Tom Butler: 0:04

This is the Cycling Over 60 Podcast, season 3, episode 16,. What About Oval? And I'm your host, tom Butler? I ended up doing an experiment that I didn't really mean to do. When I got my indoor trainer in November, I spent a lot of time trying to figure out how to use Zwift. For a couple of weeks, I did nothing but virtual rides. Then we ended up having a real disruption during the holidays and I spent a couple more weeks riding Zwift. That continued on for enough time that I decided that I would only do indoor riding for two months.

Tom Butler: 0:47

I thought it'd be interesting to see how well virtual riding did in keeping up my fitness level. One of the last outdoor rides I did was a 37 mile ride on a pretty flat route, so I decided to repeat that route and see if I could match my performance after the two months of virtual riding. During the two months, I logged about 41 hours, 447 miles and 18,000 feet of climbing. Over the two months I continued to set personal bests for power output, so my question was could that be enough to keep me in shape for the road? When I did the 37-mile ride in November, I set a personal best for 50k, so it was a solid effort. I averaged 14.7 miles per hour with a heart rate average of 145 beats per minute. I did the ride again on January 25th. My average speed then was 14.2 miles per hour and my average heart rate was 150 beats per minute. I see that as a significant difference, and I have no doubt that I wasn't able to keep up my fitness level with the virtual riding. The difference between 14.7 and 14.2 could be attributed to just a difference of how I would be feeling on a good day versus a bad day. However, it wasn't just the slower time. My legs were in significantly worse shape after the January ride in comparison to what I did in November. I could feel them consistently cramping up for the last 10 miles. In addition, the next night I had some of the worst cramping I have ever had, and there was a section of my quad muscles that were very sore, like I hadn't been exercising them at all.

Tom Butler: 2:12

One potential explanation for this is that I just don't ride long virtual rides. I find riding by myself on the trainer to be hard to maintain for more than a half an hour. I only had a few rides over the two months that were longer than an hour. I have no doubt that that left me unprepared for the 37 miles that took two and a half hours to ride. But I also think that part of it might have been that I just don't climb the same way in the virtual world as I do in real life. I do think that virtual riding for two months did help me keep my cardio capacity from getting destroyed. I actually felt great from that perspective on the ride in January. Even though my average heart rate was higher, I still felt like I had plenty of gas left at the end of the ride. It's just that my legs are so trashed. Here's my final conclusion I simply have to keep doing longer rides on the road to keep up my leg strength and stamina. The trainer isn't going to maintain my leg strength, but I think if I do high intensity interval training in Zwift and keep working to increase my FTP, the virtual training will play a role in building my cardio capacity for the road. Also, I need to experiment with ways to make longer virtual rides more appealing to me when I can't make it outside.

Tom Butler: 3:23

I have been thinking a lot about having a weekly virtual group ride. Here is what I have come up with. It's helpful for me to ride in the afternoon. So I'm going to do a weekly group ride at 3 pm pacific time on Thursday, and I'm starting it on February 6th. I would do the ride without rubber banding so that people who want to ride fast can do so. However, I'll personally maintain a one watt per kilogram pace for the ride so that those who want an easier pace can have that as well. I would love it if someone would lead out with the higher intensity group. Let me know if you're interested in that. By not rubber banding the group, it means that people can go for sprints and climbs and also race for the finish and yet still have an easy going ride for those who want that, and I also open up a Zoom call during the ride so that we can have some interaction. I've set the event to Cycling Over 60 Zwift Club members. Only that way we can keep the atmosphere positive. I still have a lot to learn about running group events, so expect some bumps along the way. If you're on Zwift, please consider finding the Cycling Over 60 Club and joining our ride.

Tom Butler: 4:26

Final note for this week after using Stello continuous glucose monitoring for a few months, I'm going back to Freestyle Libra. I'm just really unimpressed by the function of Stello. Getting the Freestyle Libra means that I'll about double the price that I pay for CGMs, but for me I think it's worth it, and I'm going to be making some changes and I want a CGM that is reliable. I still would like to try Lingo, but they don't have an Android app, so for now it only works on iPhones. Continuous glucose monitoring is something that I see as valuable, and I will continue to give updates on how that goes for me.

Tom Butler: 5:12

Ever since I got back on the bike a couple of years ago, there's been something that I've wanted to investigate. 30 years ago, when I was riding a lot, my bikes were fitted with Shimano Biopace chainrings. I didn't really think about it much at the time. It was just what the bikes came with. When I purchasedopace chainrings, I didn't really think about it much at the time. It was just what the bikes came with when I purchased them new. The bikes I have purchased in the last couple of years didn't come with Biopace and it was never presented as an option, but I have been curious about what happened to non-circular chainrings. I decided to get Garen Myler to join me and take a look at what is happening in the realm of oval chain rings like BioPace. Here's what we discovered. I'm joined today by Garen Myler, the official mechanical engineer of Cycling Over 60, and, as many of you know, my son-in-law. Thanks for joining me again, garen.

Garren Miler: 5:56

Yeah thanks for having me on.

Tom Butler: 5:58

You probably have set the record. I mean, I don't think it's probably close, but you've probably set the record for the most time anybody has been on the podcast. So that's how valuable you are.

Garren Miler: 6:09

I'm glad to hear it. Yeah, I love talking to you and I love the conversations we have because I think there's a lot of really nitty gritty interesting things to talk about, especially from the perspective of my field of engineering. So I'm excited to talk to you today.

Tom Butler: 6:21

Here's what's going on that I want to talk to you about. Somewhere around 1989, I should probably know exactly when that was but I purchased a Trek 1500. That bike still hangs in my garage and you're familiar with that bike, I know Absolutely. You used it for some time to ride to work.

Garren Miler: 6:41

It was actually the bike that got me into cycling. Now, uh, it was the first bike that you loaned me to to actually get me pedaling and, uh, and that was what inspired me to, you know, get my own bike, uh, you know, more modern bike. And it wasn't just that that bike wasn't good enough, though, I did get run over by an suv on it, um, but definitely we've been able to restore it back to its former glory since then we did have to do a little work on it.

Tom Butler: 7:03

So one of the big features of that when I bought it was BioPace Shimano BioPace and you know they were excited about it at that time and selling me on the technology, and the truth is I really liked it and so you know, when we restored it it got restored with BioPace on it, which I'm happy about. I don't know if you feel like you rode it enough to have some opinion about it.

Garren Miler: 7:32

Absolutely. From the moment I saw the bike with Biopace and I learned what Biopace was and the oval chainring, I was like why don't all bikes have this? This seems like such an awesome idea to me and conceptually I love it. I will say when I rode that bike and I haven't really ridden it recently I certainly wasn't an experienced enough cyclist to really know the difference. You know, all I was doing was spinning the pedals and, like you said, getting to work most of the time. So for me I didn't really notice the difference physically.

Garren Miler: 8:02

But I'm also, you know, I'm not racing the Tour de France, I'm not splitting seconds and grams and you know, and calories, I'm just. I was just cruising around town. So I really would love to, uh, to see if I could tell a difference today on it. But of course, that bike is so radically different from from a modern bike at this point that I probably wouldn't know what was due to the oval chain ring and what was due to the you know, wildly different geometry than I'm used to yeah, that's a really good point.

Tom Butler: 8:26

When I got back into cycling a couple years ago, I didn't see bio pace anywhere and I wondered whatever happened to that. Those oval chain rings and what are those things about when you talk about, like, modern bikes are very different. And I thought, well, maybe one thing is that you know, with all the changes, that you know something like BioBase is not warranted anymore. But I've been curious about it, you know, and I'm still curious. So I thought it'd be fun to do an episode around the topic of oval chainrings and have you join me, because I know that you have some perspective on why the oval chain ring would be interesting for people to think about or to use. So here's the main question Do we no longer see oval chain rings because they're a bad idea, or is there maybe another reason?

Garren Miler: 9:20

I think you see it in cycling a lot. You see it in many sports. You see it with cars as well, where the upper echelons of the sport are really what shape the trends that trickle downwards into the amateurs and the non-professional enthusiasts. And I think that the chain ring is an awesome idea. That probably didn't help people on the Tour de France as much as they hoped it would, and now the average Joe doesn't get it anymore. But I really do think that there's some merits to this and I'd love to talk about how I think that an oval chainring can be a huge advantage for a regular guy.

Tom Butler: 9:53

No, I think it's a really good comment. I think that there's a lot of things that you would see that professionals are using that. Someone like me. It's just not. I'm just not riding the same kind of bike or doing the same kind of things that they're doing. So to me there's an interesting aspect of this, and that's that if you look back, you can find an image of a bike with an oval chain ring, and that bike came to market in 1893. In 1893. I find that interesting because the safety bicycle, you know, which is what we think of as the beginning of the standard bike design that we see today it wasn't introduced until 1885. So it seems like almost immediately, people started thinking about oval chain rings. My question is you know, even back then, as people just start riding the safety bicycle, what do you think people might have been experiencing? The pedal stroke that would have been noticed in early chain drive bikes, and you know why they might be thinking that an oval chainring would be good.

Garren Miler: 11:01

Well, I think to answer that question you don't have to look any farther than the name that Shimano chose to give their oval chain ring BioPace. Bio, meaning it's about the mechanics of your body. The human body, obviously, is made for walking and running and that's what your legs are meant to do. And pedaling isn't exactly that, but it's close and it's something that your legs are pretty good at, but it's not technically a natural motion. And it's something that your legs are pretty good at, but it's not technically a natural motion, it's an adaptive thing, and so an oval chain ring is a way for you to help better utilize the mechanics of your legs to do something they're not quite meant to do. And I think that's probably the thinking that would have led people so early on to trying to adopt an oval chain ring on even the earliest bikes.

Tom Butler: 11:42

So it was noticed early on in then 80s. So quite a bit down the road, shimano did introduce bile pace. I want to acknowledge that some excellent information on the topic of non-round chain rings come from writing done by Sheldon Brown. If you don't know who Sheldon Brown is, take a few minutes to pull up his Wikipedia page. He provided a ton of really good information on bicycle technology until his death in 2008. You can still find that information on his webpage, sheldonbrowncom. I'm really happy to have discovered who he was and the information that he left behind. I look forward to going through it more.

Tom Butler: 12:25

Biopace is different from classic elliptical design. Now I'm quoting Brown here. Quote BioPace design is based on a dynamic analysis of the motion and momentum of moving cranks and legs, unlike the static geometric analysis that produce classic ellipticals, and you can find that on sheldonbrowncom. Forward slash biopacehtml and I'll put that link in the show notes. I think it's interesting what he says here, and maybe Garen, if you could just break this down a little bit. So biopace is designed on a dynamic analysis of motion and momentum of moving cranks and legs and he contrasts that with static geometric analysis that produced classical ellipticals. So what's the difference between dynamic analysis and static geometric analysis.

Garren Miler: 13:30

So a static analysis is going to be looking at the leverage that your foot is going to have versus the pedal at any given point on the pedal stroke, but it's not going to take into consideration factors like torque or the speed of your pedal or the momentum that you're carrying through the mass of your foot and the pedal system as you go around the stroke. All it's going to look at is essentially how much force can you exert, given the geometry of your leg and the geometry of your bike, for a given location in the pedal stroke, and that's a great first pass and that's going to get you a pretty decent outcome. But a dynamic analysis is going to go much deeper into actually what it's going to feel like to ride that bike and I'd love to talk a little more about kind of what sort of linkages form when you step onto a bike and how that's going to affect your riding.

Tom Butler: 14:22

Well, let's get into that. Ped know, pedaling a bicycle is a complex process and it involves a combination of physics principles, including torque, leverage, rotation, motion, rotational motion, friction, the laws of motion. So it's you think about riding a bike and you learn to ride a bike, or I learned to ride a bike I think almost everybody learned to ride a bike really in the absence of thinking about a combination of physics principles. But if you step back and look at it, there's a lot going on. So talk about the mechanics and the forces exerted.

Garren Miler: 15:00

I think bicycles, just to start, are something that we really take for granted because they're such marvels of physics. When you actually step back and look at the fact that you're flying down the road on two wheels, balanced upright, it's pretty amazing. But in particular, pedaling consists of what we in engineering call linkages. In engineering school, you'll have an entire class where you talk about the dynamics of linkages, and when you step onto a bike, what you're doing is you're forming a linkage that includes both yourself your legs in particular and the bike, and you're creating a system that's going to allow you to transfer power to the wheels. So when you pedal a bike, really there's two linkages that are occurring. There's the linkage between you and the bike via the bottom bracket, and then there's the linkage between the bottom bracket and the rear wheel. That's via the chain ring, and you have to think of those as separate systems. You're producing an input into the bottom bracket by spinning it, and then the bottom bracket is attached to the chain ring and that's producing an output at the rear wheel via a certain gear ratio, wheel via a certain gear ratio. So the the linkage that exists between the chain ring and the rear wheel is very simple. It's obviously, it's just two gears and when you, you know, you shift to different gears, it's still just two gears, but of a different size. Now, and that transfer is the easy part to understand. I think we can all understand the ideas of gear ratios and how the larger ring on the front, smaller ring on the back is going to make you go faster, et cetera. Right, the more complicated linkage exists between you and the bike itself, and that linkage is a question of biology as much as it is about physics.

Garren Miler: 16:40

When you sit down on the seat of your bike, you're creating essentially to simplify greatly a five-bar linkage. The bars of that linkage are firstly your thigh, which stretches from the seat to your knee, and if you're sitting on the seat, you can kind of assume that you're fixed to the seat right Because gravity is pushing you into it. So you have your hips are a joint and your knees are a joint and they're connected by your thigh. Next, you have your knee, connected by your lower leg to your ankle. Your ankle is the next joint in the linkage. Then you have your ankle to the attachment point on your pedal, and the pedal itself is a joint which rotates freely on the crank arm and then the crank arm to the bottom bracket creates the next link. And the final link is actually via the seat post of your bike, connecting the crank arm back to your butt on the seat. That's the five bar linkage that you create when you step onto a bike.

Garren Miler: 17:30

Now, when you create a linkage, a lot of dynamics are at play and in particular, you're going to end up with what they call dead zones. These are spots of what we call zero mechanical advantage. You can think of it like if you were to step onto your pedal and your pedal was facing straight upwards and you pushed down with your foot, you wouldn't rotate the pedal ring right. You have no advantage that are rotated. If all you could do with your foot is move it up and down, then at the very top of the stroke you'd have no mechanical advantage. You couldn't push down on pedal as much as you pushed on it. You would not rotate it because you're at the top of the circle right.

Garren Miler: 18:06

But if you've got some momentum into that chain ring and this is actually if you look at how train wheels on like old steam trains worked and they had those bars between the wheels it's the same kind of principle. But if you get a lot of momentum in that, what you'll do is, when you get to that dead zone, you already have a baseline velocity. So to that dead zone you already have a baseline velocity. So even if you're just pushing down, you're still going to just scooch past that dead zone and all you have to do is scooch a little bit past it and then you can push down and you're in the front side of your chain ring and you'll get some power through it right. So it's that momentum that gets you past that hump of the dead zone, right, and that's something that you need to overcome if you want to be able to move a linkage, and that's something that you need to overcome if you want to be able to move a linkage.

Tom Butler: 18:45

I want to stop you there for a second, and you know because, like you're visualizing this, I think, in an excellent way and doing a good job of talking about it, but I just want to illustrate that by something that I think everybody is aware of. Yeah, when you stop at a crosswalk or something and you are waiting for the crosswalk signal to change or the stoplight to change or whatever, now I always put my pedal position where I can get a lot of leverage on it to take off. You know, if you, if you stop that pedal position with the, with the pedal all the way down to the bottom of the stroke, then you have nothing to help you get started, especially if you're not clipped in. If you're not clipped in and your pedal is at the bottom of the pedal stroke, then there's no leverage that you have to create motion, absolutely. I think that's exactly what you're talking about, right.

Garren Miler: 19:44

That's a great example of how you experience a dead zone in everyday riding. Now, when I talked about when I illustrated the idea of zero mechanical advantage, I said you have to assume that your foot can only move up and down and that's what creates those dead zones. But in reality, obviously, your foot can do a lot more than that. You can push forward at the top of your pedal stroke, you can pull up in the back if you're clipped in right, your legs can generate power in any number of directions and that's due to your biology. And so when you're looking at the idea of a chain ring and you're looking at biopace, what you're thinking about is actually the dynamics of where your foot and your leg and that whole system can create the right amount of power at the right time. And if you want to optimize that, that's the direction you're going to have to start looking is is how can my legs produce as much power as possible, given the limitations of where they can and can't get the most leverage, given their geometry on the chain ring?

Tom Butler: 20:40

When they developed Dialpace. I think this is exactly what they were thinking about, right?

Garren Miler: 20:46

Yeah, I'm sure they were.

Tom Butler: 20:47

So back in. I don't know when it started it was, you know, came out in the 80s sometime, but they probably started thinking about this the design well before it came out, I'm sure. And so you know they're. They're thinking about the physics and if you go back to this quote, they were thinking about a dynamic analysis of motion and momentum of moving cranks and legs. As you think about this, are you seeing anything from a theoretical perspective that would say what they were thinking about was wrong?

Garren Miler: 21:24

I think that they were absolutely on the right track with the biopace chainring. I think that examining the interaction between your body and the bike as a dynamic and, frankly, very complex system is going to lead you in a direction of higher efficiency.

Tom Butler: 21:41

For me. There's another element here. I don't really feel that comfortable that I am doing a great job of pedaling in a circle and hear about pedaling in a circle all the time, but, man, when I've tried it, when I've tried to climb and really focus on pedaling in a circle, I don't feel like it's really a huge advantage for me. So what are your thoughts on that?

Garren Miler: 22:09

I think there's a lot of truth to that and, of course, I'm no professional cyclist and I don't want to talk about cycling form and what is and isn't correct, because I know that there's a million different ways that people will tell you how to ride a bike when you're racing and isn't correct, because I know that there's a million different ways that people will tell you how to ride a bike when you're racing. But I do think that to purely visualize pedaling in a circle, I think is to ignore some of the anatomical limitations that your leg system has.

Tom Butler: 22:30

It's interesting that you say that, and you're not the only one. I mean, there is an article and it's posted on gearandgritcom written by Kevin Curry. It's called the Cycling Myth that Won't Die Pedaling Circles. Now that to me is a pretty catchy title. You know the Cycling Myth that Won't Die Pedaling Circles and in the post he pointed out something that I have thought about before. This is a quote from him.

Tom Butler: 22:59

Extension muscles push against gravity all the time. Flexion muscles are only used to lift up the leg. The amount of force required to lift your entire body and keep it there will always be more than the force required to lift your leg. Why, then, would you expect the flexion muscles to provide the same force on the upstroke as the extension muscles do on the downstroke? So again, what he's saying here is that when you look at like your quads that are used to provide extension, and then you compare that with the muscle groups that are flexion muscles, there's just no comparison in how they're used and how they're developed. That seems like that has to be taken into account here, but I don't hear much about that. What do you think?

Garren Miler: 23:53

I think that I couldn't have said that better myself than Kevin Currie did in that quote, because really, what this highlights to me is the difference between a professional cyclist and an amateur cyclist, and why I don't think bio pace or any of these oval chain rings really caught on at the professional level is exactly because of this concept. Right, obviously, not all of the muscles in your legs are the same size. The muscle to lift your foot is going to be a lot less than the muscles used to lift your entire body, and that makes a lot of sense. Now, if you're a professional cyclist, you know your body is moldable and you can certainly get on certain training machines or on bikes and you can pedal for six hours a day and you can train your flexion muscles to be really, really strong to the point that you are pulling up with a tremendous amount of force because you've molded your body for that purpose. Right, you've transcended that. Just, I'm just going to use my legs for walking.

Garren Miler: 24:43

And now you're saying I'm going to purpose, build my muscle set for this niche activity that we invented, that is cycling. Right, but as an amateur, that's not what I'm doing. I'm biking to work, but most of the time I'm walking, I'm jogging, I'm maybe swimming, but I'm doing other activities and I'm not necessarily going to get on a machine and focus on building those muscle groups that are naturally not as strong. So if you're a Tour de France rider, you're going to have these incredible muscles that are pulling up on your upstroke, that you've intentionally created that way. But if you're an amateur, you're not going to have that same level of bolstering on those muscles and it can't be expected for someone who's just riding a bike casually or who's racing at an amateur level. So when biopace doesn't catch on at the top, it's because, frankly, they don't need it as much, because they can compensate for that with really kind of outlandish training regimens that most people are never going to do.

Tom Butler: 25:39

I would love to see, like, some kind of investigation about this. Like, take the elite cyclists, that again you know they're training all day long, they're climbing all day long, they're focusing on their pedal stroke, like all day long as they're in training, and then you know using it as they're racing, you know using it as their racing. I would love to see, like, the difference between their ability of flexion compared to the normal person's ability of flexion and then their capacity for extension compared to the normal person's ability for extension. I think it'd be possible that you would see that. I think it'd be possible that you would see that what you're saying is that they have developed their flexion muscles in a way that most people haven't come close to, and they've also developed their extension muscles. But I just have a feeling there is a difference of their flexion muscles that even exceeds the difference of their extension muscles.

Garren Miler: 26:47

That's totally a hypothetical thing, but I think it's really possible. It certainly is hypothetical, but I think that there's a really high probability of that being the case, just given that cycling is a niche activity that you don't naturally do if you're not in that world, and so the more you do it, the more acclimated your muscles are going to become to that activity and there will be muscular differences from, let's say, someone who trained professionally as a runner right, their legs are not going to have muscle in the same areas as someone who trained professionally as a cyclist. I mean, that is, you know, just a fact.

Tom Butler: 27:16

And this kind of comes into play. You know, as I'm getting older, you know there's going to be a point. Now I think I'm still able to build muscle. You know, I'm coming about 62 years old and I think I am able to build muscle. 16 years old and preparing to be on the professional road circuit at that age and I start, you know, focused on building up muscles for a pedal stroke. You know I'm going to build the flexion muscles a lot easier that me. At my age I'm going to be able to build those flexion muscles up. So so, even if you say you know you can build those flexion muscles, I think if you're older and you haven't stuck with it, I think that it's going to be harder to you know, to make those changes.

Garren Miler: 28:19

Yeah, and I think that's exactly the time that someone should start asking the question how can we compensate for this disparity in other ways? Mechanically speaking? A noble chain ring is one way to do that.

Tom Butler: 28:30

What I find interesting, again, taking a look at this in preparation for this discussion, my interest in non-circular chain rings. It wasn't diminished at all, it was actually increased by me looking at this, and despite the failure of BioPace, there are a lot of people who swear by non-circular chain rings. So it seems like there is some benefit that people are seeing in some situations. One of the companies that seems to me that's doing more than anybody else, or as much as anybody at least, is a company called Absolute Black, and they claim to be the only scientifically proven oval chain rings on the market. So you know, this is something that's very interesting to me. I mean they are saying look, it's been scientifically proven that this is a better design for chain rings and yet you still don't see them on bikes. I know you weren't talked about. You know no one talked to you about what you might consider absolute black adding that onto this bike. You don't see Trek or Specialized, you know, coming out with their own version of absolute black or partnering with absolute black. So despite this very strong claim that they make, you know that it's scientifically proven, then it's still not making a dent, it seems like, or a very big dent in it.

Tom Butler: 30:05

I had wanted to get somebody from Absolute Black on, but they're kind of hard to get a hold of. They're European. I guess they were actually designed in England but manufactured in France. I mean manufactured in Germany. You know, there's like this real European aspect to them and I just wasn't finding somebody come on. But you went out and you took, took a look at it. So, having looked at it, what were your thoughts about what they were saying?

Garren Miler: 30:38

So the the scientific backing that they're quoting in that mantra comes from a research that was done at a university in slovakia where they measured the performance of the rider through many different metrics, and they used some pretty high-tech pedals to measure the exact power output that the rider was giving to the bike versus the power that was seen at the rear wheel right. And this is the science that they're talking about. But one thing that should be pointed out is that Absolute Black's design is very distinctly different from Biopace's design, and essentially what they did is they rotated the oval 90 degrees from where Shimano had it. So Shimano's ideology was this is a performance thing that we're putting out this biopace. This is a performance element, anyway, and obviously the 1500 that you bought back in 89 was a very high-end bike at the time, and so it had this top-of-the-line performance biopace chainring right. And so their reasoning was if you want to maximize performance, what we want to do is maximize the effectiveness of your power stroke, which, in simple terms, is just the stroke in the front end of the chain ring which corresponds to the upstroke on the other side of the bike, on your other foot, right, that's, your power stroke is when you're pushing down, so you think about standing up to climb a hill. You know, when you push down and you're standing up and you can really feel the power. That's the power stroke. And so what Shimano thought was, hey, let's increase the leverage, let's make the long part of the oval on the power stroke, and then that'll maximize performance. And so in your little stroke you don't have as much resistance, you can just kind of pedal through it and get it out of the way, et cetera.

Garren Miler: 32:13

But what they found doing that was that that was actually wrong. What that was doing is that was causing knee pain and it was causing a kind of an irregular cadence. When you think about, like I said, climbing up a hill and standing up, you have this like kind of lurching motion to your bike. As you go up the hill you're lurching a little bit at a time, and so that unevenness is going to take a momentum and also it's going to take a drain on your body because you're going to be kind of chugging through your ride. And so the Biopace ring had that limitation.

Garren Miler: 32:41

So what Absolute Black did is they rotated it the other way. They said, really what we want to do, your Power Stroke already has plenty of power. What we want to do is better utilize your dead zone. We want you to be able to pedal through that and have a little more leverage so you can push the wheel a little bit better in that part of your riding. And what they found was really interesting. It didn't necessarily produce a faster ride overall. What it did produce was less energy consumption, and that's a very simple way. They measured many parameters, but in essence, less energy consumption for the same output. And it also meant less work, work being a physics concept, but in broad terms, less work in your legs to pedal the bike for the same outcome at the rear wheel.

Garren Miler: 33:32

And this is where you have to understand what I was talking about earlier with the two different linkages on the bike. There's you interacting with the bike and then there's the bike interacting with the rear wheel. And so if you think about, like when you set cruise control in your car, your engine just spits out the same amount of power constantly. It's a constant amount of power. Your RPMs are the same and you cruise right, but on a bike that's not what's happening.

Garren Miler: 33:53

Your body is producing very different amounts of power in your power stroke, in the dead zone, all the different points in your pedal, and that that creates a non-continuous input that then needs to get rectified before it goes to the rear wheel.

Garren Miler: 34:06

So if it's just a circle on either side of that secondary linkage from the crank to the rear wheel, then the kind of irregularity of your pedal strokes that's created by your physiology is going to get transferred to your rear wheel.

Garren Miler: 34:20

But if you compensate with the oval chainring, the way that Absolute Black did, in the correct orientation, what you can do is you can take that uneven input that you're giving the bike as a human and you can sort of smooth that out into a much more constant power at the rear wheel, a constant RPM, and it'll feel a lot more like you have cruise control set on your bike as you're riding. And ideally it's not just about making more power overall, like biopace's um thoughts were. It's about better interacting with the kinetics of your own biology and creating a smoother and less painful ride for the rider, which I think is exactly what we need for someone who's not a professional, for an amateur enthusiast who just wants to ride on the weekends, and I think it's a better use of your body, it's a more efficient way to interact with your bike.

Tom Butler: 35:31

More efficient way and, it seems to me, more natural way. You know again, you're using your muscles climbing stairs. You're using your muscles doing, you know, everyday activities, lifting things up. If you use proper biomechanics to lift things, it's like having you do work on the bike more in line with how you typically work.

Garren Miler: 35:56

Right, it's more ergonomic in a sense. Almost you can think about like an ergonomically shaped keyboard that doesn't make your hands, you know, have to be so straight compared to your body. Right, and it's the same kind of concept. It's ergonomics, but for your pedal stroke.

Tom Butler: 36:11

Again, for somebody that isn't out spending, you know, eight hours a day training, you know, and training in the gym and everything, because they're a professional cyclist, right. So I do think it's very interesting, you know, if you go to the website, which is absoluteblackcc, and they have a page why Oval? And again, I'll put that link in the show notes. If you look at that, they want to make it very, very clear that they are not Shimano, you know they don't want to be associated with it. It's so interesting to me because, despite the research that Shimano would have done here, what they're saying is that they did the opposite of what you wanted to do and we have rectified that. And our research shows that when you rectify that mistake of biopace, then you do see this advantage. And again, you know, go read Y-Oval if you're interested in this stuff. And you know it might take a little time to really understand what they're saying if you're someone like me and not someone like Aaron, if you're someone like me and not someone like Garen, but you know, you kind of see what they're talking about, about the advantages that they're seeing in their research.

Tom Butler: 37:35

I want to talk about another modern player in the oval chain ring market and this is a company I think it's pronounced Ozometric. This is a company I think it's pronounced Ozometric. If you go to Ozometricde it's a German company then you can see their concept for an elliptical bicycle chainring. Ozometric is a French make of elliptical bicycle chain rings. What I find interesting is that Chris Fromm, who's a four-time Tour de France winner, excelled in a lot on the professional circuit.

Tom Butler: 38:15

We talked earlier that this might not have made sense for professional cyclists, but here you have Chris Fromm, who is who has used osometric chain rings and obviously he's choosing them. You know he's got input from team technicians and you know his own writing and, I'm sure, the testing that he did for himself, you know, and he believed in this product. And Bradley Wiggins is another successful professional cyclist that has also used Ozometric. These were designed by an engineer, jean-louis Tallow if I'm saying that right I'm sorry if I slaughtered that and he claims that this improves cycling performance. It's a non-circular shape but it's tailored very specifically. So I'm wondering if you had a chance to look at that and have some thoughts about the shape that they have locked onto here Garen.

Garren Miler: 39:30

I guess, to use an analogy, it's kind of like thinking about, like I said earlier, ergonomics. Right, if you were to grab, like, a square bar, it's not very ergonomic, it's kind of uncomfortable, it pokes into your hand, right? If you were to grab a round bar, oh, that's a little more ergonomic and it doesn't hurt your hand quite so much, right? So that's like having a circular chain ring, which is to be a little dramatic, is unnatural, right? And then you have a oval chain ring, which is generally more ergonomic. This is like taking a piece of clay and molding it straight to the palm of your hand, you know, and then when you grab it, it's exactly shaped to your hand, right?

Garren Miler: 40:09

That's kind of what this is doing for their pedal stroke. It's looking at the, the power that they're creating at different points of their, of their stroke, and it's saying how can we exactly match, um, the leverage that we're giving that particular moment of the stroke to the output, so that the, so that, for, for an irregular input that this cyclist is giving, and that's tailored to the exact specifications of that cyclist? How can we make the rear wheel, the output on the other end of the bike, be smooth and continuous, right. So wherever they have the least power, they're going to increase the leverage and wherever they have the most power, they're going to decrease the leverage. And what that's going to look like is, at different points in your stroke, your ankle is making a different angle with your foot and your knee is making a different angle with your ankle, and et cetera, and so those are going to be fundamentally different powers at different points in your stroke.

Garren Miler: 40:57

That an oval doesn't quite capture the nuance of right. Because if you have an oval chain ring, for example, when you're just getting into your power stroke, you're going to have the same leverage as when you're just coming out of your power stroke. On the other side and those are not analog situations it's actually very different kinematics up your leg, and so what this is doing is it's even further refining that sort of smoothing function that we're getting between the chainring and the rear wheel so that you can get as close to a perfectly consistent output on the other end from an irregular input. And that's going to be when, especially when you're splitting hairs at the professional level. That's going to be different for every cyclist, given their dimensions, given the length of their linkages, the length of their legs dimensions, given the. You know the length of their linkages, the length of their legs and their thighs relative to everything else, the length of their feet and, in particular, how their muscles behave and how much they've tuned particular muscles in their legs.

Tom Butler: 41:54

This kind of customization you know of specifically looking at what is going on with the individual's pedal stroke and then tailoring this linkage you know, this part of the drive mechanism between human and bike to precisely that man. It just seems like professional was hurting me and not helping me. But I really couldn't find anything like that. But you know, again, I'd be interested to know why people are saying, yeah, that that makes no sense at all.

Garren Miler: 42:40

Yeah, that makes no sense at all. I mean, obviously there's a lot of money and prestige and et cetera in the upper echelons of cycling and they're going to do whatever they can you know, tooth and nail to get an advantage. So I think that if they're not doing something, if they are doing something, there is some defensible reason for that. But in this context I can't really think of what that would be.

Tom Butler: 43:00

Yeah, yeah, I am really glad that I took this dive into this and what you've said here has been very helpful because of the biopace that's on the track the old track we have talked about it and wondered about it, so it was really fun to do this. You know, little bit of a dive into this. I can't say that we thoroughly uncovered everything about this, obviously, but it was interesting. So here's what I'm going to do with this information. First off, there's the scientific evidence, and the truth of the matter is I don't feel like there's much that's useful as far as the study is done for where I am as a cyclist. The studies were done to evaluate this for pros and for elite performance. They really weren't done on someone who's you know in their 60s that getting back on a bike after a long time being off a bike and kind of what my physiology is like. So I would need to see, I think, science done at that level for it really to apply to me.

Garren Miler: 44:15

Yeah, and I think that highlights another difference between professional cyclists and amateur cyclists, and that's that professional cyclists are going to be a lot more consistent person to person than amateur cyclists are going to be.

Garren Miler: 44:26

If you look at them all riding in the Peloton, they all are producing about the same amount of power and they're all riding in about the same style, at the same pace and they all have about the same capacity and capability to ride a bike, whereas if you take a cross section of a group ride in the city with everything from and we've been on group rides together, right, and I'm in my 20s and you're in your 60s and that's a very different cross section. So if you're doing studies on things, you're going to be looking at this really consistent group of professional cyclists, because then you can apply your findings more broadly across that group. But if you're looking at the the wednesday night group ride, you know that's going to be a varied bunch and so obviously the science is going to be geared upwards. But in reality everyone's really different and it's going to have a different needs and a different reason for making a setup that works for them.

Tom Butler: 45:11

And then there's the whole aspect of subjective versus objective performance. There's the scientific evidence and again I don't know that that really applies a lot to me evidence and again I don't know that that really applies a lot to me. And then there's the, you know, when I rode, I liked it. When I, you know, way back when I used Biopace, I liked it, and I think the aspect of whether or not I feel more comfortable if I'm riding a non-circular chain ring, I think that's as important to me as you know about anything. I don't want to have more knee pain, and so you know there would be that aspect of it. If I started experiencing more knee pain, then you know I would switch back, but at the same time, you know there is a role for what I would observe using it.

Garren Miler: 46:07

You know, when you think about cycling as a lifestyle, you start to think about what it means to ride a bike every single day, repeatedly, over and over again. I commute to my job on my bike, right, so I spend around an hour a day on my bike. And when you're thinking about the longevity of your ability to ride your bike and the health of your body, if I'm doing this every day for 40 years in my career, I need to start thinking about okay, maybe even a very marginal improvement on the comfort of my knees could pay dividends by the time I hit 60. Comfort of my knees couldn't pay dividends by the time I hit 60. And it starts now for me. And so if I can have global chain ring and it doesn't feel different day to day per se, but over time that marginal improvement adds up just a little bit, that could be huge for me, even if I never am on the circuit, you know, riding the Tour de France.

Tom Butler: 47:00

It'd be very interesting to know how many pedal strokes, how many revolutions you're doing a year. You know if there's even a little bit of difference when you talk about those linkages, if there's a little bit different level of exertion or level of friction or whatever, in that you know each pedal stroke, then that's adding up massively over 20, 30 years. Oh, absolutely, yeah, you know. Another thing that I think about is that it's pretty hard to quantify performance gains accurately for me. You know, there's so many things that can change from day to day. My climbing looks like, or whatever that it feels like it's going to have to be a subjective thing, because there's just too many confounding variables in the picture. So I'm pretty comfortable, I think, looking at using a non-circular chain ring from a subjective perspective.

Garren Miler: 48:11

Yeah, absolutely. And I think that to understand the non-ovular chain ring, it's better to look at it less from a performance perspective but more from an efficiency perspective. You're not necessarily trying to make yourself go faster or climb that hill better, but from a lifestyle perspective you're just looking at increasing the efficiency of how you're interacting with your bike, so that you're not pushing yourself so hard to get where you're going or to go on those group rides or to go have fun with the family. And I think a lot of it too is just psychology. I mean, if you think you're going to perform better with a certain part, maybe that makes a difference for you.

Garren Miler: 48:44

I know for me, for example, when I, when I snowboard, I always ride what's called a true twin snowboard, so both ends of the snowboard are exactly the same. Because if I don't ride a true twin snowboard, I just feel in my head like like something's asymmetrical and it's just. It feels wrong to me. And so if I ever switch the board around and ride the other way, it just I, even though I would never know the difference on a directional twin snowboard, it's just say I can just feel it in my head. Oh, it's not quite the same. I know for some people that the circular nature of their chain ring, they might want that, they might want to think. You know it's a circle and I know what to expect and it's consistent and you know and I know what's going to happen.

Tom Butler: 49:26

I think that's an excellent observation because, again, if I'm going out there thinking that something is benefiting me or slowing me down, you know I'm going to feel that. You know, regardless whether or not that's true, I'm going to feel it. We had someone one time that was talking about that. You drag them down when you're, when you're drafting off of them.

Tom Butler: 49:54

They were convinced that when you're drafting off of them they were convinced that when you're drafting off of them, you were pulling them down and they criticized one of the people that were riding with us for slowing them down by by drafting. And I'm sure, as they were riding and they noticed that someone was right behind them, they were feeling that in their mind, they were feeling that they were being pulled back.

Garren Miler: 50:19

You know they were so. They were so convinced of it that I actually had to look at myself, you know, does it actually look the one down? Is there something I'm missing here? Because they were so convinced that that that was.

Tom Butler: 50:30

That's what was happening I mean, when they first said it, I was just kind of like it took me a moment to really understand that they were saying that, hey, I felt you when you got behind me. I felt a drag on me when you got behind me, I don't know. I find that absolutely fascinating. But anyhow, it's just an example of what happens when you have it in your mind, if something's helping or something's hurting. And I think that's one of the things that I'm going to have to go into this, not knowing, you know, is this beneficial for me or is it not? Let's just kind of see how this feels, but it's going to be a very subjective thing for me.

Tom Butler: 51:09

I have decided to give it a try. Part of the reason is I'm not going to try it on my Roubaix. I'm going to try it on the FX3 because it's a one-by, and this is one thing that I saw a lot is that non-circular chain rings can cause problems with shifting. But when you have a one-by setup, you don't have to worry about shifting, you know. So you just get that one chain ring and, uh, you know, you're set, and so I think it makes sense for me to try that on that bike. And if you don't have a one by system, maybe it's not so interesting, but I but I'm going to give it a try yeah, I'm really excited to see how that goes for you what do you think about this concept of that it could cause shifting problems?

Garren Miler: 52:01

I think there's a lot of merit to that.

Garren Miler: 52:02

I mean, obviously, derailers are kind of precise instruments.

Garren Miler: 52:05

You know how hard they are to tune and to get right, and that's on a circle where everything's consistent right. But as soon as you introduce an irregularity to your chain ring, especially in a dynamic situation when you're pedaling, you always have the potential for the chain to jump around a little more. It might come off of the big ring at, let's say, a large part of the oval when it disconnects from that ring, and then you're still pedaling underneath it. So in that just brief moment that it falls to the other ring, that might be just enough time to cause some issues because you're now rotating a non-circular shape below it. That's inconsistent. So to me it makes sense that it could cause shifting issues up front. I think that what you're saying is totally right, that it makes by far the most sense on a one-by system and I probably wouldn't install it on a two-by system, just because there is that potential for for you know, having issues with that and also especially for a derailleur that wasn't specifically designed for that shape.

Tom Butler: 53:06

If I love it, if I put it on the FX and I love it, which is a possibility then I'm going to want to put it on the, the Rebay. But I think I'm going to have to find someone who knows what they're doing with oval train rings and say you know, what do I do about shifting? Is there a way to adjust the front derailleur so that you know, it's not a problem? So I think I'm going to have to get some consultation on that. It's not a problem, you know. So I think I'm going to have to get some consultation on that. Now the bummer would be if I, you know, love it on the FX and I talked to somebody like there there's no way you can put that on the on the Roubaix.

Garren Miler: 53:49

Right. I'd love to see that how that process goes of trying to get that to work well.

Tom Butler: 53:54

And then what do I do? Do I like go out and find the bike that it works on and, you know, sell the Roubaix, or you know what do I do? But that's a problem, yeah we'll have to figure that out. There's one more issue here, and currently on the FX there's a 40 tooth chain ring. I think this is a really interesting aspect of this and maybe you can describe this a little bit. But an oval chain ring is not consistent as far as the pedal stroke, like a circular chain ring would be.

Garren Miler: 54:31

When they talk about, say, a 40-tooth gear, we're talking about a standard bicycle tooth and what you're describing is the circumference of the gear, which is obviously directly correlated to its diameter. And so what you can think about, instead of thinking about the teeth count, you can think about the diameter count and if you know how big the teeth are, you can take the diameter and you can do some math to figure out how many teeth would correspond to going all the way around that gear, given the standard tooth size. So when they say that the oval chain ring is, say, a 42 slash 38 tooth, that's to say that at the biggest point it's equivalent to having a 42 tooth gear on, but at the smallest point it's equivalent to having, say, a 38 tooth gear on. And that's how they measure the diameter is in terms of how many teeth would be around the circumference.

Tom Butler: 55:20

So then, that you know, means what do you do when you've got a 40 tooth chain ring? What do you replace that with Absolute Black, which is the company that I'm going to go with. I'm going to go with Absolute Black. You don't want to have them tailored under your medical stroke. You know I am not finding out how much that costs, but I feel very confident that that's outside my price range.

Tom Butler: 55:49

It might involve a plane ride to Europe as well. Yeah, so, yeah, so I'm eliminating that as an option. But what they're saying is that a 38 slash 42 is best for someone who currently uses a 39 or 42 chainring, right Round chainring. Obviously interesting to me, because what that's saying is I'm going to drop down only a little bit where my pedal stroke. I don't have as much power, so I'm only dropping down two teeth. Yeah, I have less power and I'm only going up two teeth where I've got more power. That doesn't seem to me like a whole lot of difference.

Garren Miler: 56:40

Right, and I think that the difference is intentionally very subtle. I think if you got too crazy with that ratio, you'd probably start to feel really wobbly as you pedaled, and so I think that the subtlety is probably a very intentional outcome of this.

Tom Butler: 56:57

It seems to me like I would feel it more in a higher gear than I would feel in a lower gear. You know, when the rear chainring starts approaching the size of the front chainring, it seems like I would feel that difference less. And that's probably true.

Garren Miler: 57:16

I would feel that difference less, and that's probably true, I mean, especially when you think about like if you were to stand up and either sprint or climb, you're going to have that chugging motion already, and I think that when you're doing that kind of emotion, that's when you might start to notice a difference.

Tom Butler: 57:31

I actually had bio pace on two bikes in the past. I had it on a hardtail mountain bike that I had and the Trek 1500. And I stood up and I pedaled a lot on both those bikes. I never remember thinking I've got this like vroom, vroom, vroom, feeling to it where it's. You know, I can obviously feel where the difference is. So it's going to be interesting. I, you know, I've ridden a lot of miles now with a round chain ring and it will be interesting to see how much I feel it and I'll be reporting on it. I'll report on the process on that, on the weekly updates. Awesome, when I think about you know, 38 slash 42, the other thing I think about is I don't think I'm going to need a new chain, a rear derailleur adjustment or something, but I don't think I'm going to need a new chain.

Garren Miler: 58:21

Off the top of my head. I really couldn't do the mental math to figure out if that would. If you need a new chain for that, because it really I think depends on the tensioner on your derailleur and how, what the range of that tensioner is to absorb the extra chain. You know, if you have a lot of sort of spring left in that that you can eat up, then you might be fine. But if you're already kind of on the cusp then it might end up getting too much slack in it. I just I think it really depends on the geometry of your bike and I wouldn't know off the top of my head.

Tom Butler: 58:49

Here's going to be a fun aspect of this I am going to get the chain ring, take the chain ring and the bike into the Trek dealer. It will be interesting if they've ever dealt with that before and kind of what their whole, what their whole demeanor is. I don't think they would come out and say this was a dumb thing to do, you know, but it's very possible they could be like okay, yeah, we could do that if you want us to. You know, just kind of like subtly saying that they don't approve of this move. But you know, I think that they will be able to say, okay, you've got some slack in your chain here that'll have to be taken up, or whatever, and give some advice in that realm yeah.

Garren Miler: 59:41

So you've got me really excited about oval chain rings and you maybe want to run down to the store and buy one myself. But uh, the uh. The question I have, that is, how much does one of these things set you back?

Tom Butler: 59:51

yeah, that's a good question. They are not dirt cheap. I mean, they're going to set me back a bit. Now. There's a range of costs and I don't know exactly what chainring. I'm going to have to reach out to them and ask them which one I need for my setup, and ask them which one I need for my setup, but I'm expecting to pay somewhere around $80 for it.

Garren Miler: 1:00:26

Oh, that's actually a pretty affordable modification in the context of performance bicycling.

Tom Butler: 1:00:29

Well, again, I think if I buy into the notion that this is something that is going to make my pedal stroke more efficient and actually give me more longevity, reduce the chance. You know, when I did this right across Washington, you know, I ended up with bursitis really like killing my attempt. If I would find out and I don't know that there's any way to find this out for sure but if I would find out that this chain ring made a big difference with me getting bursitis, then it's definitely going to be worth that money. But I am committed to giving this a try and really seeing you know how it goes. So it's a, to me, a fair enough investment to make to do something like this.

Tom Butler: 1:01:14

Awesome, Garen, your comments on this were perfect. I just really appreciate you taking the time to have this conversation. I know that you're going to be following this with interest and I'll be really interested to see if you bite the bullet, if I find out that I can get them on the Roubaix, if you're going to bite the bullet and do that too. But uh, I'm excited to find out all right.

Tom Butler: 1:01:46

Well, thanks so much for the time and talk to you later yeah, talk to you later.

Garren Miler: 1:01:50

Bye, bye now.

Tom Butler: 1:02:00

I have a little bit more information to add to my discussion with Garen. I reached out to Absolute Black to find out what they would recommend concerning a chainring for my Trek FX3. Based on the exchange with them, I purchased their Cyclocross 1xOval 110x4 BCD NW Tr traction chainring. I got the 40 tooth size. The 110x4 BCD relates to the placement of the bolt holes and the NW stands for narrow, wide chain. I like the fact that it is a chainring tailored to cyclocross because I believe that means it is designed to be able to hold up in muddy conditions, because it's a more durable chain ring. It's on the heavy side but only at 65 grams and that's not going to be an issue at all on that bike. I called the Trek dealer about putting an oval chain ring on the FX3, and they didn't scoff at it at all. I will take the bike in when I get the chain ring because I want them to assess whether or not I need to do something different with the chain length. So it looks like everything is full steam.

Tom Butler: 1:02:58

Ahead for seeing how this works out and if I like it or not. This last week has been cold and snowy so I haven't been outside much. I'm getting a little nervous because, as I talked about in the update, I'm not getting a good enough workout on virtual rides. I have the 32-mile 2,100-feet Chilly Hilly coming up in a few weeks and I really need to get out and climb up some hills. It's awesome because chilly hilly represents the beginning of this year's cycling events, so I'm excited that it is only a few weeks away. Whether you are a few weeks away from better weather in your area or are going to have to wait longer for good riding conditions, I hope you're looking forward to what will make 2025 an awesome cycling year for you. And remember, age is just a gear change.