of thousands of riders recorded, and the nice thing about the way the software has developed, is that it is sort of layered upon itself, right? So the first generation, Todd and some of the early founders went to professional teams and they measured these athletes, and said, okay right or wrong these are the best in the world at what they do, let’s measure them and quantify that, and say okay let’s learn from these pro athletes, let’s figure out how they’re so good. And so the foundations were based on the best athletes in the world, let’s learn about how they ride a bike, and then you apply that to everyday people, and then you get this combination of the best of what we know about the pro athletes, and then overlay the you know the everyday rider, you know the weekend warriors who go out and ride huge rides on the weekend, or even just people who ride you know 10 or 15 miles, you know, a couple times a week. You can overlay all of those data sets, and so what we have now after tens of thousands of riders, is a composite view of all of these riders, professionals and everyday riders, and our normative ranges are filtered from kind of this combination of data based on all of those riders.


Colby Pearce  34:18

Okay. So fundamentally, the method is, when someone is trained in Retül method as a fitter, what they’re doing is they’re comparing an individual’s data to a set, and they’re looking at how that individuals data compares, and they’re using orthodoxy as a reference, right?


Jason Williams  34:42



Colby Pearce  34:42

So when you see someone who’s an outlier, in a particular number, then that tells the fitter or something about that individual.


Jason Williams  34:48



Colby Pearce  34:49

That they don’t fit in the bell curve.


Jason Williams  34:50



Colby Pearce  34:51

My question is, why is that relevant? Because all humans are individuals, so if we build a house for an average man, that’s a man who’s got 2.2 children, who’s five point, you know, five feet, 9.25 inches, has 1.8 cars, has a fence that is, etc., so many meters long around their house property, has brownish eyes, etc., etc. Like I have yet to meet that human, right? So just to ask a pointed question, I guess, why would orthodox data, why would this bell curve be relevant to any individual who you want to perform a bike fit on?


Why Retül is Relevant to all Cyclists

Jason Williams  35:40

I think probably the, the biggest thing it can do for a rider and the fitter is to give some context to what they’re seeing with the rider on the bike. And you totally nailed it, the first place or the place where any fitter could go wrong, is to fit to the orthodoxy. Where the fitter is the practitioner in this case, is to interview the rider, and do the assessment. As you said, identify the individual needs of the rider to identify where that rider fits into the normative ranges, and to identify where that rider is going to break those ranges, where it’s appropriate that they break those ranges, and where it’s appropriate that they fit into those ranges. So we need to know who the rider is to understand how they work within the context, the framework of the data. Because you’re right, to fit somebody to the middle of range, I think a lot of people would probably do fine with that, but there’s a lot of people that wouldn’t. Like you said, that bell curve, you’d have 30% or 40% of the riders that don’t fit into that, you know, bell curve average, and you would be doing them a disservice if you try and put them into the middle of range. So the fitter needs to identify, is that rather going to break the range, or be out of range, and why? And then make sure that we explain that to the rider. This range says this for most rider, but when we did that Thomas Test, we identified that you were limited in this range, so I know that you’re going to be out of range in this measurement, and that’s okay, that’s intentional, right? So we have to intentionally interpret, and break the rules when we need to, for the rider. So again, the data is only a framework. But what’s nice is it does give some context, we can say your seat is lower than 99.9% of the population we’ve ever measured, I think we should maybe raise it up a little bit. And it’s not to say that’s my opinion, I don’t think you should raise it up, I’d say you’re at the 99th percentile of seat height range, maybe if we bring you into the 70 or 80 percentile, you might have a little bit less, you know, knee pain. So I think that’s kind of the key is, is also identifying if there’s an outlier in their data that coincides with one of their complaints or symptoms, if they present with knee pain, I’m looking for a flag and the data that says here’s why. And if it’s an outlier, and their knee is bothersome, and their assessment says that that might be a problem, like I said, that’s that sort of three-part home run, when we say router complaint, assessment, observation, data confirmation, let’s make a change. So yeah, definitely, the data provides context, but it’s not the fit to the rule, the way I interpret the data.


Colby Pearce  38:25

Right. Do you think someone who’s just starting out as a bike fitter, and they learn Retül method might lean more heavily on that data to kind of give them context or help them learn to interpret? Or are you guys teaching them to, hopefully not lean on that data too much?


Jason Williams  38:39

Sure. No, you know, what’s nice about the current status with Retül, is that it comes from this distillation of body geometry fit, which has been long standing, you know, specialized has been teaching fitters, to do physical assessments and to interview the rider and learn who the rider is for a long time, and then in more recent history, bring the technology in. We have a long history of teaching riders, or teaching fitters to understand the rider, the technology is a new asset. So yeah, we still really train fitters to learn about the rider first, and then use the data as kind of a complimentary framework for interpreting how that rider sits on a bike.


Colby Pearce  39:20



Jason Williams  39:20

But to your point, I do think the data does give some important context for a new fitter to say, okay, you know, you can look at the rider, but then if you see the data, and you see how much of an outlier that knee angle is, you’re, you’re confirming your eye and you’re perceptions as a fitter. The data can also help to confirm what you see as a fitter by putting it into a data context.


Colby Pearce  39:45

Right. So you were saying that three way triangle is okay, let’s say the rider has a history of knee pain, anterior knee pain, for example, and then you look at the data and it suggests that they’re on the low side for satellite, and then you look at them as a fitter, and you say, “yeah, they’re saddle looks low,” then you’re, you’re saying that then it makes sense to raise their saddle height? Is that fair?


Jason Williams  40:09

That would be my, sort of context, is yeah, like, I don’t make changes lightly. You know, I don’t want to have a rider in the stand and take a quick peek and be like, boom, boom, boom, let’s make all these changes, I want to lay out this this context layout this sort of ordered approach, and to give them the the reasons for making a change. So that you know, there’s a pretty solid rationale behind making a change because I, you know, I don’t ever make a change lightly. I make a change with very intentional, you know, methodology.


Colby Pearce  40:45

Yeah, reminds me of a funny, I think there’s a Cat3 meme, like Instagram thing that’s going around, and some point, I got to put this out and put it on my wall, but there’s one that was like, “bike fitter uses random number generator to make saddle height,” you know, and I think that is a sort of a little, you know, whispery bad joke in the minds of a lot of people, they go to bike fit, and I’ve certainly heard stories about clients who go to bike fits with three or four different people, and they come out with three or four different saddle heights that are wildly different. And I mean, I think there are several explanations for that, and I’d love to hear your comments on this. But from my perspective, bike fit is this weird universe, it’s like this collision of really old school, Italian wives tales, that’s like, probably 85% of that is pretty much garbage, no offense to any Italians out there, but it just needs to be looked at as ancient history and moved on from and we’ve evolved, but there’s maybe I don’t know, I’m making this up as a number, maybe 50% of it, that’s like, okay, that happens to work out pretty well, and we can hold on to that, that’s a reasonable, whatever platonic truth, I guess you could say about how the body sits on a bike, maybe there’s a higher percentage that I’m not really sure, I haven’t thought about it too much, in terms of the numbers, but I think there’s that old school line of thought, which isn’t very developed about cyclist and cycling. And then there’s this new world of people who have conditioning, training in strength and conditioning, you know, look at the body from different lenses, the lenses of Pilates, or Eldoa, or deep anatomical knowledge, or strength conditioning from a different level, you know, and, and we can apply those rules to this old school bike fitting world and get this collision of sort of weird outcomes. And so many cyclists, particularly the ones that have been riding their bike for 30-40 years, myself included in that category, it’s easy to sort of hold on to these wives tales and go, Oh, yeah, but, “you know, your knees should graze the top tube when you pedal because that’s aero,” and you talk to any modern strength conditioning specialists, and if someone coached you in the gym to do a squat with your knees, you know, grazing, fictitious top tube, Like, that coach would be like, what are you doing? You know, you’re about to shred multiple aspects of your body. So I don’t know, what do you what do you think about that collision of old and new world fitting and how that plays out? I think that’s why we get so many weird potential, I think that’s why we get so many disagreements or not cohesive lines of discussion and how the rider should sit on a bike, right?


Collision of the Old and New World of Fitting

Jason Williams  43:33

You know, it’s interesting, because some of those old methods, you know, came, you know, we’re distilled from again, racers, right? They pulled the measurements from the best in the world, and let’s learn from that. And then it’s still the case today that a lot of, you know, a lot of riders out in the world, they see that pro that they think is cool, and they want to match that riders position, even though, you know, we as fitters might say that that person has no right, right or no position riding that riders position, but they want to and that’s like, what makes them excited about their new Tarmac.


Colby Pearce  44:05



Jason Williams  44:06

But I guess my point there is that, you know, the pro riders and the elite athletes have a position that does let them perform better physically, but also, you know, the handling of the bike, and the way the bike behaves underneath them is an important part of that calculus, right? They need that bike to, to descend well, to climb well, to corner well. So there is some, I think some of those kernels of truth in those old school methods, you know, I think do still resonate in making sure that the bike behaves well underneath the rider, you know, there’s these kind of old wives tales about how a bike should fit, and I do think that has some, you know, kind of resonance in the way the bike might corner and behave on a descent, because I think as you know, we can identify a fit that is super comfortable and feels great, but then you get speed wobbles or you get you know, some of these ride dynamic characteristics that are not ideal. So, you know, for us as a fitter, we also need to weigh in, like, how is the bike going to actually behave? You know, it’s one thing to fit them comfortably in a fit state studio in a stand, and say it’s comfortable, I’m super happy.


Colby Pearce  45:16

Now I gotta go around a corner.


Jason Williams  45:17

Yeah, exactly, we would be remiss to sort of not address the aspects of how that riders bike behaves when they’re at speed.


Colby Pearce  45:25



Jason Williams  45:25

And I think, you know, I’ll acknowledge, I’ve probably failed at that a number of times, you know, like really driven to get that fit and that rider happy in the studio, and then realize, maybe that bike probably didn’t handle so well on the road. So I mean, for me as a fitter, my evolution now is kind of thinking a little bit more holistically about, you know, how that bike behaves in a, in a larger sense than just purely comfort and, you know, neutral position.


Colby Pearce  45:53

Yeah, or power production, perhaps, right? Yeah, I think that’s a challenge for a fitter, because most fit studios are, mine included for many years, recently, I made a small change to this, but I put the trainer and move them on a platform, on a Cirrus MP1, which you know, rocks and moves back and forth. So I have a little bit of dynamic aspect of fit, I’ve also encouraged riders to ride roller sometimes when possible, if they’re familiar with that, I’ll have them learn in the studio or try it. And then the bike is moving a little more organically like it would on a road, but that’s still only 5% towards the direction of actually riding down, you know, Flagstaff, which is a local climb, 30 minutes long on the way up, you know, eight minutes long in the way down, lots of hair pins, and real corners, and high speeds and steep grades, and so you want your bike to be able to go down that stuff. And we don’t really have a way to put a rider in that scenario in a fit studio, because their bikes and our trainer.


Jason Williams  46:48



Colby Pearce  46:49

And we’re looking at things like saddle height, and saddle offset, we have to use our crystal ball a little bit to look at where the center gravity is and see, okay, are they long and low enough over that wheelbase? But at the same time, things aren’t so extended, they can’t move their center gravity to maneuver the bike around corners. And then there comes back to the rider education, you can put someone in the perfect position to be able to corner a bike fast, but if their technique is dreadful, won’t matter, they can still ride straight off the side of the road. So there’s all those challenges, but bike fitting isn’t really set up as a practice in a way that allows us to actually see a rider go around a corner, unless you go out for a ride with them. Which I do that with some of my clients at times, I found that’s where I’m going to do on, on days, when I’m going to do a full fit. Sometimes I’ll meet the rider and we’ll ride for an hour first do coffee ride, and then I get to get to know them a bit and talk to him about their issues and their what’s comfortable on what’s working, what isn’t in their experiences, stuff like that, and that’s kind of a cool way for me to solve that problem. But of course, then it becomes like an all day thing, which I’m fine to do that, but you know, you can only serve so many people at a time like that.


Jason Williams  47:57

I’ve always thought I mean, that’s sort of the sort of holy grail of a bike fit experience would be, you know, a ride along.


Colby Pearce  48:05



Jason Williams  48:05

A fit studio session, and then a ride along, and then a follow up or, you know, with Valmont bike park in town here, take that rider on their mountain bike and do some suspension tuning, and do some fitting and then ride over some obstacles and see how they actually are sitting on the bike in the real world, as opposed to when they’re static in the studio.


Colby Pearce  48:25



Jason Williams  48:26

And it is it’s a it’s a missing link in our practice, I’ll acknowledge that, it’s something that we have always, you know, kind of had the same vision, like, yeah, ride along would be great, but, you know, timing, and otherwise, it is a it is a challenge. And then, you know, to charge appropriately for that amount of time, you know, it would price a lot of riders out of the experience, which, you know, I try and be very inclusive, I want riders to get fit more than try and squeeze an extra dime out of them.


Colby Pearce  48:55

Right. To charge for your time too.


Jason Williams  48:57

But to value for your time, the amount of that would cost to do a day session, it’s prohibitive in a way.


Colby Pearce  49:04

Yeah. Yeah, I agree. I mean, I do have riders who come from out of state to visit me and they plug down for hotel and airfare and stuff like that, and a lot of times when an athlete’s already going to that level, I’ll write them an email and say, “Hey, why don’t we meet at you know, a couple hours early, we’ll go for a ride first.” And for me, that’s a value add for me, because I from my side, so I don’t charge them for that additional time, in that case, they already put down quite a bit of money to see me for what’s gonna be most of the day anyway, right? So from my perspective, it’s sort of a way for me to get a bike ride in, but also help them more at the same time and help distribute my workload over a greater area, which can help offset some of the brain damage of trying to get my head wrapped around everything that’s going on. So anyway, that’s just the way I tackle that problem sometimes, but Yeah, I agree. I mean, we do have some good resources here, we’ve got good road riding and we’ve got Valmont Bike Park, so that’s not a bad idea, I mean, you’re both of our studios are super close to it, but you’re gonna almost throw a rock and hit it.


Jason Williams  50:00

Pretty much, there’s a trail out the door of our studio that can go straight in Valmont.


Colby Pearce  50:04

That’s pretty cool.


Jason Williams  50:06

It’s not epic Colorado trail riding, but it’s a great little city park that has some fun trails and so really nice to get a chance to zip over there and ride a little bit sometimes.


Professionals Don’t Always have the Perfect Bike Fit

Colby Pearce  50:18

Yeah. So rewinding just a bit to what you were saying about pros, and two points I want to make there, one is that the original Retül data set was based off of pros, which I think is interesting because that probably skewed the data to a point. I mean, okay, let’s say you have just to pick a number, you probably have more than this, but let’s say you had 10,000 data points in the in the database, right? And 1000 of those were pros or something, I don’t know I’m just making stuff up, so all right, 1/10 of the data is pros and as we, to rewind even further into our conversation as you pointed out, we have the colloquialism or the wives tale, the pro who stops riding their bike for three weeks and then gets back on their bike December 1st, and goes, “who moved my handlebars so far away,” right? Oh man, “this thing is really uncomfortable, and I’m so tight,” now maybe that’s because the pro just drank beer and sat on the couch for three weeks because they raced their brains out all season, and that’s fine, hopefully not too much beer, but they and if they didn’t do any gym time or mobility work or flexibility training then they’re really tight, and the bars are gonna feel like they’re million miles away, and they’re reaching to you know football field across their top tube, that was a terrible analogy but, so my point being is that pros adapt to an extreme position. So when we, so by definition, also we’re looking at when you set a data set at the top end based on that adaptation curve, somebody who’s doing hours and hours and hours of riding and forcing their bike to adapt to that extreme position, arguably you’ve got a little bit of a problem there because somebody who’s training 22 hours a week, or 25 hours a week, or riding you know 1200 miles a year, versus a recreational rider who’s riding you know 400 miles a year and training 8 hours a week or 10 hours a week, you could very well say that you don’t really want the amateur to use that bar as something to shoot for. Now I know that’s a small percentage of the data, and I’m sure that bell curve is now shaped by the majority of your user group, or of cyclists on the whole so that’s probably shifted that curve so we see that, but the other point I want to bring up which I think immediately comes to mind is that, I’d love to know if you agree with this or disagree with this, I think that we as amateur riders, I’m including myself in this category too, I’m training 8 hours a week, 12 hours a week, if I’m lucky right now. We tend to look at pros, we emulate their positions, and we look at them as something to aspire to, but that logic doesn’t make a lot of sense, because they’re training two or three times more than I am at the moment, or we are all say, as a user group. But two, also we tend to think of pros positions or maybe I think let me be clear on my language here, I try really hard to think about or imagine what other people are thinking, right? It’s a habit that I’ve noticed humans have, is really not constructive. But I’ll say that I can imagine that some people might believe that pros, their positions are optimal or optimized, and as a thought experiment, I’d like to use the thought experiment to illustrate the point that that’s not really the case. Many pros are already by definition, will say best, the .1 of the .1 of the top percent, and that just happens to be because they won the bike racing genetic lottery, which for the record is a really random lottery because if we were in a tribal system they probably would have died because people don’t make bikes in a tribal system, you can’t use them to hunt cheetahs or run away from cheetahs, or hunt antelope or whatever, you use your feet that’s how you get around that’s how you do things, that’s how you go get water etc.. So anyway, for the record those of you who are really amazing bike racers naturally, unless you also have a broader spectrum of talent, I’m not bashing you but, I guess I am.


Colby Pearce  54:25

So what am I getting at? I like when we look at the path of how a pro athlete arrives in their position, their final position in which they win a tour stage, or they win you know a classic, or whatever or they win an Olympic medal on the track, that cacophony of events isn’t necessarily what we think it might be from an external perspective. We assume that because they’re performing at the World level it’s easy to assume that things have been optimized, and that their position that they’re in is some perfect result of an equation of the ultimate fitter, you know, the ultimate mobility training, a perfect execution of all those daily mobility workouts or weekly for years and years, and that that rider is injury free, and that rider is perfectly functional, and their performing at their physiological and functional peak. And you’ve worked with lots of pros, the top in the sport as of I, we should know this is not the case, like a lot of pros are held together by kinesiotape, and super glue, literally. And so when we when you see what I see, I look at a Pro Peloton and I see a lot of, to be blunt, disastorus fit.


Jason Williams  55:43



Colby Pearce  55:44

But the riders are so good, they’re making the best of that. And because of that, the first point you made is that a rider adapts the position, so when we tell them, this is your position, go adapt to it, go do, you know, 6,000k in the early season in this position, the human body is amazing. And again, when that Pro has access to constant massage therapy, and a physical trainer is going to help them offset their constant nagging injuries, and hopefully they’ve got good nutrition and hopefully they’ve got good support in all those areas, then they can patch work themselves through that 6000k of training to get to the point where they win a early season race. And then we see the photo and we go, “Oh, well, the position looks kind of funky.” But man, she just won that classic, she just won that stage race, so she must be super dialed even though I think her saddle looks really high to me, but or too low or whatever.


Jason Williams  56:38

It’s so interesting to, you know, what are they? The armchair, you know, the armchair fitter.


Colby Pearce  56:43

Right there.


Jason Williams  56:44

You’re watching bike racing, and you know, these, these racers are in the hurt locker, they’re in the front of the bunch, they are just giving it everything they have, and then you have people that want to emulate that position.


Colby Pearce  56:57



Jason Williams  56:58

It’s a disastrous, you know, approach because that rider is in a world of hurt, just doing everything they can to turn over the pedals and get to that finish line first, has nothing to do with where their bike even is in space, right? See, we see their body and what their body is doing on the on the race cam footage, and that has nothing to do with you know, where they ride the bike 99% of the time, but also, you know, where their actual bicycle coordinates are in space.


Colby Pearce  57:26

Usually, because their effort is so extreme that they’re all over the place, is that you’re saying?


Jason Williams  57:30

What we tend to see on the footage is the breakaway or you know, the lead of the bunch.


Colby Pearce  57:35

Extreme moments.


Jason Williams  57:36

Yeah, that’s a very particular period of riding, you know, I mean, there’s Milan San Remo, there are six hours of riding, you know, the section we see those last 30k has nothing to do with the previous five and a half hours that gets to that point.


Jason Williams  57:52

And so, you know, I think that is, it’s a trap to get into really focusing too much on what we see, you know, in that, you know, in that footage, I don’t know, that’s probably half the point for what you were getting at. That’s certainly one aspect where, you know, people look at those positions, and certainly not a great idea to try and emulate that. But I think your bigger point was to say like, if we use these propositions as a model, and use that is an aspirational goal for fitting, even that would be misguided, because, you know, yeah, their position is also very tailored for aerodynamics, and for maximum power production, and in some cases for climbing to the, you know, if they’re a GC contender, they you know, they have a position that’s really tailored for optimized climbing, and that’s not maybe the rider that rides here around Longmont out on the flats, you know, so, the professional model, I don’t think we do well to aspire towards that position in some ways, but I also think we would do well to learn what we can from that position about why they ride that way, and why it is that they self-select, or, you know, it’s kind of this, um, those positions are distilled out of tinkering for years, right? I mean, as you know, it’s like, some of these Pros will tinker and tweak and have fitters and have mechanics and make a lot of changes in that position has been sort of trickled down through years of use, and so I think it’s important to acknowledge the benefits, and what we can learn from that position, but also take it with a grain of salt, to know that that is a very elite pointy end of the stick position.


Colby Pearce  59:31



Jason Williams  59:31

That 99.9% of us could, couldn’t or shouldn’t try to ride, but what can we learn from that? And if there’s an exaggerated change for that rider, can we take a 10% lesson from that and apply 10% of that direction for you know, a local athlete who wants to, you know, do the best on the left-hand Canyon climb, you know, so, I think distilling some lessons from that is important, but just, you know, straight up emulating position would be totally misguided.


Having a Personal Agenda is Only Going to Fail the Rider

Colby Pearce  1:00:04

Yeah. That’s a good point, well I think you made a good point, I think you’re right, a lot of pros do have positions that have been distilled over the years and that distillation process is what we don’t really have a window into, I mean maybe an experienced fitter does, and you can see a little bit about how things have evolved like, Geraint Thomas, is a great example, his position has changed radically in the last few years he still had great success in that and to me that suggests that Geraint is the point .1 of .1 or .1, he could probably ride, you know hobby horse or a tricycle and still win pretty big races. Brad Wiggins probably another example of that. I think that’s interesting, but I also see some athletes who make it to the world to a level, and I’ve worked with some of these personally, who have positions that I would argue are well off the mark of what in my opinion is optimal, but they’re making it work. It’s a testament to not only the perseverance of the athletic body and spirit, but also how things can slip through the cracks. I think, it’s you know, as a bike fitter who goes to a camp, a team camp, to work with professional athletes, it’s a bit of a tricky situation, because a lot of these athletes have established relationships with people that they’ve been working with coaches or fitters, that they’ve been working with for years and years, and then they come to a camp and maybe they have an experience where the fitter has an agenda and they want to, there’s this negotiation of egos and agendas. I guess I’ll say it, and then the rider of course wants to perform well, but maybe they’ve got an investment or a good relationship with people in their camp, their personal sphere of influence, their own performance team, and maybe those people are not within the professional team that are hired by frequently, they’re not, and then we have this fitter come in and they’ve got this their own philosophies and beliefs about bike fitting and maybe those two spheres don’t have that much overlap. So there’s a negotiation there, right? So when I’ve worked with professional teams or professional riders, I’ll say, I kind of try to make it clear that I don’t really have an agenda for an outcome, I’m just there to help them. And i try to offer them my perspective and my honest opinion, really that’s how I approach any fit, right? But the point being, is when I walk away from a camp I may or may not have had a change on an athlete’s given position, or an influence I’ll say, even though from my perspective that riders position isn’t really optimized. All I can do is offer my honest opinion and let them choose to navigate the waters. It’s entirely possible that you may be witnessing professional riders whose positions, are in my opinion, far from an ideal outcome or execution, but they’re making it work and they’re making work at the world level and maybe they’re even winning races. That doesn’t mean that things couldn’t be optimized, right?


Jason Williams  1:03:00

I think it’s an important point that, you know, coming into a situation like that whether it’s a retail fit scenario or a professional team camp with a personal agenda is only going to fail.


Colby Pearce  1:03:12



Jason Williams  1:03:12

But if you come into,


Colby Pearce  1:03:14

Or a corporate agenda, you could say?


Jason Williams  1:03:15

Exactly. But if you come in with the clear agenda that your agenda is the riders priority, and, what is their priority? Let’s figure that out. But I think we’re we’ve been able to leverage some techniques or technology with a good effect is giving the rider and the coaches and the teams some data to work with, and again that’s kind of where the Retül data has a benefit, is it’s not my opinion it’s not my agenda it’s just the data, right? Let’s look at these numbers, let’s interpret these numbers, let’s see where you are within that framework, and then if there’s appropriate to make a change based on the Retül data, we do that. And you know the tradition of you know, okay, here’s your team bike put a 130 stem on, cut all the fork off, you know, slammed as long and low as possible.


Colby Pearce  1:04:09



Jason Williams  1:04:10

That came from a long history of pro cycling, you know, for us as fitters we’ve always laughed at how absurd that is, but when we go to these team camps now, we can actually look at a position and say, okay with that 130 stem on slammed you are off the charts, even for pros, you’re lower and longer than anyone we’ve ever measured then maybe we back off a little. It’s not my opinion, it’s just here’s where you are in the data.  Where we’ve been able to sort of take that to a different level in the last few years, is to integrate some physiology testing with the metabolic kit and using the consumed Vo2 measurement techniques to actually measure physiological performance in different positions, and actually quantify using data, we could say that position is costing you physiologically, it may aero but you’re also paying a big price physiologically. And so we can again provide them, if you want to ride there and it’s aero, okay but we’re saying that that actually is costing you physiologically a penalty, if you’re willing to pay that, okay, but we can inform them provide them with some insights on the physiology side, on the biomechanical fit side.


Colby Pearce  1:05:22



Jason Williams  1:05:22

Give them the information and then if they’re like all in, let’s make a change. So again, it’s providing the context the framework.


Jason Williams  1:05:30



Jason Williams  1:05:31

To then, let the rider have some buy in let the coaches have some buy in to the reasons why we’re making a change. Again, we don’t ever make a change without a very methodical approach to why we’re making that change. It’s not just because it’s my opinion, it’s not because that looks crazy, it’s you know there may be a physiological cost, and that position in the Retül data set is just off the charts, let’s bring you into a range that has less physiological penalty.


Colby Pearce  1:05:59



Jason Williams  1:06:00

More biomechanically neutral, more comfortable and, “wow I can see the road,” I mean you hear this from riders, like “I can look ahead comfortably, like it doesn’t hurt my neck anymore, wow.”


Colby Pearce  1:06:09



Jason Williams  1:06:09

So you know, that’s a that’s a supplemental benefit, right? When we have a physiological benefit, a fit benefit, and they can actually see down the road better and their neck doesn’t hurt, you know, it’s that kind of three-part like confirmation again data driven decisions and positive rider feedback that really hits that homerun for like this is a positive change, so that’s kind of been interesting in the last few years been a really fun transition to provide more layers of data to let coaches and riders make decisions, and we’re just facilitating that process to give them the information take it or leave it, right? You know if you want to still slam that position and ride as low and aggressive as possible, okay, but here’s the reasons why we think that may not be ideal.


Jason Williams  1:06:57

And so just to be clear when you’re talking about the metabolic cost, you guys are using Vo2 with inspired and expired gases, and then you’re looking at power. So what you’re doing is changing position, you got the baseline, right? As an example, then you change the position, maybe you raise the bars, maybe you lower the bars, and then you simply look at amount O2 to consume versus watts made, is that correct?


Jason Williams  1:07:17

In some ways, yeah, there’s a couple layers of interpretation that goes into the different positions, but generally we’ve always had this context and when especially as we built the wind tunnel, a number of years ago, we had a number of riders come in and we would find this super low CDA, like really aero position, right? I mean to kind of video game that process and find the most aero position possible but, you know, I mean people go out on the road and like, “I can’t ride there for more than five minutes,” right? And so like, kind of learnings there was aero is so important, but we’ve always said this as fitters, with kind of this notion that like aero is only as important or as good as you can ride in that position, right? So you need to be able to maintain an aero position for it to be arrow.


Colby Pearce  1:08:01



Jason Williams  1:08:02

And we had this notion for a long time, but with the metabolic analysis we can actually define the window that a rider, just like with bike fit, you know, there’s a seat height range that a rider could ride.


Colby Pearce  1:08:15



Jason Williams  1:08:16

There’s also a handlebar height or a physiological range that a rider could ride as well. Our agenda is to kind of identify the limits for an individual, where that rider starts to pay a penalty that’s significant enough for it to be a problem. So if we can identify a stop point, and say, okay this is where low is too low.


Colby Pearce  1:08:36

This is where things fall off a cliff


Jason Williams  1:08:37

Exactly. Yeah, that’s exactly it. Find that inflection point where the data falls off a cliff, then we know there’s a bound and if we stay within the bound, we can fine tune within that context.


Colby Pearce  1:08:50

Right. But then how do you account for the amount of adaptation a rider can have to that position? I mean let’s say that let’s say you put them in their super their best CDA, their most optimized CDA, super low drag whatever it is, and then you say okay, but your power is well off the cliff at this point.


Evaluating Riders Compliance with the Adaptation Protocol

Jason Williams  1:09:06



Colby Pearce  1:09:06

So then we’re going to back you up, and we’re going to lose you know x amount of CDA. We’re going to gain drag, or increase drag I should say, because we’re going to raise your bars this amount, and they go, “well but I really want that low CDA,” and you go, “cool knock yourself out.” So you respect the opinion of the rider, you slam that stem, they go out the door with that super low CDA, and then they go and they’re stretching, and they’re foam rolling, and they’re getting massage, and they’re doing soft tissue work, and they’re riding in the position, and they’re not just riding their TT, let’s pretend this is a TT bike because this is a common scenario, they’re not just riding at one hour a week, they’re riding it, you know, nine hours a week. And they’re doing efforts in it, and over time, this hypothetical thought experiment optimal rider comes back six months later, and sure enough they’ve adapted to this position, right? And they’re maybe they’re road bike FTP is x and their TT bike FTP is 10% less or 5% less, but when you started out in that super low position it was 20% less. So this is part of the equation of evaluating riders compliance with the program and being realistic about how good they’re going to be in an adaptation protocol, versus someone else who just wants the bars to be super low so it looks cool the coffee shop, but their back is hurting all the time and they’re barely making it down to the bars, and they do that thing where they’re reaching to the tops of their fingertips because the bars are too low.


Jason Williams  1:10:36

Yeah, that’s an important part of the calculus, right?


Colby Pearce  1:10:38



Jason Williams  1:10:38

When we look at a rider, the Vo2 values and their raw values are one piece of the puzzle. But are they a time trial specialist? Are they committed to work to that position? Are they adaptable? And that’s actually part of the conversation with the coaching staff and the physios, in to say like, is this rider going to be able to adapt and modify this sort of Graeme Obree, you know, can they assume a position? If it has race benefit, will they be able to make that change, are they committed to make that change? So that side is also part of the calculus. We say, “okay we’ve got the data from the Vo2, we’ve got the Retül data,” we also need to know who that rider is and analyze how committed they are to a time trial position, or an aggressive position. You know sprinters who just want to get through the TTT, right? They just are gonna hang in the back, and kind of ride and they’re not a time trial specialist. But then you have other riders who they just they’re going for World Time Trial Championship, and so they are committed at the highest level to that position. We might push the bounds a little bit, that said it’s not as simple as if a Vo2 is a penalty, and we come up we lose CDA, we’ve seen any number of times that an an increase stack height in the pads can actually improve metabolically and improve aerodynamic.


Colby Pearce  1:12:07

Right, right.


Jason Williams  1:12:08

You’ve heard this before, but the outdated notion that slam is aero, it is for some riders but not for all.


Colby Pearce  1:12:17



Jason Williams  1:12:18

And so riders often who are paying a metabolic penalty, they’re not comfortable, they’re so slammed, they’re also not aero because they’re fighting with that position.


Colby Pearce  1:12:26



Jason Williams  1:12:27

So if we can get them comfortable, get them in appropriate fit position, and they can just relax into that, their CDA, for sure, can come down in a lot of cases. So we’ve seen that a number of times when we get you know metabolic benefit and aero benefit by raising the pats. But again, it’s individualized, right? To say that is going to work for everybody is not the case, there are some riders who for sure still get a low CDA, and you know, the aero variable is a high priority. I mean we need to make sure that that rider maintains good aerodynamics, some riders do pay a penalty when they come up and that’s part of this balance of you know fit, metabolics, aerodynamics, and kind of finding this balance for each individual.


Colby Pearce  1:13:11

Yeah, yeah. That’s a great point, I love this discussion, because well I’ll make two broad points on this. One is that, you know, especially in Zwift world and TrainingPeaks world, we tend to think of people’s performance and bike race being dependent on their FTP. The easiest way to compare that, apples to apples, is to convert it to watts per kilo.


Jason Williams  1:13:32



Colby Pearce  1:13:32

But I’ve made this point many times in the podcast, I won’t beat it to death, but the horse is already down so I’m going to kick it once. Watts per kilo only applies when you are racing your bike in hill-climb in a vacuum, that’s yes, watts per kilo is of course a predictor of outcome in bike races, but nearly every bike race 95-98% of all bike races, aerodynamics is a big part of the outcome, and it’s much harder to quantify CDA. So that’s the only reason we don’t use that reference, but the reality is we should all be looking at watts per gram of drag, that’s a far bigger outcome of performance, far bigger predictor of race outcome than watts per kilo. It’s just watts per kilo is easy to measure, because all you need is a scale and a power meter. But to get CDA, you need a wind tunnel, or one of the crazy devices you put her handlebar that requires a software engineering background to actually get set up and work, or you need to go use a Chung Test, which isn’t the most complicated thing in the world, but is reasonably complicated. There are a few other methods you can use, right? But to find your CDA, basically if do a bunch of research and figure it out, and also CDA is not as easily defined, because CDA changes with helmet choice, jersey choice, handlebar position, right? So we don’t know these things are not as easy to track, but they’re far bigger outcome predictor for race performance, which is ironic. I also think another point you made is really good, that the old school model is lower is more Aero. The fact is, there are a lot of riders who can benefit from higher, higher arm pat position in aero bars, for example, but get improved drag numbers, how is this possible? Well, in many cases, the line of posterior tension becomes too high when you fold up the hip excessively, so we release that lever a little bit and you get the riders, then the riders ability to turn ahead and bring the shoulders up to the ears increases, and the net result in drag is a lower drag, right? I mean, the takeaway here is that fluid dynamics are really complicated. And you can have a good wind tunnel eyeball, if you’re fitting someone on a TT bike, and you don’t have access to a wind tunnel in your backyard, like you guys do in California, but you don’t have that here, you’ve got the Matt Cart, so you can do a little bit of that, but you’re still basically looking at a rider and sort of estimating the aerodynamics based on your wind tunnel experience, right? Is that a fair?


Jason Williams  1:16:01

Yeah, no, I mean, I think something that you kind of, caught on to there was, I think of the recent film that came out, Ford Vs. Ferrari, I mean, just kind of a fun car movie, you know, lots of good revving engine sounds, and you know, just good car racing. But, you know, they, they build this car with this mega engine, you know, like mega powered Ford muscle car engine, and the driver drives it and he’s like, “I can’t go around a corner, it’s gonna come off the ground, the aerodynamics are totally off, the handling is off.” So you can have the super high watts per kilo, but if the CDA is not, you know, appropriate to kind of handle the bike and move through the air appropriately.


Colby Pearce  1:16:41



Jason Williams  1:16:42

That big engine does nothing, right? So, you know, the big engine is important, you got to have a big engine, but you also got to have the aerodynamics and the handling and the behavior of the bike, the ability to break I mean, stop and turn corners is all part of that, you know, winning race car, and winning, you know, bike race, right? So it’s this combination, I think you’re right, like watts per kilo. It’s easy to, it’s easy to measure, and it’s in, it’s easy to kind of quantify that and it’s something we can all chase a little bit, right. I mean, you’re on Zwift and you’re on you know, your trainer at home, and it’s fun to kind of try and push those, push those numbers up a little bit. But yeah, the CDA, and the handling, and the braking, and the cornering, is all part of that puzzle.


Colby Pearce  1:17:23

And maneuvering in a Peloton, and that’s something that gets overlooked in the U.S. because we have giant roads and small fields, but every road is basically an alley, right? Or gopath, and you’ve got huge pelotons, and everyone can handle their bikes better, handling becomes really important.


Jason Williams  1:17:39

Yeah, because I mean, we’re seeing so much of you know the crossover from cyclo-cross these days, where people are coming from this cyclo-cross foundation of, you know, hopping barriers and riding through mud and, you know, all the kind of variables of bike handling that we see, I mean, all of the current stars in cycling right now, have come up from this cyclo-cross foundation in European cross and, you know, European cross, so, at such a high level and then the riders that make the jump from you know, World caliber cyclo-cross racers, straight in the road peloton, and they’re right at the front of the bunch, you know, and so, it’s interesting to kind of see that that sort of crossover. And even for mountain bike, you have a lot of, you know, pro athletes who are, you know, jumping all three categories, racing elite mountain bike, XEO, racing cyclo-cross, and racing in the road. So, it’s cool to see that we have this sort of crossover in specialties, and that the cycling world is kind of identifying that is really a positive and not the sort of specialist you know, just mountain bike purely or road purely, that you actually have riders that are bridging all categories, which is really exciting to see.


Colby Pearce  1:18:46

Yeah, it’s cool. Cross disciplinary gives spectators a lot cool stuff to look at.


Jason Williams  1:18:50

People love it.


Colby Pearce  1:18:51

And watch, and I’ll say, I, I definitely agree with that line of thought, in that vein of thought, um, that’s super cool. I think also, I’ll say that we’re getting we kind of ripped ourselves off a little bit because we had that previously, in Marianne Vos, we just, she’s woman, so she didn’t get as much attention.


Jason Williams  1:19:09



Trends in Bike Fitting: Slamming the Saddle Forward

Colby Pearce  1:19:10

Which kind of sucks for the ladies, but they’re catching up, hopefully, in recognition. Okay, I want to ask one very specific question about modern, like position philosophy and what you think about this, and this is something that I’ve thought a lot about and discussed quite a bit in my pods, but it seems that right now, in the world of bell bottoms, we’ve gone away from skinny jeans, sorry, in the in the world of denim, we’re onto bell bottoms now. Skinny Jeans we’re in now, now we’re circling back. And by that, I mean, it is the thing to slam the saddle forward on road bikes, and there’s a lot of, there are a lot of pros and a lot of amateurs who are into this, let’s find the saddle forward and put 131-140 stem on. I presume that, I think that’s born out of two basic lines of thought. One, I think a lot of people are focused on not making the hip angle too acute, that’s just to define that so people know I think most people know what this is but, when your thigh comes up to the top of the stroke at twelve or one o’clock, when your leg comes up to that point of that stroke the thigh gets really close to your ribcage, and that hip angle becomes very acute and that’s something that we’ve kind of borrowed from triathlon world right now, in the last 10 years has been a big movement to not make the hip angle as acute. The perception being that if that hip angle is too acute it impinges the athlete’s performance when they get to the run, and that was born by feedback from a lot of top athletes, I think. And that’s sort of trickled down and there are different ways you can make that hip angle less acute, and one of them is to slam your saddle forward, another is to put the rider on shorter cranks, or some combination of other things. So that’s one aspect, and then the other part I think, is that people are chasing aerodynamics, they’re chasing CDA in the road, and if you want to slam your bars low but you don’t have the hip mobility to handle that acute angle between the femur and the torso, then slam the saddle forward but a longer stem on. Of course, that changes your weight distribution over the bottom rack and the axle. So i’d like to know what you think about that trend right now?


Jason Williams  1:21:22

it’s a good one, it’s a really good point in question. The pandemic lockdown let me dig deep into this, so I’ve spent the last year really cracking into this concept. One of the benefits of the Retül data is that I have motion capture data of thousands of riders to look at, including hundreds of professional athletes, as well as everyday athletes that we see, you know in the world. So i’ll back up a little bit, and say probably some of this is a reaction from kind of Lemond era, you know, old school road racing when that that seat was back, that reach was long, and you know we look back at those positions, you know, in in footage these days and it’s like, “oh my god how could anybody ride that way,” so I think we came from a position that was really extreme in the other direction, and for me as a fitter, my entire career has a lot of the corrections have been, yeah trying to get people on top of the pedal and get them out of the backseat, and that’s kind of been a theme that I’ve seen, is like okay, people are on the bike and they’re in the back end and so we might bring them forward a little bit, to kind of a neutral knee over pedal spindle, right? I know that’s kind of an antiquated concept, but you know


Colby Pearce  1:22:38



Jason Williams  1:22:39

Getting them from an inch or two behind, at least on top of the pedal, was a huge benefit. Anecdotally, so many riders found benefit in that change going from behind the pedal to at least above the pedal with the knee and in a traditional sense.


Colby Pearce  1:22:52

I’m sorry to interrupt, but I definitely want to drop a link in the show notes to a really old school article on this, it’s written by Keith Bontrager, of yes Bontrager. And it’s called the K.O.P.S, that’s knee over pedal spindle, that’s the acronym, and he unpacks his philosophy on why knee over pedal spindles is a super arbitrary measurement, that has been used in bike fitting for years and years, and why he thinks is not relevant. So anyway, I want to put that in there so people can read that it’s a great piece of history. So please continue.


Jason Williams  1:23:23

No that’s great, I mean that K.O.P.S., knee over pedal spindle, kind of an analogue method with you know using the Plumb Line, right? Dropping a Plumb Bob from the knee, somewhere on the knee to somewhere on the pedal or crank, I think it’s a good it’s a good guide, but it’s not, you know, this kind of like get to the millimeter kind of target in any way. But in any case, to your point I guess I we’ve come from a place where a lot of athletes were riding behind the pedals, and so we’ve kind of come on top of the pedals, I think we made good strides there. I think you’re right in your observation that we do see a trend in elite athletes slamming forward with the saddle, you know, zero offset seat posts, and seat slam forward, I think you’re right about protecting the hip angle. The hip is a finite range of movement, right? You’re going to bump into the torso, you’re going to bump into the rib cage, right? So all riders have a finite range of motion when it comes to closing the hip, so one thing I was able to pull from the pro data, versus your everyday rider, or your average joe weekend athlete, is that even though they ride 130 mil stems, and they ride what we think is aggressive, they’re marginally more closed at the hip than you and I. So looking at the Retül data sets, we can say that, yes they are lower for aerodynamics for other factors, but they’re not that much more closed at the hip than your average rider. So, you know, there’s a number of ways that they can do that to maintain a relatively open hip or a not overly closed hip, you know, the ankle plays a role, right? The riders have to sort of manipulate the foot and ankle to clear the top of the pedal stroke, for a rider to maintain a hip closure, the ankle, and the saddle fore and aft, are ways that they can maintain a reasonable hip closure. So you’re right, there is a trend for sure in riders coming forward with the saddle, and I think it is to protect hip angle. But I think you right, aerodynamics is part of that calculus at the, at the professional level, but I also think, you know, for me, I’m nowhere near a professional athlete, but when I’m pushing hard, I want to get up on top of the pedals, and I sit forward on the saddle, and I think it’s acknowledging that that’s where I go when I pedal hard, and not to say that what I do in a bike has anything to do with other people, but I do think this tendency to shift forward and sit on the tip of the saddle when you’re giving it some gas is common. So let’s, you know, support the rider and get the saddle underneath them and let them be supported in a position that they want to push the pedals in.


Jason Williams  1:26:12

So what do you think of the potential compromises then, as you bring the saddle forward, I’m thinking specifically about muscle recruitment patterns, and also thinking about how much of the way that the torso is supported by the saddle.


Potential Compromises of Bringing Saddle Forward

Jason Williams  1:26:23

Right. You know, I mean, for us as fitters, we often think about, you know, what is the cost at the knee joint, right? Are we overloading the patellar tendon? Are we over stressing the knee joint? And, you know, when you talk about athletes that are highly tuned to tolerate that position, it might be more reasonable for an athlete who has no knee pain, has all the physio, the massage, the support to tolerate that position, they might be able to do that. But, you know, for you and I to jump on a bike and slam that seat all the way forward, there may be negative compromises at the knee joint, you know, at the back, pressure on the hands, and yeah, handling quality, if you think about the weight distribution on the bike to slam all the way forward and put all that weight on the front end, we are, probably pushing the bounds of what that bike was meant to handle as far as weight distribution and how the bike is going to behave with that shift in mass.


Colby Pearce  1:27:17

Yeah, and Happy talks about that, he is of the opinion that a lot of pros that have slammed themselves forward, now he’s getting a lot. His opinion is, they’re getting a lot more front wheel washouts, because for too much weight on the front wheel, and things are imbalanced. And that’s why we’re seeing these massive crashes in roundabouts and stuff. And like, it’d be really interesting to look at the data on that, you could probably characterize Grand Tour average speed, break stages down to terrain profiles, and then look at number of crashes in the last 20 years and correlate that, I bet you could look at that data, that’s probably researchable. I wonder if anyone’s done that, but and then look, you’d have to have some sort of baseline for seeing how much saddles have come forward, and that data is probably also accessible. I mean, you guys, Retül works with, I don’t know, a third of the Pro Peloton, I bet you update on at least I’m guessing, I don’t know, maybe more, but so you could look at that data in mind that too and do that correlation and see if there is an increase in that. And Happy and I concluded our podcast by saying, I am of the opinion, I hope that bike manufacturers do not start to shift the geometry of road bikes to ever, ever really steep C2 angles, and become triathlete bikes, to offset that, and allow riders to come more forward. There’s got to be I mean, if everyone’s using zero offset posts, and slamming their saddles all the way forward, I mean, you know, that the optimal place to clamp a saddle is not at the end of the rails one way or the other, because inevitably, you hit a big hole and something bad happened, the bolt breaks or rails bend, or whatever, then somebody gets skewered, that’s never a good scenario. So we want the saddle, we want the seat angle, seat tube angle of the bike to allow themselves to be climbed to the center of the rails, then, you know, because the saddle is a suspended object, people don’t maybe understand this, but it’s like a wheel, the base has tension, and that tension, it’s that’s why you can’t just put new saddle rails on yourself if they come off, which happens about once every Blue Moon, you have to have this massive machine that pulls the base over the rails and it’s sprung, and that’s what gives it a saddle, that kind of light suspension aspect to it, right? That tension in the base, it’s like a wheel, like spokes in a wheel. So when you come down hard, and that suspended surface, if you exceed the what I don’t know my engineering term, the something force tension, things brake. But so I’m hoping that while I want saddles to be clamped in the center of the rail, so that the suspended structure of the saddle can do its job and help the riders butt stay comfy over bumpy surfaces, I don’t really want bikes geometry to shift to reflect this trend because to me, this is a bit of a bell bottom trend, and I’ll just say from my perspective, I think we’re we’re potentially sacrificing some handling aspects of the bike, a bike could be re- engineered to handle, to offset that forward position. But from my perspective, you look in the gym, okay, you brought it up to just a minute ago, if someone’s doing a squat or a lunge, and their knee comes way out over the toe, the first thing we see is, in a squat, we see that they’re going to, by necessity, have spinal flexion, so they’re compromising the function their spine, that may or may not be the case on the bike. But we’re also increasing patellar shear force, so we’ve got to assume that with forward position, there’s probably a likely, a higher likelihood of anterior knee overuse injuries, most likely, and at what price, or at what benefit, it’s to reduce the hip angle. It’s a factor, but also when we shove the butt forward, we’re influencing muscle recruit patterns, and we’re putting the athlete into quad dominance. So from my perspective, when you slam the saddle forward, it doesn’t make a lot of sense, because if I were coaching someone to have ideal squat form in the gym, what does every strength conditioning coach do? They start you off with, for example, a wall squat, where you’re facing the wall, right? And your toes are three or four, maybe five inches away from the wall, and you squat down, and if you can do it, well, your butt pushes out from the wall and your chest doesn’t come into the wall, you don’t scrape your nose on that wall. That’s a simple bodyweight exercise that helps us define whether an athlete has the ability to hip hinge under load, and if you can’t do a wall squat without falling on your butt, then we know that you’ve got some hip hinge challenges. And when we do that wall squat, it really emphasizes the posterior chain function, that’s glutes, calves, glutes, and hamstrings, and how well they can move but also how well they can handle that tension, right? Under load. So when we do that wall squat, it tells us about how the athlete moves in space, and now we put them under in a squat rack loaded in a back squat position, and if we, let’s say we’re doing a four by twelve, with heavy weight, if I was a strength coach, and I saw that the last three reps, of every set, their knees were coming forward, and they were going less deep, that would be the equivalent of slamming the saddle forward on the bike. Because when you move forward on the saddle, you’re getting less knee extension, right? Because you’re, you’re assuming a saddle horizontal or close, you’re not moving that tangent to the circle, you’re moving in horizontal. So now I’ve gone to under extension, so I’m not using the muscles to their full range, but I’m also pushing the knees forward, increasing patellar shear, but I’m down regulating posterior chain recruitment. So I’m going from less glute to more quad, and I don’t this is, I would say a heated topic right now and in, it’s not heated at all in the gym, like any strength and conditioning coach who’s respectable that I’ve ever studied or, or worked with, would argue that we want to keep your butt back and have proper form during all those reps.


Colby Pearce  1:27:51

But it’s cycling for some reason, it’s acceptable to come forward over the bottom bracket and get on top of the pedals, as you described. And there are a lot of riders who ride this way. I’ve trained myself to not ride that way when I go hard, but maybe I’m just me, and there are I think there’s some athletes who can do that. And so, without going down too many more wormholes of fitting, and saddle choice, and all the other bits, it seems to me that the way to solve this problem is to keep the bike back, keep glute recruitment engaged, and shorten crank length. And so then when the crank is in the vertical position, obviously, we don’t have as acute of a hip angle, right? To me, that’s like the tidy solution, and in case people are wondering, there’s a mountain of science shows that crank length has very little to do with FTP and power output. There are limited applications where you do want a longer crank, but the short the cliff notes are, that Jim Martin’s done a lot of science on this, and please tell me if you agree or disagree with this, but the cliff notes are, if you’re a world tour level pros trying to win a stage in the Vuelta, or you’re across country mountain biker, you might have an argument to push the envelope on longer crank length. And the reason is that for those two rider examples, you’ve got scenarios where the rider runs out of gears, meaning they cannot shift, they’re in their lowest gear, and they’re going as hard as possible on a really steep grade at low cadence, and in those conditions, a long crank will help you. The problem is you have to carry around that long crank length and deal with that extra functional challenge of that super deep squat all the rest of the year, and for the vast majority of all athletes, you might think you’re gonna win a stage in the Vuelta, but sorry man, you probably not. Sorry, a lot of thoughts.


Colby Pearce  1:33:41

No, that’s good. Um, you know, the short crank length is is a good observation and I think that’s definitely something that is fun to test, in a fit session with an adjustable crank and actually drop the crank length. And you’re right, I mean, from my understanding, I haven’t gone super deep on the crank length topic, I’m aware of Jim Martin’s research to say that, basically, it doesn’t really matter, you know, like, if you with a bit of adaptation, we all can ride a good number of cranks. I do think, you know, biomechanically, there is kind of a crank length, that sort of within the bounds of what the body will react to well, but in general, for me as a fitter, shorter crank length, generally just have a benefit, like we said, to keep the hip angle open to not over flex the knee. So yeah, there is in a fit context, a lot of benefit to the shorter cranks.


Colby Pearce  1:35:40

Help keep the hips more stable.


Jason Williams  1:35:42



Colby Pearce  1:35:42

That’s what I’ve observed.


Jason Williams  1:35:42

Rarely, what I say during a fit, let’s put you on a long crank. I mean, that would be a real outlier scenario for me to say, let’s step you up.


Colby Pearce  1:35:50



Jason Williams  1:35:50

But there’s a number of cases in a fit scenario where I’d say, you know, taking it down two to five mil would really be a benefit for hips, for knees, otherwise.


How the Triathlon Community Broke Down Boundaries in Bike Fitting

Jason Williams  1:35:59

So yeah, I think that short crank is a consideration, for people going to extremes, I don’t know, as we, you know, I wouldn’t make a case to go too far, I’m probably conservative on on that front. So if it’s, you know, you’re on a 175, dropping a couple mil, probably would be a benefit, but I’m not necessarily one to say, “Oh, yeah, let’s take you to 160, and, you know, really push that bounds”. But, you know, in, especially in, we can give credit to the triathlon community for pushing those bounds, right? I mean, these are riders who are willing to experiment and have really led the way in testing super short cranks, and super forwars positions and trying it out, right? I mean, why not experiment and see if we can find benefit? So, you know, we definitely owe the traveling community for that willingness to experiment with some of these sort of fringy concepts that really, in some cases have benefited in some cases, it’s just an individual preference.


Colby Pearce  1:36:52

Yeah, well, I think that’s all for position, and that discussion is nuanced, and it’s got a lot just like anything, the deeper you dig into it, the more ramifications they’re are? Right?


Jason Williams  1:37:02

No, you’re right. I mean, it’s, uh, I guess, from my perspective, I can say, I can identify what the trend is, and then yeah, that’s where the discussion is, whether that’s, you know, good or bad, right? So, you know, again, like we talked about earlier, you know, there’s riders who distill a position based on their discipline and based on, you know, where they find benefit, right? So, you know, if a rider tries a position and the knees bother, they’re probably not gonna stay there, right? But does that mean you and I can ride that position Without our knees bothering? Maybe.


Colby Pearce  1:37:34

Maybe, maybe, maybe not. Right.


Jason Williams  1:37:36

So yeah, it’s an interesting question. But you know, I think if there’s benefit, whether it’s psychological, or, you know, physiological, riders are always going to chase after benefit. And so there’s, you know, in triathlon and road racing, mountain biking, and otherwise, there’s riders that are pushing those bounds to see if we can shake up the trends to find, you know, performance benefit, right? Everyone wants to find that .1%, that might give them that podium spot. So people are willing to push that bound to see if they can find that .1%.


Colby Pearce  1:38:11

Yeah, that’s a good point, I was listening to a podcast last night, it’s called, That Triathlon Show, or something like that. It’s quite a good pod, actually.


Psychology Plays a Big Role in Bike Fitting

Colby Pearce  1:38:22

And the guy’s a coach, he’s a, he’s a triathlon coach, he was talking about how a suggestion he had is, for during, I’m making a parallel here, in an annual program or annual plan, you might train your weakness, the farther you are from away from a race and then progress towards your strength, the closer you get. And he went so far as to suggest that there’s not a lot of data to support, training more of your weakness or more of your strength is that old saying, you know, train weakness race your strength, is there’s not a ton of data in any individual case to support that one may give you a better performance than the other, but there’s a benefit to the fact that in the months coming into your race, the last two months, for example, if you train more of your strength, you’re naturally going to have more success in your training efforts. So if you’re a threshold monster, you might, you know, work more on Vo2 early season, for example, and work more towards threshold as you get closer to your race, and that is just going to help sort of, put wind in your sails, we might say, to help you feel better, because you’re naturally good at that. And that’s going to give you confidence, and that confidence is going to help you kind of align towards your goal of that peak performance for your race. And so I think there are a lot of confounding variables in human performance in psychology, the athlete and how it plays out. If someone perceives that putting a 140 stem on, and slamming their saddle forward is going to make them super aero, and every time they get on the flats, they feel like they’re crushing people because of that 140 stem, they look down and see that might be worth as much or more than any other positional philosophy or change that we give them, right? So it’s about belief and intent as much as it is the actual outcome, in some cases. I’m not saying that you can put any rider in any position and have them believe that because they’re shaped like a wider cheese, they’re going to win bike races, but psychology plays a lot, right? It’s the placebo effect.


Jason Williams  1:40:13

No, I think you’re right, like the psychological impact of bike fitting and positioning and tuning. Even if we go through a couple hour, three, four, six-hour session, and we don’t change anything, but that rider knows now, A, they’re confident that their position is good.


Colby Pearce  1:40:28



Jason Williams  1:40:28

They leave that session, we didn’t change a thing, but we looked at everything.


Colby Pearce  1:40:33

Looked under all the rocks.


Jason Williams  1:40:33

Answered all of their questions, we explored all of the variables.


Colby Pearce  1:40:37



Jason Williams  1:40:38

They can leave their being like, “that was so worth it, because now I know, my position is good,” I can just go hammer the pedals. And so I think that’s kind of this, you know, the trap that a lot of fitters can get into is like, get a rider in and like feel like they have to make a big change, it’s such a trap to think that that making a change is the point of the session, the point of the session is to evaluate the rider, work with the rider based on their variables, and if there’s no reason for change, and we can’t find any benefit to change, then that’s still a great result to confirm your position is fantastic.


Colby Pearce  1:41:12

That’s an excellent point.


Jason Williams  1:41:13

The other thing that you keyed in on there that I really like is, is you know, I always tell riders at the end of the session, like the pedaling muscles, you know, riding form will come naturally. Where are we now, we’re in in March, right? So now is not the time to worry too much about the big power and the all the riding stuff, come June and July, that’s all going to sort itself out in a way, you’re going to be riding, and that’s going to sort itself out. Now is the time for the yoga, and the Pilates, and the strength training, and the stuff that you kind of have to engage with, right? The things that you have to, like you said, your weakness, right? Training to your weakness, so if during the fit, we identify some flexibility concerns, some strength concerns, some core strength variables that we want to work on, that’s the stuff to sort of prioritize and focus on. Your pedaling muscles, your pedaling fitness is just going to come, you’re going to ride yourself into that fitness as you adapt to the position and ride. But where we have to motivate to make a difference is in the off-bike training and doing some of that kind of core strength and the kind of off bike stability work that we all would benefit from.


Colby Pearce  1:42:20



Jason Williams  1:42:20

If we take the time and commit to really engage with that.


Colby Pearce  1:42:23



Jason Williams  1:42:24

I do believe that the ride fitness just, it will naturally come on its own.


Colby Pearce  1:42:29

Jason, thank you so much for making time to come in today. It was great to talk shop with you, dork out on all things fitting, I really appreciate it. Um, if you wouldn’t mind, tell riders, where people can find out more about you.


Jason Williams  1:42:42

Sure. I work at Retül Headquarters in Boulder, Colorado, or on Airport Road in Boulder. It’s a specialized experience center, we have a demo facility with a number of great specialized demo bikes, and we have our fifth studios in place there.


Colby Pearce  1:43:01

We’ll put a link to the experience center in the show notes so people can chase you down there.


Colby Pearce  1:43:09

Attention space monkeys, public service announcement, really, technically, it’s a disclaimer, you already know this, but I’m going to remind you that I’m not a lawyer, and I’m not a doctor, so don’t think anything on this podcast to constitute lawyerly or doctorly advice. I don’t play either of those characters on the internet. Also, we talk about lots of things, and that means we have opinions, my guest’s opinions are not necessarily reflective of the opinions of anyone who is employed by or works at Fast Talk Labs. Also, if you want to reach out and talk to me about things, feedback on the podcast, good, bad or otherwise, you may do so at the following email address info@cyclinginalignment.com. That’s all spelled just like it sounds, which again is self-evident. Gratitude.