Trail, Rake, and Flop—Bike Design with Lennard Zinn

Lennard Zinn joins us today to delve into why bike design elements—like fork offset, trail, and head tube angle—have a bigger impact on a bike’s performance and ride quality than frame material, or any of the things we focus on when checking out what our friends are riding.

So, you think you know bicycles? Well, think again. Today we’re sitting down with a legend of the cycling industry to talk about a variety of factors in frame design that most cyclists have never heard of. Yet these design elements—things like fork offset, trail, and head tube angle—have a bigger impact on a bike’s performance and ride quality than frame material, or any of the things we focus on when checking out what our friends are riding.

Our guest today is longtime VeloNews contributor Lennard Zinn. Author of the definitive books on bicycle maintenance, “Zinn and the Art of Road Bike Maintenance” and “Zinn and the Art of Mountain Bike Maintenance,” among other titles, Zinn has spent the past 37 years building custom bikes and studying the physics of bicycle design. Incidentally, it all started with his college thesis on building an un-rideable bike.

So, today, we’ll delve into:

  • The concepts of fork rake, head-tube angle, and trail, among others, and why each is a crucial element of bike design.
  • How these factors act together to make the bike more or less stable, and why greater stability may not be what you’re looking for.
  • The effects of wheel flop and how it impacts your ability to corner, including an explanation of counter-steering and when you’d want to use it.
  • How understanding rake, trail, and flop can have a significant impact on your performance, as well as how you can put it to good use in selecting the right bike for you.
  • The evolution of bike design and how it has been influenced by both fashion and performance.
  • And finally, some guidelines on selecting your next bike and how to get the ride experience you want.

So, have you brushed up on your physics? Are you prepared to learn how a bicycle really works? Let’s make you fast!

Primary Guests
Lennard Zinn: Tech guru and author

Episode Transcript



Welcome to fast all the news podcast everything you need to know to run.


Chris Case  00:14

Hello and welcome to Fast Talk. I’m your host Chris case managing editor of velonews joined by the archetype of the retro grouch, Coach Trevor Connor. So you think you know bicycles? Well, think again. Today we’re sitting down with a legend of the cycling industry to talk about a variety of factors in frame design that most cyclists have never even heard of. Yet these design elements, things like fork offset trail head tube angle, have a bigger impact on a bikes performance and ride quality than frame material or any of the things we focus on when checking out what our friends are writing. Our guest today is longtime villain News contributor, Leonard’s in author of the definitive books on bicycle maintenance. Zen in the art of road bike maintenance, Zen and the Art of mountain bike means, among other titles, Zinn has spent the past 37 years building custom bikes and studying the physics of bicycle design. Incidentally, it all started with his college thesis on building an unraidable bike. We’ll hear more about that in a moment. But today’s program will delve into the following things, the concepts of fork, rake, head, tube, angle, and trail, among others, and why each is a crucial element of bike design. how each of these factors acts together to make the bike more or less stable, and why greater stability may not be what you’re looking for, the effects of wheel flop, and how it impacts your ability to corner, including an explanation of counter steering and why you’d want to use it. How understanding rake trail and flop can have a significant impact on your performance, as well as how you can put it to good use and selecting the right bike for you. The evolution of bike design and how it has been influenced by both fashion and performance. And finally, some guidelines in selecting your next bike and how to get the ride experience you want. So have you brushed up on physics? Are you prepared to learn how a bicycle really works? Let’s make you fast.


Chris Case  02:31

Well, we’re sitting down with the legend himself, Leonard Zinn, longtime contributor to fella news, staff member at one point, maybe and



actually never had a full time permanent job in my entire life.


Chris Case  02:46

I mean, owning a business billion bikes is kind of a full time job, but it is sort of a



real job. It’s like when Bruce Springsteen says, You know, I, I worked on a roofing crew, until I made enough money to buy my first guitar and then I quit and that was the last time I’ve ever had real work in my life. He kind of feel that way.


Chris Case  03:05

You are a rock star, after all.


Trevor Connor  03:09

So to start out here, I’m looking at our agenda and I’ll admit as the resident retro grouch and seen a whole bunch of terms that I’m pretty unfamiliar with, and I know we’re gonna do a pretty deep dive into each of these. But maybe we can start out with just a 32nd definition of each. So we have for trail, head angle, fork, rake and wheel flop.



So, fork rake can also be expressed as fork offset is the perpendicular offset of the position of the front hub, the center of the front hub relative to the steering axis. So forks in the past always were curved. And this rake was like the curve of a rake. savviest too and it was obvious that if it had a lot of bend, there was a lot of fork rake now forks, the fork legs tend to be straight, but they’re angled at the fork crown, or like a like a suspension fork off in the crown will be will be angled forward each, they won’t be a flat crown it’ll be it’ll be sort of a V shaped angle forward, and then you’ll have these straight legs and then you’ll also often have the dropouts sticking out projecting forward from from those so all those things combined give you the the offset of the center of the front hub relative to the to the steering axis. Then head angle is the angle of the of the steering axis relative to horizontal. So the head tube of the bike if you were to put up put a protractor on it and and compare it with the


Chris Case  04:52

there’s probably some people out there that have no idea what a protractor



well anyway if you if you can use a Perhaps Yes, okay, well, if you if you take a ruler along the head, angle the bike and you and you, if you take the ruler all the way down to the ground, and then you measure the angle between the ground and that ruler, so it’s always the acute angle you’re interested in, I mean, obviously, say, say you’ve got a 70 degree angle, head angle, well, then the complement of that is also the angle of that of that steering axis relative The ground is 110 degrees. So you know, you don’t ever express the head angle is 110 degrees, you’d express it as the 70 degrees as the acute angle. So then the fork trail is the distance between the steering axis intersect with the ground and the tire contact patch on the ground. So if you follow this, the line of the steering axis all the way out to where he touches the ground, and you mark that point, and then you measure back to the center of where the tire is touching the ground, that distance is trail or fork trail. And it’s related to not only the head angle, you can see as as we change that head angle, we spoke about how that changes where the steering axis intersects the ground. And you can see that as you decrease the head angle, the the steer the axis, the intersection point moves further forward. So that would increase the force trail, and vice versa. And also, you can see the fork offset as the fork, fork offset gets greater than that moves the contact patch of the tire forward relative to the steering axis intersect. And so that decreases the fork trail.


Chris Case  06:45

But that brings us to a good point your previous sort of job working for somebody else was with Tom Ritchie. Yeah, 30. How many years ago was that?



1981 and 82. So


Chris Case  07:03

3637 years ago, and that’s where we want to go to because that explains a lot of your experience with frame design. That’s where you sort of learned the craft.



That’s where I learned the craft, about building bikes. But frame design was actually something that I studied quite a bit before that, because my degree is in physics, and I did my senior seminar on the stability of a bicycle. And I did a couple of things to try and figure that out. One was,


Chris Case  07:31

that seems so simple, but it’s not. No. That’s what we’re gonna do,



like physicists have argued for years about what makes a bicycle stay upright, is it that it’s a very skinny steamroller, or it’s the gyroscopic effect of the wheels. Or, you know, there’s been a whole bunch of theories. And at the time, I learned Fortran. In order to do this computer model of bicycle design. I don’t think I’ve used Fortran really, since


Chris Case  08:05

I’ve never even heard a Fortran



language from back in the day. And I tried to build an unraidable bicycle out of an old bikes from from Disabled American Veterans in Colorado Springs, building an


Chris Case  08:21

unrideable bicycle. Now that sounds like a fun senior project



was and so and from that, you can then learn what it is that makes a bicycle stable, what makes it stand up, because it’s not that easy. You’ve after I discovered after a while that, you know, you as a rider have so much ability to keep the bike upright, that you end up having to take the bike out of the out of the equation, and I just piled it up with weights, pushed it across the parking lot is what I ended up ended up doing in order to test these things. But other than if you set something up in the bike, so it works the absolute opposite of how like, I don’t know if you ever seen that video of the guy where he somehow turns the steering system around, right? heard about this? Yeah, and it’s just crazy. So you turn the handlebar one way and the wheel goes the opposite way of what you and and, and people are like, oh, that’d be no problem, you know, and good riders try it and they’re just constantly crashing and then and then he goes, takes it to the train station Amsterdam and has people come Hey, you want to ride this bike? But you can’t ride this bike and then ride the bike. Right and and then when he then he’s now finally learned how to ride this thing. And then he gets on a normal bike and then he can stay. Yes, so so there’s the human has a whole lot to do with it. But in any case, what I really discovered was first of all, how incredibly stable Harley Hogg is that that looks to me like a crazy contraption, you know with a super super Long, long fork that sticks way, way, way out in front. But those guys are able to just sit there with no hands and ride that thing at really high speeds. It’s just totally on maneuverable. But and so that’s, that’s the thing that, that you have to balance when you’re designing a bike is you, you don’t want it to be too stable to be steered, which is kind of what a Harley Hogg is right? And you you from a performance perspective on a bicycle, you wouldn’t want to do that, because you just can’t, unless you’re riding it across the country. Right? Yeah, rode the whole way. Yeah, it’s not what you want. So you, you push the bike toward instability when you do this. But the, the way I built the bike that that would not stay up, I like one way to make a bike that is incredibly stable, where you just pile a bunch of weight on it, and you push it across a parking lot. And it’s so stable, that you can keep running along and banging, banging the handlebars or banging the seat from the side as you run along. And it just keeps straightening up, straightening up and straightening up. And until it finally runs out of momentum, and then just kind of reels lazy swings back and forth, and back and forth. And then


Chris Case  11:19

and what’s different about that,



that bike, all I did was took one of these bikes from Disabled American Veterans and turn the foreground backwards. So I have negative fork rake, and obviously turn the handlebar around them the other way. And what the, what that does, giving a negative for Crake is it makes the fork trail very big. So for trail is this distance measured on the road as you’re on the surface that the bike is sitting on. And it’s the distance between where the steering axis, so you draw a line through the, through the center of the head to through where the fork goes through the headset bearings, and you just continue that until it hits the ground. That’s the intersection the steering axis with the ground, and then there’s the contact point of the tire with the ground. And the distance between those is the fork trail, or trail. And the bigger that is, the more stable The bike is. And so going back to that Harley



analogy, going



back to the Harley analogy, what you have is, is this super, super shallow head angle, and, and maybe you’ve got a little bit of fork rake to it, but it’s almost irrelevant, because the the head angle is so low and and yeah, if you project that line straight down that fork way, way out way out in front end roadway on front of the bike, and then measure from their back to the contact patch of that front wheel. It’s it’s a long distance and that that word trail is actually a very good word to use for this because even though the bicycle looks like the front wheel is ahead of it on the front end of it, it’s actually trailing the bicycle. And the analogy is if you go to a grocery store, and you pull a grocery cart out of the rack, and when you pull it back, the little casters on the front flip around, so that they’re now they those have little forks on them, a little bit of fork rake little bend to them, or curve to them. And when you pull back on the, on the cart, the wheels flip around so that they’re trailing the cart, and you pull it back. And then as soon as you push it forward, they flip around the other way. So they’re now again, they’re in each case, they’re trailing the steering axis there, the steering axis is vertical on the on the shopping cart, it’s just a, you know, a caster that sticks straight up into these holes. And in this bottom of the shopping cart, and the wheels will always flip around backwards to trail that that steering axis. And if you get one every now and then you get one that’s a really crazy behaving card. And it’s because generally, the shaft that the caster turns on is is like frozen, so it can’t spin around freely. And then the wheels or, or one wheel is facing forward when it should have flipped around back. And the thing is just it’s a wobbly thing rolling around the grocery store.


Chris Case  14:22

I was gonna say, even though you’ve explained that I bet there’s some people out there that are like there’s no way that the wheel is up front. How is it possible that it’s trailing the bike



so another another way to think about this is when you go to push your bike along, you can push a bike along by grabbing the saddle and just everybody sort of has had that experience you can walk along and you can maneuver it through a crowd and everything holding on to the south, tipping it side side, right know how it’s gonna behave. If you try and do the other way around where the rear wheel is visually trailing the front wheel and you turn it around and you push it, you push it from the saddle with the rear wheel first. It’ll you can’t control it, the front wheel is doing all sorts of crazy stuff because it is not actually trailing the bike at that point. So the way for instance, to make the unraidable bike a bike that where you’d pile it up with weight, so that it would just fall over almost immediately is to make it where the front wheel is literally not trailing the bike where you have where you have negative fork trail. And so that that means that that the steering axis intersects the road behind the contact patch of the tire.


Trevor Connor  15:33

So you’re essentially doing what you’re describing with a grocery cart, where you’re setting it up so that the wheel won’t turn around. And now you’re you’re pushing that wheel under the



Oh, yeah, exactly. So the way to do that, like the way to do it with a with a old bike from Disabled American Veterans is to take pieces of steel plate, and drill some holes in them and make the fork rake super, super long. So just bolt those to the fork and then stick those straight out ahead and, and bolt those to the wheel so that the fork has this incredible amount of fork rake. In other words for fork rake is fork offset. So that’s the that’s the distance that the front hub is forward of the axis of the fork. And so that’s a perpendicular distance forward from the steering axis of the of the front hub. So


Trevor Connor  16:23

essentially the the curve and the fork is this Yeah,



so but now forks, of course are straight and people think oh, that means it doesn’t have any rake. No, it means that the rake is built in at the crown, it’s the legs are angled forward instead of being curved. So anyway, if you have this fork with this huge amount of fork rake, so I think I had mine, I had like two feet of fork rake fork offset to it. And then you pile it up with bricks, and you push it, it just, it just falls over immediately. You can’t You can’t just can’t get it to get going at all. It’s like trying to push your bat bike backwards. And it may seem counterintuitive, because people often think of especially these are in the old days more than the touring bikes had a lot of curve to the fork, bend to the fork. Yeah. And then you’d compare that with a with a criterium bike and it looked like it was you know, not much fork rake and pretty, pretty straightforward. And especially a track bike track bike is deceptive. Because a track bike, the track basically makes it so that your drive riding straight the whole time. So a track bike, you actually want to be extremely stable. But that’s not the case with a criterium bike criterion bike, you want to be quite maneuverable. So you want it to to you want to push that bike much more toward the instability side. Also, the wheel diameter plays a role that that if you have all the same, this same geometry of the same amount of fork offset in the same head angle, but you’re very small wheel, the steering axis line won’t be able to diverge very much. So the tire contact patch will be quite a bit closer to the steering axis intersect, the smaller that wheel is and then obviously the the bigger it is so. So those also need to be taken into account when you’re looking at, for instance, a little kid’s bike with 12 inch wheels versus adult bike with a toy like a 29. You can’t expect to have similar handling characteristics with the same fork head angle and fork rake on those two bikes because the wheel diameter plays such a huge role.


Trevor Connor  18:37

Now So a question I was going to ask you about bikes. And I’m going to say I’m coming at this from the position of I’m the guy who picks his bike by going into the bike shop and basically saying what’s cheap, and nobody will be caught dead on and I’ll buy it. So I don’t ever consider these things, which I really should. And I’ve certainly gotten on bikes before and even though I’m always guys as a frame as a frame, I get on some bikes and go, I can’t get this damn thing around a corner. So it seems like in different situations you want more or less fork rake. So I guess what would be the situations where you’d want more? And what would be the situations you’d want less? And more importantly, is that something that you can accomplish this by replacing the fork? Or is that in the whole frame design?


Chris Case  19:20

Correct me if I’m wrong, but it’s the interplay of all of these things that makes the complete package and makes a bike. If it’s a bike that’s built for criteriums it’s one, not just one of those things that makes it great at that at what it’s intended for. And likewise with the touring bike on the other end of the spectrum.



Yeah, that’s, that’s correct. So earlier, I was just talking about changing the fork rake because I had an existing bike with an existing heading or an existing size wheel, but the fork trail which is the thing that you’re really interested in this trail distance, that the greater that is the more stability you have, that is a function The diameter of the wheel, the head angle, and the fork offset or fork rake, so whatever so so it’s all of those combined. So So yes, if you have an existing bike and you and you want to change its handling characteristics, you can’t realistically change the wheel diameter, I guess now with this brakes, you sort of can but but you generally can’t change the wheel diameter, and each can’t change the head angle, the one thing you can do is change the fork. So when earlier I mentioned, if you looked at a criterium bike compared to an old school, touring bike, and you’d say, Oh, well, you know that, that’s got a much straighter fork. And and and you know that a criterium bike is more maneuverable than the touring bike. Well, the criterion bike also has a much steeper head angle, and that that’s what then you can imagine, as the head angle get steeper, that brings that intersection point of the steering axis with the ground, it brings it back further, of course, it also brings the wheel back as well. But then that negates having less for Craig, if you if you steepen up the heading a lot in the touring bike would sort of be the opposite. Yes, maybe it has a lot of fork rake, but it’s also got a really shallow head angle. So those two things kind of counteract each other, and you and you can still have a fair amount of fork for trail with it. Now, people also have had the experience I think of of having a bike that they lean it over, they’re just walking along with his bike standing still, and you lean it over, and the wheel flops very strongly out of the plane of the bicycle flops inward. And one might assume that boy that just flops a lot that would be unstable, I think that would be somebody might write realistically think that it’s quite the opposite, you can define that, that we’ll flop. And that will flop is the wheel wants to flop more because any object is trying to reduce its potential energy at any given time. So so when you lean the bike over, if the bike can drop its potential energy more drop its center of gravity more it will do so and and and so if the geometry is such that the front that the front hub can drop down more by flipping by flopping inward more than it will do that. And the way a super stable bike achieves its stability is because every time the bike leans over the wheel flaps inward, super strongly to get the contact patches, the two contact patches, the front and rear tire to get them under the rider really quickly. So more wheel flop actually means more stability. And those guys with those Harley hogs, you can bet that those guys are gonna have some massive kind of kickstand setup on that bike. Because you know, if you, if you let it lean over a little bit, that wheels just gonna flop over and things are going to want to fall right all right over and you know that that’s a very stable bite.


Trevor Connor  23:04

So I’m imagining an example of this or more the opposite. I remember I flew to a race and my team was going out for a spin the first day there and I got there a little later them so I have put my bike together really, really fast and was stressed. And so when I was putting the the handlebars on it, just crank the down way too much. And quickly tighten up the bolts got in the bike and went out in the road. And I cranked it down so much the handlebars wouldn’t turn very easily at all, they were just kind of stuck in a straight



headset bearings were bound up.


Trevor Connor  23:37

Yeah, I probably destroyed my bearings doing it. And I noticed, I mean, I almost crashed a few times on those rides. Because if I tried to lean you have that expectation that the wheels gonna turn and because I was cranked down the wheel was being forced to stay straight. And then instead of turning the bike was just falling to the side. And I had to quickly correct. So that’s so you’re saying this wheel flop is kind of the opposite of that?



Yeah, yeah. So the wheel flop is what allows you for instance, when you ride your bike with no hands and you especially as you get to slower and slower speeds, and you lean a little bit and the wheel turns into the direction of you have your lean to get the wheel wheels back underneath you and it wants to that’s the position of stability is to have the wheel contact patches underneath the mass of the rider and then as when you’re making a big arc in turn, then the more stable the bike has a more it’s gonna turn into the turn as you lean it over and and and have that have that mass underneath. I mean have that the contact patches underneath the mass.


Trevor Connor  24:42

So you throw out a lot of technical terms, but it sounds like these factors all make a huge difference on the ride experience the the handling of the bike, I mean, these are really important things to be considering that probably a lot of us don’t even know about.



Yes, that is certainly the case.


Chris Case  24:59

You Yeah, I think it’s complex when you talk about all of these things, because there is a relationship between all of them, if you change one, it can change another thing and it can change your bikes riding characteristics completely, you could get it completely wrong if one of these things was not dialed in relative to the others said,



Yes, that’s, that’s correct. And there is also another input, and that’s the position of the riders weight relative to the wheels. So you can imagine that the same bike would handle quite a bit differently if the say that, see this push way, way, way back and the stem is shortened way, way up, even though the person’s reach from the saddle of the bar might be the same. He’s got a lot less weight on the front wheel a lot more on the rear wheel in that situation than if the reverse were that were the case and see were pushed way way forward a super long stem. Those will also play a role and and and a person as they get more more used to different bikes and, and, and what what their preferences are, they’ll often also tend to gravitate toward one way or the other. You see, like the current fashion with mountain bikes these days is, is incredibly shallow head angles, and super, super short stems, slacker


Chris Case  26:20

head tubes, they call it



Yeah, slacker head to the fork rate doesn’t tend to change that much the fork offset, because these are basically the suspension fork, there’s not a whole lot of variation that you see in the amount of fork offset. But this head angle changes a lot. And then and then the handlebars are getting longer and longer and longer. And you have much more leverage with these longer longer handlebars and then decreasing the stem length actually increases that leverage because it’s not, you know, less of a decrease in in the same movement of one hand is going to rotate it more the shorter the stem is than if it’s if you got a longer standard. So that’s like this


Chris Case  27:09

makes for more nimble, but I mean it it reacts



faster. Exactly, it makes the bike more nimble when you when you’ve got an extremely stable bike because you made this super super shallow heading right, which which gave it a whole ton of fork trail. And then by increasing this leverage that the rider has on the front wheel, then he then he can overcome that instability.


Chris Case  27:31

How does an understanding of some of the technical stuff in this episode for great trail head tube angle? How does that help a rider either become faster, more skilled, or even on the sort of on the commercial side of things, avoid being duped in a sense by some marketing claims by a company out there? So three, three distinct questions, I guess in one right there?



Well, for sure, I think if you think of a top motorcycle riders, for instance, top Moto, motocross, ride, motocross, Moto, gP gP Riders on the road, you can bet that those guys really understand the handling of the bike, what the bike is going to do, because it’s a much heavier thing, then then a bicycle that we pedal, and if they’re not working with the bike, and they’re making these turns that you know, I don’t know, but it’s ridiculous speeds, hundred 50 miles an hour or something, I don’t know. But but they’re turning at crazy speeds. And they’re getting it lean way, way, way over. Well. So this, this function of we’ll flop where you were the we lean the bike, and the wheel flops into that direction and lean quite a bit further than wheel turns into the into the turn that is intended. That’s the natural stability of the bike. And what that does, for instance, if you’re pushing pushing a bike along with just a pile of bricks on it, and and you bang on the handlebar something so that it liens are bang on the saddle, so it liens, what it will do is the wheel will turn quickly into the direction of the lien, and it will get the wheels back underneath the weight and then it’ll straighten up correct itself. Yeah, so but that’s the opposite of holding a deep lien like a Moto GP rider wants that guy wants to be in that lane, the bike stability wants to straighten it up the bike stability, if he just let the bike do it on its own, he leans it and the bike would get the wheel back underneath him and it would straighten back up and he would go straight across the field. He wants to if he wants to do that turn at that kind of speed. He has to hold it down into the into that lien


Chris Case  29:54

so it’s an intentional instability. Yeah, the



designers. Exactly. Yeah.


Trevor Connor  30:00

This is something I’m constantly telling new athletes and I’m teaching them how to corner is because it’s such a strange concept that when you’re going through a turn, a well designed bike actually wants to go back up, right, it wants to go straight. And actually, you have to force the bike over, yes, you’re fighting to push the bike down not to keep it from crashing. That’s right.



So so if you look at the Moto GP rider, you’ll see the guy lean way over. But if you look at the at him, his inside arm will be much straighter than his outside arm. And what that does is that he’s trying to it’s called countersteering, he’s trying to steer the opposite direction of what the what the bike wants to do, the bike wants to flop that, that wheel into the turn, and he wants to push it away from the turn. So he’s trying to push the the contact patch to the front tire out from underneath him. And then as long as he does that, then the centripetal force of him going into the turn, the only way to, to maintain that arc is for the the lean to get deeper and deeper. And so the more he pushes the wheel out from underneath him by pushing his inside arm forward and pulling in with his outside arm, turning, essentially turning the front wheel the opposite direction of the turn that he’s going into. The more he does that, the more it forces the bike into a lean. And so it is extremely useful to for the rider to understand that, I think if you ask most riders, and in fact, if you ask most riders, how do you get your bike to lean in return while you steer into the turn? And it’s not true here?


Trevor Connor  31:45

all the time? Don’t they’re always like, should you turn the handlebars? I’m like, No, no, don’t think about turning the handlebars.



Yeah. But once you understand this, then you can think about turning the handlebars except turning at the opposite direction


Chris Case  31:56

of what you think. Not aggressively. Yeah, it’s a so these are, these are subtle movements that we’re talking about. They’re subtle



movements, you can be sure that that foveon consolata. And, and and Peter Saigon, when they avoided that crash in the end of Milan, San Remo when when govia came down a couple of years, right? They’re going at high speed. Those guys did not do a gentle shuttle movement. They counter steered strongly and heavily and quickly. And that’s how they got around. And a lot of other people didn’t, they crashed into them because they didn’t have those kind of families skills. And those guys do understand, even though they might be able to not be able to verbalize it. They do understand how how the bike handles and I think, you know, Peter Sagan is a perfect example. He knows exactly where his bike is and what it what it needs to do at any point.


Chris Case  32:50

Understanding the geometry certainly helps you improve faster. At some point it becomes innate, you know, you’re you’re acting on instinct. But certainly knowing how the the frame design and the geometry there have plays a role in how a bike maneuvers is is a definitely a helpful skill.



Yeah, that’s that’s really true. But even people have been riding along time will find themselves in a situation where they say they go into a switchback on a downhill descent. And I guess descents always hard downhill. So they go into a switch back on a descent, and they think they’ve got the angle setup, right. And they’re, you know, starting from the opposite side and cutting in toward the, toward the apex and swinging out to the outside. And any number of things could happen, a car could be coming in, they suddenly have to make a correction of gravel or gravel that they see on the off squirrel



runs in front of you.



Yeah, or it’s an unfamiliar turn and and it turns out, that tightens up more, and they’ll be going in and they’ll suddenly realize, Oh, my gosh, my trajectory is taking me off the edge of the road on the other end. So their reaction reaction will be to put the brakes on and slow down. Which stance stands the bike up more, which continues them on this ride trajectory, what they really need to do is to be able to suddenly lean the bike deeper into the turn. And if they don’t understand how the bike works, then they won’t necessarily do that correction where they push with their inside arm pull in with their outside arm and force the bike into a lane and tighten up the tighten up the the radius of curvature. And so even though they’re like God, I’m slowing down, I’m slowing down, I’m going so slow, yet they’re still, you know, creeping along the edge of the guardrail, you know, no, they’re going ridiculously slow and they’re like this shouldn’t be I mean, what’s going on? And that’s, that’s the reason that all the bikes natural, natural self writing abilities are going to keep doing that are going to keep making it A straighter line and keep straightening it up more. And unless you understand that and you counteract it intentionally,


Trevor Connor  35:08

you’ll have that problem. This is one of the first rules of cornering, especially under descent is if you’re going to slow it down, do all your slowing before you hit the turn. Yeah. And then you should not be touching your brakes in that turn. And if you take the wrong line, if you have too much speed, it’s your last step should be to hit the brakes, you should first be, as you said, really trying to force that counter steer.



That’s right. But sometimes you do have to hit the brakes in the turn. And you still don’t want to go off the road. And so then your only way to end up getting through the turn is as you’re braking to countersteer. You know, and an example might also be when I was when I was on national cycling team, there was a, there was a book that was very, very famous about kind of everything about what you’d want to know to be a bike racer. And I know it was done by the Schwinn Wolverine club, somebody in the Schwinn Wolverine Club, which was very, very strong club in the 70s in Michigan, and produced a lot of great writers Tom Schuler among them. And Jeff Pierce, I think, too, and, but one of the things that said when it was talking about how to handle a bike, it was it literally in that chapter, he discussed how, you know, I used to think, something, whatever I thought the guy said, about how bike handle until I went and watched a Belgian car mass, you know, and these guys were doing these amazing things. And it was, you know, terrible conditions and slippery road and miserable weather. And, and what they were doing was when they come into a turn, they’d, they shift their weight way to the inside off the inside of the saddle, and then they, and then they reach to the outside. And they really steer where they’re where they’re, they’re pulling the inside arm in, and they’re pushing the outside arm out, which we just discussed, countersteering, that’s exactly the opposite of what you do. countersteering, where you get the butt on the saddle, firmly waited on the saddle, you push your inside arm forward, you pull your outside arm in? Well, the point is, what those guys were doing is they’re riding on a slippery, wet surface. And when you’re on a slippery wet surface, you want to have the bike as upright as it can be yet, you still got to get around the turn. Well, the way to get around a turn by keeping the bike upright is to actually enhance the bikes, the bikes, natural stability, which what’s the bike wants to do is, is turn deeply into the corner, turn sharply into the corner and stand the bike back up. And so that’s what those guys were doing.


Chris Case  37:40

You’ll see that in cyclocross, sometimes I think Yes, exactly. Well,



it’s and so so a good skilled rider will naturally make that correction on slip return, they’ll do that. And then on a dry turn, he’ll be countersteering. And, and won’t even necessarily think about it. But that’s, that’s what will be happening. But to have a book that prescribe This is how you turn a bike, when even in the description. He talked about how it was in terrible weather conditions


Chris Case  38:07

that he was watching is everything.



Yeah, but somehow he then extrapolated that to this is what you do. This is how you handle the bike like a Belgian, you know, you and and it was terrible advice. And people following that advice. If they continue to follow that advice, they would have gravitated toward a different kind of bike and different bike geometry because that, that advice is terrible advice. For riding on a dry, dry surface, right want to buy, you’d want to have a bike that was that was made that less of a problem than you were that you were turning it that way. Mm hmm.


Chris Case  38:44

So the second part of my question was, and it’s perhaps complex, but how does somebody use this knowledge that they’re going to gain in this episode, to make better purchasing decisions so that they don’t get duped as duped is a strong word, but there are marketing claims out there about bikes and how they’ll handle based on this and that and how does this knowledge help them from falling into any traps?



Well, it can help them a lot. One thing I think it’s important to understand what your purposes for the bike are, what you’re going to do with the bike. So I’ve been building bikes for 37 years and, and over that time, I’ve had customers who went from being pretty fit, strong performance minded riders to being much slower guy and in their 40s is now in his 70s, right? And some of these things that I’ve been talking about, we’ll flop and for trail, you want different things out of the bike depending on that. So it talked about how a lot of wheel flop is what you get with a very stable bike. And you would think that as you get older and older and you ride slower and slower, you want more Stable bike ride, it’s actually quite the opposite, because you’re riding quite a bit slower. And that means that as you lean back and forth while you’re say you’re weaving your way up a climb or you while you’re weaving your way up a climb, or you’re going, you’re going slowly out of the saddle, the front wheel is going to snake around more in the more we’ll flop it has and it’s going to be uncomfortable that won’t happen at higher speed. You know, you don’t get somebody racing Perry Bay at breakneck speed over all these bumps worrying too much about wheel flop, because they’re just, you’re overriding it with their speed. But at a slow speed. Yeah, it’s an issue, you actually want a less stable bike. And and the way you would achieve that would be reducing the fork trail that also can explain touring bike for an old guy, how it has a lot of fork rake, and we’ve just been discussing, if you left everything else the same, and you increase the fork rake, that decreases the bike stability, because it decreases the fork trail, well, it also decreases the wheel flop. And it can also be a benefit for the for the tourists because not only are they riding slower, they also have weight on the bike, right? They lean the bike over if the wheel flops less out of the lean, and they’re not going to have less trouble even just leaning it up against the railing when they stopped for lunch or what Right. Right. And, and so this understanding can definitely help when you’re making a purchase. And if you if you have some experience, if you can go back with you know, now all of the geometry of every bike that you could buy is online, you can look it up and and certainly they’ll give you the you’ll know the fort. I mean, excuse me, you’ll know the wheel diameter. Right? And, and you’ll know and it’ll tell you the fork offset and fork rake and will tell you the head angle. But a lot of times it’ll also just tell you trail the say right on there. And even some will even tell you We’ll flop and and we’ll flop is measured in it’s a distance measurement. It’s how much that wheel drops when you lean it. So if you had other bikes that you like that you know how you’d like that, that handling, then you can look for that you write for that kind of trail,


Chris Case  42:14

it’s like its own language in a way you look at a geometry chart, and you can say, okay, and there’s obviously you get the frame size that you’re looking for within, and then those several key points and you think, Oh, I know how that bike is going to handle to a pretty certain degree. But it’s takes a little while to get to a point where you can read that as its own language, I think, which brings up an interesting point in my mind, which is, throughout the bicycles history, we’ve seen trends in geometry where things are steeper or shallower things are tighter or shorter, all these types of things. I’m curious, you’ve been building bikes for 37 years. Why does that happen?



A lot of times it’s driven by performance reasons. And a lot of times it’s driven by fashion. So the ones that tend to stick around are ones that are driven by performance reasons, the ones that don’t are the ones that are that are fashionable. And so one thing that I’m aware of that road bike manufacturers now that all their geometry is online, and we can look at it, the guy says, well, geez, I’m gonna write a 56 centimeter bike, but look at the wheelbase on this one is a lot shorter than the wheelbase on that one. And with the same length top tube, so I want the shorter wheelbase, they’ll believe that for whatever reason, the shorter wheelbase, it’s going to be quicker and tighter, and it’s going to turn faster and all that sort of stuff. Well, it may or may not, depending on what these other things we’ve been talking about are like the head angle the for grading, if what you do to reel it in, is to make the head angle much steeper, well, that’s gonna tend to make the bike a lot less stable or cheap twitchy. Or if you instead decided to well, the way I’m going to reel it in is to make the fork rake a lot less. Well, that’s going to have the opposite disguises, it’s gonna make it a bunch more stable, it’s going to be much harder to get into the turn, even though you got this short wheelbase and you think it’s gonna be really quick turning, it ain’t going to be quick turn. Yeah, right. So I’m not sure that fully answered the question. So that so that would be an example of something where fashion is, it’s like, everybody’s like, no happens to be on a kick at the time. I want to short wheelbase. And so you’re all looking for bikes with short wheelbase


Chris Case  44:35

trying to differentiate themselves in some way, perhaps



Yes. Or the consumer believes, you know, somehow that that’s what some famous coaches said, you know, you want a really short wheelbase. And so now everybody’s looking for that and then and then over time, that would tend to just cease to be part of the conversation because those bikes suck, then people would end up fighting you know, and relaxed toward a geometry that that worked better.


Trevor Connor  45:03

So I have a question for you, because you’ve given me a couple aha moments here, back in 2007, I was on this bike that I loved. And I just whenever I descended on it, I felt like it just snapped through the corners. I mean, I’d look at a corner, and I’d certainly be through it. The following year, I was on a bike that I didn’t love, it felt more stable, I always described it as a tank, it was great going in a straight line. But when I was descending, I had to wrestle it through the corners. And so my aha moment here is I’m guessing that 2008 bike had a really big fork trail versus the bike and 2007. So I guess my question is, what, why would you want a bike like that?



Well, one would be a time trial, flat out time trial, you want to be able to just go sleep on the bars and just pound the pedals. And especially when you’re in a aerobar position where you got all this weight on the front end, you don’t want to have a twitchy front end at all, you want to have a super, super stable bike, but it requires there is cornering and a time trial. And particularly, you know, if you think of what a lot of people’s district time trials like it’s straight out, and then it’s got a U turn at the end, and then you go back, and a tight U turn, well, you don’t want to take forever going around that U turn Well, if you have a super super stable bike, and you get to that turn and you try and do your normal turning stuff, you’re gonna have to slow really, really far down and but if you understand this countersteering we were talking about because of overcoming this natural stability a bike you can actually whip that bike around super, super fast, if you’re just really pushing forward hard with your inside arm pulling in with your outside arm, and you and you’ve obviously practice it someone gotten used to it, you can whip it around, and then you just go to sleep again on the bars and pound as hard as you want. And and if you’re not expending any effort and energy, keeping the bike going straight, then you’re going to go faster.


Trevor Connor  47:02

That’s fair. Or the third option with the cornering. I remember 2010 nationals watching Swain tuff come down this steep descent to a 90 degree turn and didn’t come up as aerobars just went into that turn went into somebody’s front yard, right through their front yard through the head just back out into the road and never came out there of ours. That’s



one way to do it. Yeah.


Chris Case  47:24

I mean, every bike is a compromise. Right? You know, it’s a balance between the maneuverability and instability or stability and instability. And so that’s what all of these things that we’re talking about ours the nuance and changing when you’re talking about head to bangles between a tarmac and an Amanda, could be a half a degree. Or, you know, we’re talking about very small differences on paper that add up to sometimes big changes in characteristics, sometimes almost indiscernible changes



in characteristics, especially if you if you then add in something about the wheel and tire because you also have probably had the if you’re a cyclocross rider, for instance. So cyclocross riders tend to mess around with tire pressure a lot, but they don’t mess around with tire diameter at all, because 33 millimeters is what allowed it’s 700 by 33. Seat tires, what’s allowed with


Chris Case  48:20

you said diameter, width,



right? Well, both are still using 700 c wheel Yeah, the same diameter, and the same tire width. So it ends up being the same wheel and tire is the same height, same diameter, and nobody’s going to go to a skinnier tire, it just isn’t happened, right? People use 700 by 33, c four. But there are some courses where it’s a huge advantage to have really, really low tire pressure, right. For instance, if it’s really muddy, you might want to be at as low as 14 psi or something. Well, if you then are riding that bike, you’re used to your road bike riding a certain way, and you’re on pavement and you do a sharp turn. It’s really like turning a truck because because you have you’re now trying to counteract all this dry friction of the of this big contact patch on the road where you’re used to a certain much smaller content patch and the bike rails through the turn. And now it’s like, what the heck you know. So there is like if you were comparing, like you said an ammonia on a tarmac or whatever, but if you were if you were nowadays we have all these gravel disc road bikes and gravel disk road bike, you generally have a lot of ability to change the diameter of the tire with the tire and, and it does change the diameter of the wheel. So then you’ve you’ve now by having a bigger wheel diameter, you’ve increased the fork trail, you’ve made the bike more stable, just putting a taller, taller tire and wheel in there. But then you’ve also increase the stability by running a bunch softer pressure because you’re going to ride it on gravel but then when you get on pavement Like, it’s not going to handle like the tarmac and it’s because of choices you made, but it very well might. If you put, you know, 23 millimeter tire, pump it up hard, put it in there, you might discover, hey, whoa, this does handle as quick as my tarmac.


Chris Case  50:15

Mm hmm. So you’ve talked about your senior project at Colorado College in the trying to build the unraidable bike. What else has informed you over the years about how to build excellent bikes? Well, there



was a eureka moment for me in 1981, Memorial Day weekend 1981. Back in the 70s and early 80s, one of the one of the certainly one of the biggest single day road races in the country was Durango Iron Horse. It was it’s a, it’s a race that you raise from Durango to Silverton over two big passes, about 12,000 foot passes, and you you race the narrow gauge train. That’s how it started, because there were two brothers. One who right was bike rider one was a conductor on the train on the narrow gauge train, and they had a bet over who would get to Silverton faster. And so and for a while, that was always the consistent started in the same place, and it ended in the same place. So there’s actually a time that was associated with it. So there was a record time. And in 1975, George mount who was very famous American cyclists set, set the record two hours, 15 minutes, 55 seconds, and oh my god, nobody’s ever gonna beat George. Now,


Chris Case  51:30

I like that you remember that number? Yeah.



And then, and then in 1980, I won that race. And I did to 1048 by more than fourth by more than five minutes, ebike and, and I and now, now it’s it’s slightly different course length, and whatever, but people go much faster. But in any case, I you know, I grew up as an alpine ski racer, and was and started racing bikes, because I was on the alpine ski team in college, and I had all these knee injuries and the way I dealt with the knee injuries was and to avoid surgery was riding a bike. And so I tended to go downhill very fast. And that’s how I dropped my one breakaway companion was, I dropped him on both of the sense and let him catch up after the first one. But then I didn’t have the second one. And I had a bike at the time, it was mozzie, made in California by Mario content, de who was one of the original protegees of folio mozzie. And he came over to us and he was given the rights to use that name. And it was just a fantastic bike. And I could go really fast on it. But I’m a tall guy, six and a half feet tall. And then after that season, I got put on national cycling team, I now had sponsors and got sponsored bikes. And next time 1981 comes around, and I’m now the defending champion doing this race and get over the top of the first climb with the group start going down and my bike just starts shaking uncontrollably as I got up to high speed, and that was I had no idea what was happening. And the only thing that I knew that I could do was put the brakes on let everybody go and go slowly down the sand and then it happened even worse on the descent into Silverton,


Chris Case  53:14

you’re not going to tell us what brand This is or you know, okay.



So, it was another Italian bike Made in Italy though. But I, at that moment, I was weeks away from finishing my, my degree in physics, and I’d already done this, my senior seminar on stability of bicycle, I was like, this is ridiculous, I could do better than this myself. I’m gonna, that was the moment where I said, I’m going to build these damn things myself. And it turns out that that’s a totally different issue than what we’ve been talking about this high speed shimmy of a bike and and I asked what is that? Yeah, I thought I could solve it with the same things that we’re talking about making the bike more stable. Well, that’s not it, it has to do with


Chris Case  53:59




Yeah, frequencies. But specifically, it’s called a Hopf bifurcation is we won’t go into the details of that. But one way to kind of clear now Thank


Trevor Connor  54:09




One way to think about this is a is a is a resonant frequency of something where you know, you if you put in the input, the frequency input, at the resonant frequency, then the free the oscillation will build and build and build, the amplitude will grow. If you apply a different frequency, it’s not going to excite this this resonant frequency. And that it just so happened that, you know, the taller the bikes, the further the tubes get apart, and at the time, all the bikes were lugged so that tube diameters were always the same, those were fixed and pretty much the angles were pretty much always the same on all bikes too, because those were also is fixed by the by the lugs. And so when you get a really tall bike with the same skinny tubes, as you know, somebody riding a 52 centimeter bike, there’s going to be a lot more back and forth twist to that thing. So so that the amount of time that it takes the bike to go back and forth through one complete, twisting back and forth oscillation is much greater than on a much tighter. So you’re saying like the front end


Chris Case  55:10

and the back end of the bike are oscillating back and



forth Exactly. And so and this resonant frequency of oscillation is now so much slower than it tends to be, it can easily be set up by the kind of frequencies that you encounter on the road, the bumps on the road, the wind, things like that, because because often people will find they have a bike that they never knew shimmied on them, and then they come down a big hill in a winds, you know, high wind, and then all of a sudden, it’s shimmy like crazy. Well, that’s just the extra little, little bit of frequency added that was required to get it into that resonance zone. So that took me a lot of time to figure that out, and how to make a bike stiffer. And also also the heavier the rider the longer that bike takes to go back and forth through that. So you can have a bike that for me at 175 pounds would be great. I’m like this bikes got this handle, I can ride at 50 miles an hour downhill, no hands, well, 350 pound guy, somebody double my weight. Now that resonant frequency has dropped a bunch and now that same bike will shimmy like mad on him. So. So those were the things that took me a lot while to figure out that are completely different. There’s they’re related to these things we’ve talked about. But it has much more to do with the torsional


Trevor Connor  56:28

stiffness of the bike. So what our bike manufacturers doing now to prevent that shimmy?



Well, one thing they do is they don’t make bikes for really tall people. That’s why I have that’s why I have this niche. That’s why you still I have a business because I don’t try and go up against Trek and specialize in everybody. And and yes, it is the case that carbon bikes, the investment in the molds are so high that, that you have to amortize those over a lot of units in order to make it worthwhile. And if you look at the bell curve of people sizes, and you go, well, geez, there’s nobody living out there. And that little low part of the bell curve, we’re not going to sell enough bikes to make this worth it. And so, you know, they’ll stop at 60 or 62 centimeter or something, and then the guy that drives the 70 centimeter bike, you know, he has to come to somebody like me. And fortunately, I have this business, because if a lot of times people would go to a Short Frame builder, he made him a 70 centimeter bike, and it would cheer me because he didn’t understand the problem. So but in general, one of the benefits of carbon fiber design is that is that each bike size can actually have its unique shape. So instead of the old days where the tube diameters were fixed, and the angles are fixed, now you could you can make the tube sizes grow and make the whole area around the head to get much bigger on the bigger bike than on the smaller bike. And


Chris Case  57:56

I guess that explains going back to why there might be distinct



types of geometry for different arrows. Some of that was constrained by manufacturing and the availability of certain things. Yeah, a lugged bike from the 70s is pretty set in its ways. Now we’ve got a lot more options because it’s easier to do what you just explained and give people more choices based on the manufacturing abilities. And this could very well have to do with why mountain bikes didn’t exist before they did. Because Joe breeze and Tom Ritchie Joe breeze built the first five breezers or 410 razor whatever it was, that was sort of the first purpose built mountain bike and and if you looked at it had these direct lateral tubes that went all the way from the rear drop out all the way to the head to like a tandem. Well on a tandem those guys. Tom Ritchie and Joe Brees both did build some tandems and tandems require clearly much bigger tubes and these longer lengths and the angles are different and you got these lateral tubes going the whole length to stiffen it up. Well, in order to do that you’re going to have to come up with a different method of putting together than lugs and so that’s when they came up with is Philip braising and then they could then they were no longer constrained by the size of the tube, the shape of the tube or the angle. And so that allowed them to make these bikes in the first Ritchie’s I mean now you know mountain bikes hardtail mountain bike has a lot closer geometry to a road bike now than those those Cheryl’s had really SAP shallow seat angles, really solid shallow head angles and, and part of it was because they were, they were sort of following the designs of these old clunker bikes that they were riding on town which had that that kind of geometry and so there were bikes that they liked among those they tended to kind of mimic to mimic mimic it but they never would have been able to come up with that. They’ve been stayed constrained with lugs, the fact that they, that they got away from that. And then of course, TIG welding was a cheaper version, cheaper, lighter version of Philip braising allows you to do any angle any, any tube shape.


Chris Case  1:00:13

One of the other questions I had for you is, you know, I love to talk to people that have been riding bikes for a really long time. And they always have like the man that they rose from 1973 that I wrote, oh, my God, I’ve never written something so nice in my life. You know, I want to know what it sounds like you had one that masih that you bombed those two cents at Iron Horse. I know you probably haven’t written many other people’s bikes besides your own over the last 37 years, because you’ve had the ability to make whatever you wanted. But I’m I just for a little color. I’m curious if there are any bikes where you just were in love with how they handled in what made them handle so well, in your mind? Maybe it was one a bike that you’ve made, and



oh, yeah, I mean, definitely it was bikes I made, but that put that mozzie. I mean, in terms of when I was buying bikes that I wasn’t making, there was nothing that wrote like that, like that. And what


Chris Case  1:01:14

made it so special? Do you know that the specifics of that,






At the time, the bike manufacturers, when they made a really tall bike, they made it the same, it had the same fork, just a longer steering to bottom at the same fork as all the rest of the size run. And they just reeled in the wheelbase by making the head angle much steeper. So like the one that shimmied on me so badly, going down to Durango that one had a 76 and a half degree heading, which, you know, anybody that knows much about that stuff is like, what that’s steep. Yeah, especially if it has exactly the same fork rake as all the rest of the bikes in the line, which are running more like, you know, 73 right. 74 head angles, but this content they mozzie that I had, you know, it had a much more reasonable heading on a 74 degree head angle. And it also had decreased the fork rake a little bit from from what you know, the rest of this size run. And it was just a really sweet feeling bike and, and and it had heavier gauge tubing, so it didn’t shimmy also because it it it had Reynolds 531 tubing, which you never find on Italian brand bike with Reynolds doing rails 531 that was slightly thicker than the Columbus SL of the bike the following year that shook so badly.


Chris Case  1:02:42

This might be getting into the weeds, but bikes have been around for hundreds of years. How did they arrive at some of these places? Just through trial and error? experimenting with head angles and and the other elements and figuring out what made it ride? Is that or Yes, yeah, exactly. Right.



I mean, and when you think about Penny farthings all the original bikes, there was no fork offset, and there was no, the head angles were 90 degrees, right? You don’t have to be a rocket scientist nowadays to realize that would have been a harsh riding bike. And then also Penny fires. Yeah, this other problem was if if you hit something that stopped the front wheels, you were just going to go launch launch straight from a very high height, you know, right on your head with no helmet on. And so certainly lost some riders and in the process figured out more you know, and the first the first improvement was the, quote, safety by cigarette, which was meant to prevent people from falling on their head from really high height. And then once that change had been made, where you where you disconnected the pedaling from the front wheel, then you could now now it gave you the flexibility to start changing these geometry items that we’ve been discussing. And then then yeah, then it was hundreds of years or 100 years of trial and error that that ended up sorting it out. But certainly the early bikes, people had no idea and they just try something, throw it against the wall and


Chris Case  1:04:12

see what stock is there anywhere to go from here. Will we continue to tweak with geometry? Or is there we’re pretty constrained within the what makes a good riding bike at this point?



Well, it’s very hard to see the future and to know what’s going to be happening and tire size and tire performance that will always affect geometry. And also, for instance, as we get into ebikes and bikes get heavier and they get faster and that will also inform geometry. I don’t see if things were to stay the same tires are similar to what they are now riders are going similar speeds and they’re way similar amounts and I think we’ve dialed it in pretty well for really nice handling and That’ll it’ll take other things changing before those, those parameters are gonna change, I think.


Chris Case  1:05:06

Here’s one last question, I guess from from a, from a, from your point of view, specifically, as a owner of a bike company. How do you make all the decisions? How do you go through the decision making process when it comes to choosing the right angles and things like that?



Well, I, first of all, take the measurements of the rider Mm hmm. And I also talk with them about what they’re going to use it for. And if I have really my druthers, I would actually send them out on if if they happen to be close to my size. For instance, like recently, last few weeks, I sent out a rider who bought buying a bike for me on one of my bikes, and I put a different stamp on there, move the seat position around, so that he was going to be set up like he would be on the new bike, and then let him ride it for a couple of weeks and got his feedback on what he liked about it and what he didn’t. And then I can make a really informed decision. And also, if somebody has specific, specific particular medical issues, but you know, pain here and there and whatever, then we have this cooperator, Lane’s arrangement with university Colorado sports medicine Performance Center, where it grew out of the work we used to do for years with Andy Pruitt at the boulder center for sports medicine, where, where the writer goes in, and I go in with them, and I already have a design that I’ve sent to them and they set up over at cus MPC, they set up the fit bike with that geometry, and then the guy can come in and you can ride it and and we can make changes while or even pedaling, we can raise the seat, push forward, back, raise the bar, push it forward back, all while without even getting off or why don’t even stopping pedaling. And look at saddle pressure distribution on the saddle, we can look at the actual movement of their joints, but with optical capture of the of their the tracings of the what their how their joints are moving in space. And that’s kind of the gold standard, we actually call it our gold metal fit is where more information I have the the better job I can do in in building a bike for the guy but but it also really helps for him to tell me or the woman what they like and don’t like about their current bike or their bikes they’ve had recently and and then from that I learn a lot too I can, okay, if they didn’t like that, then I know, make this change.


Chris Case  1:07:43

I want to talk about the process somebody should go through as a consumer to understand what they might look for sort of guidelines to find the bike that’s right for the application they want to ride. Are there any guidelines that you give to people about look for a head angle that’s between this and this? And it? I’m sure it also gets complex because of all the interplay between these things. But what are your guidelines for that process?



Well, first of all, it’s going to completely depend on the application. For instance, somebody is going to be doing gravity assisted mountain biking, you know, sharing their bike up on the chairlift and ripping down mountain bike trails is completely different geometry from regular road riding, which is also subtly more suddenly different. But importantly, different from if they’re riding criteriums. Or if they’re riding a track bike, and on a track a bank track. And I also would say that, you know, assuming somebody’s buying a stock bike, big brands, they make great handling bikes for the application. So it’s important to understand the application. So it doesn’t make sense if you’re an 85 year old guy pedaling at 12 miles an hour to buy the bike that Peter Sagan get right, you’re looking for different performance characteristics. And well, that’s


Chris Case  1:09:11

making a big assumption. I mean, that guy might be pretty strong.



Yeah. It could be. Could be so. So what I would say first of all, is if you’re an experienced rider, and you know exactly what you’re what you’re going to be using the bike for, and you have existing bikes that you’ve tried in that application, and there are some that you like and some that you don’t then you particularly look at, mainly for trail but also the head angle fork rake how they got to that fork trail with given wheel size and and you mimic that and then in the new bike you’re going to get just because a bike works great for somebody who rides it completely differently from you doesn’t mean it’s gonna work for you. And if you’re not an experienced rider, then you then you go with somebody you Trust, who ride similarly to what you ride or what you’re planning on riding. So, you know, if it’s your first time that you’re going to be riding a, you know, say a downhill bike, you want to get a downhill bike for taken to Whistler or something and you don’t know you’ve never written down and you don’t know anything about it. Well, you don’t necessarily want to then see what greatest downhillers are looking at. But you’d want to find somebody who’s got some experience at it, but maybe isn’t that good at it. And, and has bikes that they that they like, and they’re going to be, but they’re going to be tend to be more riding the speed that you’re going to be riding rather than the speed that Greg minnaar rides or something. So if you don’t have the personal experience of what you’re looking for, then you seek out somebody who, who, who does. And is is riding in a similar way to what you’re gonna write


Chris Case  1:10:55

  1. Unfortunately, it’s not formulaic, you can’t say, You’re this type of rider, you want a bike that has 73.5 degree head to bangle break of this, you have to do some homework to understand what you need, given the application, given the skill level you have, and



also given your size, right? That it’s not going to be the same recommendation, or the same people writing the same sort of circumstances, or one of them’s five foot two and one of them six foot two.


Trevor Connor  1:11:25

Has there been any bike manufacturers realizing these particular geometries people seem to like more, and these tend to sell better? Do they have any sort of awareness of that? And oh, yeah. Oh, yeah.



They definitely are getting feedback from the field and, and attempts to hone their designs into be good work for work for most people who are want that application that, you know, we talked about? tarmac, you know, I don’t think you’ll find too many people who raise bikes and they buy a tarmac to think, Oh, this thing I don’t like the handling of this, you know, they’ve got that pretty well dialed in, you know, they’ve been, they’ve been working with a lot of racing teams and a lot of individual riders, and they take the feedback. And for that application, if you’re going to be going fast on that bike on the road, it’s probably gonna work pretty well. Mm hmm.


Trevor Connor  1:12:15

So it’s a good old bell shaped curve, that it’s there come up with the geometries and wear for the majority of people. And for those people on the size of the bell shaped curve. That’s what your business does? Well, yeah, that makes sense.


Chris Case  1:12:26

Well, we started this conversation, and Trevor said, you know, I’m a retro grouch. Basically, what he was implying is that, it doesn’t matter what bike you buy, it has two wheels, put some pedals on it, you can do whatever you want with it, which is, you know, that’s true, basically. But a lot of these things make a big difference. Trevor, are you convinced that these things make a big difference?


Trevor Connor  1:12:51

I’m gonna upgrade my response. How about that? Okay, sure. So very quick background, when I was living in Ithaca, New York, they did an experiment where they took frames of different materials, and painted them in a way that you couldn’t tell which is which. And then I had a whole bunch of experienced cyclists ride them and tried to get them to say, you know, which bike is which bike, only one of the some hundred people in this experiment actually got all three bikes, right. And I know him, I asked him about, he’s like, I was guessing. That’s true. And what they got out of that experiment was the thing that people notice was the fork in the wheels. So that’s always been my, my basis. But yeah, I’m gonna upgrade it to this, as I was telling you that 2007 2008 experience I had you bikes felt different. It wasn’t the frame material, they were the same material. It was the geometry. And it does, you know, I didn’t know half of these terms. I’ll admit that fully coming into here. This all makes a lot of sense. And it really the, the geometry of the frame seems to have will have a huge experience effect on your experience with the bike.


Chris Case  1:14:00

And it could be that the bike in 2007 was great. You felt it when it was at its greatest on the sense that it doesn’t make the 2008 bike necessarily bad. But maybe it was the application again, on the sense it wasn’t so maybe it was it would be better for something else.


Trevor Connor  1:14:18

So I was asking I’m my guess was I would just be me and being an idiot and getting a bike without knowing what I should have known and bought the wrong bike for what I was trying to use it for. And I’m sure that bike had great applications in other places. That’s why I was asking the question, Where would you use that bike? Obviously, it was not the bike for what it was. So no, I yeah, to answer your question, Chris. I am a retro grouch mostly out of ignorance and stubbornness, because I am in any way right?


Chris Case  1:14:50

Okay. Very good.


Trevor Connor  1:14:54

So the one serious side of my retro grouchiness is What I don’t like is when people read something about oh, this bikes got a tighter wheelbase or steeper heading on the go, that sounds cool. So I need to get that like, I don’t think that’s the the way to make purchases. And there was a lot of really good information shared here. And I think when you take the sort of knowledge that Leonard shared and start asking the questions, do I want a steeper head angle? Do I want more or less fork trail and then make your decisions based off of what do I want? What do I need? What sort of application my using it for then I think you’re making great choices and all this stuff does matter.


Chris Case  1:15:32

It comes back to science, Trevor, it’s all about science. Science wins.



Yay, science.


Chris Case  1:15:42

Great. That was another episode of Fast Talk. As always, we love your feedback. Email us at Fast Subscribe to Fast Talk on iTunes, Stitcher, SoundCloud and Google Play. Be sure to leave us a rating and a comment. I can’t stress it enough. rating us positively and commenting on us positively on iTunes helps other people find Fast Talk just the way the search functionality works on that site. So if you like fast doc and you think others will benefit from it. Take a moment to go on there and give us some positive feedback. Become a fan of Fast Talk on slash Belen news and on slash velonews. Fast talk is a joint production between velonews and Connor coaching. The thoughts and opinions expressed on fast dock are those of the individual for Leonard’s in Trevor Connor. I’m Chris case. Thanks for listening.