AJA#53: Pantani vs Pogačar, Hairy Arms, Navier-Stokes

Ask-Josh-Anything - Ep#53 - EPISODE TRANSCRIPT: 

Elden (00:48)
It's the Marginal Gains podcast, the show that makes a big deal about the little things and how those little things can be a big deal. We are brought to you by SILCA, which just makes really cool stuff. Like the Super Pista Ultimate, which is one of my five favorite worldly possessions, and the Omata, which I am extremely conflicted about.

Josh (01:07)
you

Elden (01:08)
I'm Fatty. This is the 53rd edition of our Ask Josh Anything episodes. I'm here with Michael Hotten aka Hottie and we have recorded

Darn near close to five hundred episodes at one show and another we were just talking about.

Hottie (01:22)
Mm-hmm. Mm-hmm.

Elden (01:24)
Feel like I'm getting to know you, man.

Hottie (01:26)
A little bit, huh? Plus I've I've stood in feed zones for you and handed you bottles and taken care of you and you know s yeah, we've done that. That's right. We

Elden (01:35)
And we have raced together one time in the Crusher and the Tusher.

Hottie (01:38)
did, yes. Yeah.

Elden (01:41)
All right. And of course we've got Josh Poertner, CEO of SILCA. You and I have never ridden together. What's up with that?

Josh (01:47)
No.

No. I mean we were like way over a hundred episodes in before we ever even met in person. Which just seems so weird. And yeah

Elden (01:54)
Yeah, I know, that is so strange. It

Josh (01:58)
I tell people that, and they're like, no, I just assumed you guys were like long-time buddies. Like

Elden (02:03)
Yeah.

Josh (02:03)
yeah no. Like, well, we had done a bunch of podcasts before we even started this podcast.

Elden (02:08)
That's true. On Cycling Tips Podcast, you and I had recorded numerous times together. It's it

Josh (02:10)
Yeah, and yeah, so.

Elden (02:14)
It is kind of funny. And what makes me mad is that everyone is taller than me. Just across the board. I find out whenever I meet people in person, it's like, man, another person who is taller than me. So, and I'm getting shorter by the minute. Guys,

Josh (02:28)
happens.

Elden (02:31)
I this episode I am going to blow your minds by not jumping the QA line.

Instead,

we're going to start this show with a listener question. This is a voicemail from Rusty in California calling the marginal gains hotline at three one seven three four three four five zero six (317-343-4506).

I love this question. I love the way it pits. I love the way it he is

Josh (03:43)
Yeah, yeah.

Hottie (03:41)
I love that he calls him Teddy.

Elden (03:48)
pitting marginal gains against doping. Although, of course, in both cases, there's an outrageous amount of accomplishment and talent. So Josh, this is a super clear cut, easy to answer question, right? There's no it depends.

Josh (04:01)
Right, right,

Hottie (04:02)
Mm-hmm.

Josh (04:02)
right. God, yeah, that's... Well, shoot, had I known this was coming, I would have sat with my model and done some math, but I didn't. For broad swaths, I'll say the top tires of today, like what Tadej would be riding, a GP5000S...

TR or TT, you're probably something on the order of 10 watts per tire faster than the tires of that era. Depending on how they were glued, you might be able to add another two, three watts to that. So I mean, could be 12 to 13. So call that at the high end, 25, 26 watts, just in tire.

Obviously, you've got aerodynamics. I these guys are fast enough that aero is a very real deal. know, just something like as simple as the bladed spoke, right? mean, that you can, that is measurable as, you know, 15 to 20 seconds of gain.

even on a climb like the Alpe d'Huez, right? The carbon wheels, the more aero frames. And we see the guys are, you know, 6.8 kind of helps with that, that the guys can choose aero because the bike weight is the same. Yeah, I mean, drivetrain friction, you can probably pick up another five to seven watts between just the improvement in the technology plus of the drivetrain itself, plus the improvement in the...

lubricating methods and advanced manufacturing, things like that. I think one of the big ones here that we often forget about, but is so huge was the clothing of that era was so bad aerodynamically. mean, so bad. I mean, yeah, just and

Elden (06:01)
Yeah, baggy.

Josh (06:04)
even at that level, right? I mean, it was it was just baggy and wrinkly and floppy and all the things.

And so those numbers are huge, even at the speeds these guys are climbing up to as in... You know, I think you add all that up. As I always say, I'm not a physiologist, so, you know, I have to call Alan Lim and ask him...

about the carbs and the fueling and all that stuff. But I will say at baseline, the thing that Tadej has going for him is, you know, I this is a kid that basically got pulled out of school for throwing down some VO2 numbers that, you know.

I mean, nobody says what the number is, but the estimates tend to give him somewhere between 94 and 98. People like to use 96 VO2 max as like the mid-range of what he's thought to be. But I mean, we know he was discovered literally as a kid as having a freakishly insane VO2 max. And I think Greg Lamond has talked about that a lot. Lamond was...

kind of the same way, except he didn't get tested. They put him on a bike and he just went out and started destroying people out of nowhere. you know, LeMond at his peak was like a 92 VO2 max. So I think that's another one to kind of really come at. You know, there have been some mid-high 90s VO2 maxes over the years. We've seen it in cross-country skiing. And so, yeah, that's where I, we should...

pull Alan Liman on this to kind of get his breakdown of the numbers of what's what. But I think, you when you put all that together, yeah, you start to approach the marginal gains plus just the sheer, I don't know, whatever you want to call it, the freakishness of Tadej as a human. Yeah, you can start putting down some numbers like that. But it is pretty incredible.

Elden (08:09)
So

I want to sort of do a reverse experiment on this. So you take Tadej and you put him in Pantani's kit and on Pantani's bike. How much slower does he go up the Alp d'Huez?

Josh (08:26)
I mean, he beats Pantani, right? I Pantani didn't have a 96 VO2 max.

Elden (08:32)
Mm-hmm.

Josh (08:33)
So yeah, mean, he, again, not being on the physiology side to break that into real power and torque.

But yeah, he beats him easily, right?

Elden (08:45)
Mm-hmm.

Josh (08:46)
So, you know, think, know, what Pantani had going for him, right, was his kind of strength-to-weight, you know, his power-to-weight ratio, essentially,

Hottie (08:54)
Yep.

Josh (08:55)
because he was such a tiny guy. But he, I mean, I'm actually, as I'm talking to you, I'm actually Googling here to see if anybody knows what Pentani's VO2 is; you can hear me typing.

Let's see if anybody has a, I'm sure people estimate this and we can.

Hottie (09:15)
Sure.

Yeah.

I'm Googling too. I'll do something else too.

Elden (09:22)
Yeah.

Hottie (09:23)
Wait.

Josh (09:26)
I'm not even finding great estimates of it.

But I think, and I'm trying to remember the strength-to-weight, but he was, I think Pantani, when you put it in power-to-weight, was in that six, seven range, and Tadej

Hottie (09:42)
Six six yeah, exactly. That's what I've got here, Ian.

Josh (09:46)
is at seven, and I think to me, that whole...

That whole doping era is so hard, right? Because you had such a combination of naturally gifted athletes who were on the cleaner side. You had less gifted athletes who were mega doped.

I was flipping Instagram the other day and came across, I always love to share with the young employees, that he had one of those like 80s and 90s cycling Instagram pages, but it was this awesome picture of Gert-Jan Theunisse with that giant headband that he would wear. know what I mean? This was a guy literally known to the other writers as Testo for his prodigious and open use of testosterone, right?

I think it's so hard to look at that era and really have any idea what was what because there were cleaner athletes and there were mega, mega dirty athletes. And I think everything in between. yeah, I think there's certainly some, know, was Pantani clean, far from it, but I also have it on good.

I would say authority from people I know who were racing of that era who were like, Pantani wasn't doing nearly what some other people were doing, right? know, how do you really know at the end of the day? But I will say, mean, taking, you know, of the modern, these writers of the modern era, the equipment they're on, the performances that you're seeing are, I mean, are just outstanding. And the...

people you know the Allen Lims of the world to I talked to in hangout with they're like yeah it's plausible right I mean some of this stuff he Allen was telling me the other day about some study one of these fueling things where they trained and there was like they were using I don't even know bicarb and something and something and heat train he's like yeah you know over like a month they found like a six percent difference in the group that went with it in the group that went without it you're like Jesus six percent that's,That's massive,

Elden (12:01)
Yeah.

Josh (12:01)
right? I kind of look at that and think of, like, nothing's going to get you 6 % short of doping. And you're like, yeah, no, the carbs. And remember, I was racing in this era. Like, we were starving ourselves. I mean, I was waking up every morning in France and having my cheek pinched and being told how fat I was.

Hottie (12:22)
Yeah.

Josh (12:23)
You're not allowed to anything. We were eating no carbs. We

Elden (12:26)
Mm-hmm.

Josh (12:28)
used to get just absolutely ripped up for eating bread or anything like that, because it would make you fat. Phil Gaiman, he's one who's talked really extensively on just the insanity and absurdity of that 90s era. So yeah, there's definitely an element of it too to think, gosh, what could some of the cyclists, what could a LeMond have done?

with some of the modern techniques, knowing that that guy was essentially a freak of nature of his era with this massive heart, these long femurs, this huge VO2 max, and the ability to suffer. He was a great champion, but shit, could he have gone two minutes faster up Alpe d'Huez? Probably. So.

But yeah, I'm just glad I'm not writing that because I struggled. Like my stomach cannot handle the carbs at all. And I get, I hear from people that it's better than it's ever been. But I mean, the thought of like that many carbs per hour for that many hours, I just think, my God, that would have been the end of me, I think.

Elden (13:45)
You say that, but it's not true. I am a normal person, but I have been able to train myself up to, you know, a hundred ink carbs per hour. Easily, I mean, we talked briefly about when I did the Everesting this

Josh (14:06)
Mm, yeah.

Elden (14:06)
last summer. Yeah, I was yeah,

I think I was at 90 to 110 grams of carbs per hour. And you know, just

Josh (14:15)
Wow.

Elden (14:16)
gel after gel for 18 hours. And it's not like I did that my first time, but I did it. I mean, you just yes, you have to train to eat the gels. And you

Josh (14:24)
So you're saying you did the training to eat the gels. Okay, I like it. Yeah, that's true.

Elden (14:30)
get and you do get so that you are better at it, just like every other facet of cycling. So you you could do it. That's all right.

Josh (14:34)
It's like drinking beer, you're saying. You gotta drink the beer if you're gonna drink the beer. If you drink the beer

Hottie (14:36)
Yeah.

Josh (14:40)
and you get sick, it's because you haven't drank enough beer to drink that beer, right? Yeah, okay, I'm down with that.

Elden (14:43)
So if you were to okay

so if you were to create somehow a true level playing field, all of the best cyclists from all of the eras, all on the same equipment, none of them doping, is there anyone who is better than Tate? Is there i or is he, as some people have said, truly the greatest who has ever lived? I mean

Josh (15:09)
Man, I...

Elden (15:09)
And this is for both

of you. I'm not asking just you, Josh. You're in the hot seat as well, Hottie.

Hottie in the hot seat.

Hottie (15:18)
Mm.

Josh (15:20)
He,

Elden (15:21)
Ha ha ha.

Josh (15:22)
we need a little bit, we need a little more time. I will say,

Hottie (15:24)
Yeah.

Elden (15:25)
Yeah.

Josh (15:25)
I I think he, I mean, it's him in my mind, it's him and Merckx taking all the other stuff out. I will say, and I've only known Eddie in my adult lifetime when he was retired.

What I will say and give to Tadej is he is one of like the nicest, not a word, the funnest, most like normal people I've ever known, like to be this high of a level in sports. Like he jokes, he's

Elden (16:05)
He's a lot.

Josh (16:05)
lighthearted. like, yeah, he's a different, he's like on another level to me in that way, right? It's like, I would say my experience with like,

the hardcore, like winning, you know, mean, even like Eddie to this day, and you see it in some of his comments about Tadej, right? I mean, like that dude's like, like he's ready to fight, you know, like, like, yeah, he's pretty good, but I was, you know, like better and like, I mean, I don't know, like Tade's just, I've never met anybody at that level, winning at that rate who's as chill and down to earth as, as that guy is. And

And as gracious and as, I mean, I don't follow baseball at all, but in my mind, I think of him as like, Tadej. You just see the stuff you see about that guy that he gets hit by a pitch and he's just like, hey, let's not, be chill, be cool guys or whatever. And again, I don't follow it. I just see the memes where I think, that guy seems pretty cool. But Tadej is legit, just sweet and funny and cool and easy and...

Yeah, I just can't think of it. you know, I knew Lance as a junior and then worked with Lance when he was winning. you know, I mean, that guy was, I mean, he's never been, he's never been a nice guy or an easy guy or, I mean, nothing about it, right? And some of that you get, I mean, I think I've told this story here before, but we went to, we were Texas A wind tunnel and we ran to Subway to get something to eat in the heat. That poor dude just got.

flipping mobbed at a subway. And you know, that was kind of my first thing of like, yeah, no wonder he's cold shoulder and like, I don't want to talk to you and I don't want to go places and I don't want to do things and I, you you're like, you build a wall around yourself, you know, and then, yeah, I mean, you go to a team camp or a tunnel test or whatever, or a tire test with Tadej and holy shit, he's just like.

He's like one of the staff. He's just so cool. I would say I give that guy just mega, mega credit for being that way. If you follow him on Instagram and you see him riding around with a giant baguette in his pocket or doing wheelies or giving his sunglasses to kids or whatever, in my experience, that's just how that guy is all day, every day.

Hottie (18:36)
Yeah, it's it's funny you bring up

Shohei Ohtani, Josh, because I was gonna say that baseball's having the same argument, the same discussion. I I'm not really an argument. Well, it's an argument right now, and that is is Shohei Ohtani the greatest player of all time? And there seems to be a rush, and this happens in sport quite a bit, to write history before history's ready to be written. Like Shohei has got career left. Like, why are we trying to say he's the greatest when he's still got time left? And

baseball has hundreds of years of history like cycling does that that have gone on you know, before it. So

We we can wait to say if he's the greatest of all time. I'm talking about Tate right now until Tade's, you know, done, maybe. Maybe that's the time to do it. It's not we don't have to do it now. We don't w there's no reason to be in a rush to write the history books, right? So I I I think

Josh (19:31)
Yeah.

Hottie (19:31)
I'm I'm on Josh's side. I mean it comes down to Tadej and and Merck's at this point, and then we'll see him with Shohei, it comes down to Shohei and probably Babe Ruth. So but we'll have to see. They were both two-way players and I think there's time will tell. Now on sho one note on Shohei.

Johnny Josh, it's kind of interesting as a narrative is starting to develop that he is a selfish player. Like he puts personal goals sometimes before he the team goals. So that's something that's starting to stir about him a little bit. It's on the negative

Josh (19:59)
Yeah, interesting.

Hottie (20:00)
side. He wants to like accomplish certain things and and Pogachar is obviously he has personal goals as well, but they generally revolve around the team, right? The team benefits as he benefits.

I is he is there I don't think there's a narrative that he's getting in the way of other writers so much. What they wanna do? I guess we'll have to see on that.

Josh (20:19)
Hmm. Yeah, I probably a little different in cycling where, you know, the team is built around him winning. Right. So I mean, there's that too. You know,

Hottie (20:26)
Right. Yeah, yeah.

Josh (20:27)
He, he, he's likely the greatest writer. But I mean, you look at that team, I mean, it's, you know, him getting injured this year. You're like, like, God, like, that's a huge loss. But then you look at what's left of the team. You're like, yeah. And you now have five other guys who can win stages and maybe an overall or jerseys

Hottie (20:44)
Mm-hmm. Yeah.

Josh (20:45)
or whatever. mean, yeah, you.

I mean, certainly I think he's the current best overall rider in the current best overall team, you know, and so yeah, he's got that going for him.

Hottie (20:59)
Yeah.

Josh (21:01)
you

Elden (21:01)
No, yeah.

Josh (21:02)
know, that never hurts. but yeah, the numbers,

Elden (21:04)
No, it doesn't matter.

Josh (21:05)
I mean, the numbers the guy can put down and everything else. mean, it's yeah.

Hottie (21:12)
Okay,

marginal gains also supported

Josh (21:13)
Not bad.

Hottie (21:14)
by Shimano, part of the allure of Paris-Roubaix one of my favorite races, one of Josh's favorite races, is the very unique one-off bike setups. this year there were a number of Shimano teams that went one-by-gasp. Yes, one by Shimano during a road race. It is a thing. Does Shimano have a dedicated road one-by group? No. But can you mix a GRX or XDR Dura-Ace with a pair of Dura-Ace shifters?

Sure you can. The bike tech press made this out to be some kind of great revelation. Fact is this kind of thing could be done way back in the early days of DI two. With wireless, it's just easier now. And now it's something Shimano actually acknowledges as an option, which is great. Will it end the grumbling about Shimano's lack of a dedicated Dura Ace? One bike group said, we doubt it. But if you'd like to part one out, go for it. And you can start by going to bike.shimano.

dot com. Okay guys, let's head down sciencey math road, if you will. Now, look, I get a little lost in this world, and this question is something I decided we should pose to Josh and see if there's anything here. My narrative here, Josh, is just it's just me reading some research I did. I really don't have any in-depth knowledge on this, but I wanted to just

Put

this out there and see if it makes any sense in the world of CFT and CDA and your world of engineering bikes, especially aerodynamic. The topic is Navier-Stokes. And the fact that OpenAI has said that its newest model has solved one of the great unanswered questions in mathematics, and that is the

Josh (23:00)
Hmm.

Hottie (23:02)
Navier-Stokes existence and smoothness problem. Now, Navier-Stokes equations govern the flow of fluids like water and air.

Engineers use Navier-Stokes to calculate surface pressure distributions and shear stresses. The equations were written in the nineteenth century, but understanding them remains minimal. While routinely used for weather forecasting and by flight engineers, the equations are not guaranteed to describe all possible conditions. Mathematicians have spent decades trying to prove the accuracy of Navier-Stokes or its shortcomings.

And that's why solving Navier-Stokes has been on the list of Millennium Prize Problems. When word started brewing that an answer was getting close, OpenAI threw a bunch of its agents on it and this summer declared victory. OpenAI's findings are that Navier-Stokes can sometimes get it wrong and produce unphysical solutions like fluids moving at infinite speeds, and nothing moves at infinite speeds, not even light. So, Josh.

Did I screw up anything here, first of all, in this little narrative? And does Navier-Stokes play any role in your world when calculating C D A or using C F D or otherwise?

Josh (24:14)
Yeah, mean, this is a big one. And I will say, I'm a math kid, not a math adult. So

Elden (24:24)
Yeah.

Josh (24:25)
I have deep familiarity with the Navier-Stokes equations. I am just old enough that we would have to like hand solve them in like matrix form.

when I was in school, which, know, there are these crazy equations and like multiple, you know, God, you can't even get at it. Like you have to solve them in X, Y and Z and then you're solving them over. Holy shit, these things are wild. Yeah, most modern CFD basically is just solving the Navier-Stokes equations over and over and over again at, you know,

thousands, if not hundreds of thousands or millions, of points, and then you're solving them essentially in time steps to predict the fluid flow, right? So you're trying to solve at all these points to look at the current state of the fluid and then you're trying to like predict the next Place the fluids gonna go. So it Navy Stokes has always been this really kind of brute force Just big gnarly Equation set right? It's not one equation. It's a set of equations

A lot of what's going on here is that we, and part of what the Millennium Prize is, we still don't, and I think we've talked about on this show before, there's a lot we don't understand about turbulence. We don't really understand why laminar flow transitions to turbulence. We have a bunch of different equations that try to predict that or...

And some of those can work in specific situations. And so like you're talking to somebody who's a big CFD user and they might say, like I use this turbulence model for automotive and then somebody who's doing aircraft will use a different turbulence model and somebody who's transonic will use a different one and somebody who's using supersonic is in a different, I mean, there's.

there's still a lot that's unknown. And so, yeah, I've read a little bit on this because I thought, this could be so cool if AI has really done this. what I will say from the people I have talked to in the CFD world, they are still pretty skeptical. And apparently the quote unquote proof, the paper that OpenAI dropped, you know, kind of claiming to have solved this is pretty brutal even for like

the most serious mathematician. I think the current I cannot remember the group there's a group that kind of audits the Millennium Prize and I'm just blanking on their name, but they've come out and said that they it'll likely take two years

Hottie (27:05)
Mm-hmm.

Josh (27:06)
to figure out if this if if the proof is a real proof or not,

Hottie (27:09)
Mm-hmm. Mm-hmm.

Josh (27:11)
and if it's true. Yeah, so mean, I think that also then speaks to the like,

just the sheer heaviness of how complex this is, right? It's not like two plus two equals four and like, we gotta prove that now and

Hottie (27:26)
Ha ha ha.

Josh (27:27)
we can go, you know, and I was never a fan of mathematical proofs personally, because that's just, my brain doesn't work in that way, but yeah, it'll take the best mathematicians in the world two years to prove if this is correct. That gives you an idea of the...

complexity, shall we say, the scale of the complexity,

Hottie (27:48)
Yeah.

Josh (27:50)
is

Elden (27:49)
They should just ask Claude.

Josh (27:51)
mega. Yeah, I mean, that would be the other way, just to say, know, I mean,

Elden (27:53)
Yeah.

Josh (27:55)
it kind of reminds me of my one of my favorite current kind of popular types of meme, which is, know, like the guy's in his garage and he's like got the engine of his car like up on the hoist and it's the the chat GPT voice going I'm sorry you're right you don't have to remove the engine to change the battery in a 93 Honda

Elden (28:12)
Mm-hmm.

Hottie (28:12)
Ha ha ha.

Josh (28:14)
Accord like like

my god, like because that anybody who's

Elden (28:18)
That's on me.

Josh (28:19)
using any AI that's pretty much the story of your life, like

Hottie (28:23)
Well, if

OpenAI has got it right, and there are problems with Navier-Stokes, that it produces unphysical solutions, what does that what could that mean for you or the bike world or anybody working in CFD? What could that mean?

Josh (28:38)
I mean, I think the thing that could be the most meaningful here is you take like, so, you we talked with Ingmar Young-Nickel at IRO, right?

Hottie (28:49)
Mm-hmm.

Josh (28:49)
And, you know, they're basically making a model of your body and then doing like a heavy, heavy compute on the flow around you. That's all Navier-Stokes, right? And

Hottie (29:03)
Okay.

Josh (29:04)
so each, like each...

each point in the flow is three big Navier-Stokes, it's the set of equations, right? So you have to solve this big complicated equation where you know, accurately know the incoming, you know, they're basically, it's like vectors, right? So you have to know, like, kind of the vector directionality; you have to know the magnitudes; you have to know all this stuff.

And so you're solving that in like hundreds of thousands of points over and over and over again. I think there's some hope that you could simplify this if you had all the pieces, right? So think there's sort of a belief that like the Navier-Stokes is incomplete. And I think one of the things we can comfortably say like there's incompleteness to it is that you can...

come up with solution sets when you do them that lead to things like that, that you're like, okay, well, that's clearly not possible. So it's a little bit like where we are with physics currently, right? We can solve pretty accurately in the quantum realm, and we can solve pretty accurately in the physical realm, but we can't connect them yet. Some of the hope is that we'll be able to connect from the pre-turbulent to the post-turbulent and understand this trans-turbulent.

kind of flow area. But I think also there's huge hope that if you really had all the pieces, the set of equations would simplify and that would reduce the compute time. And if you reduce the compute time, then you can solve for more points. you know, like a Formula One car when they're running CFD, you know, they're using like

tens of millions of points, if not hundreds of millions of points, and they're taking tens of thousands of cores of compute to get there. The hope would be, and I would say typically at the pointy end of Formula One and some of the stuff that's happening in cycling, you're limited by your compute, which is a little bit like where a lot of this AI stuff is at the moment. Maybe that's limited by training, but you're limited by compute. And so the hope would be if you could...

make the equation more accurate, maybe simplify it that maybe you could do much more on the same amount of compute as you could do before. And that would take away a little bit of the, like in F1, right? Forever, when I was working with Matt Godot and Star CCM Plus and all those guys back in the day, they had Red Bull as a customer and Red Bull's initial mega success was that they built far and away

the best CFD computer in all of Formula One. And this thing basically was like a giant indoor refrigerator, I mean like multiple basketball courts in size where the floor was just covered in thousands of GPUs. And that just allowed them to have a level of compute that none of the other teams had and so they could refine their models and then they could...

They could just work at a much higher level of complexity. So I think that's the ultimate goal here would be that we could work at much higher levels of complexity with, I would say, the side benefit being that we would much better understand these transitional phases in the flow, like why the turbulence starts, where it's going to start, what's going to happen downstream, and then be able to use that same set of equations everywhere.

rather than having to change it as the fluid regime changes. If

Hottie (32:45)
It would

Josh (32:45)
you're modeling a rocket launch now, you're using different turbulence models as that thing is mostly laminar to transitioning to turbulence and then all the way up to the transonic flow regime. Now you've got to change that model. Once you're supersonic, you've got to change the model.

of turbulence again, just stuff like that, right? That in an ideal world you'd be like, yeah, here's the one equation and it just works everywhere.

Hottie (33:16)
Hm.

I don't care about any of that. Well my wheels roll better through air. My bike wheels, that is. Right? Could it mean that, possibly?

Elden (33:20)
Ha ha ha

Josh (33:20)
Yeah, yeah, possibly.

I would say it depends.

Elden (33:25)
It depends.

Josh (33:28)
I mean, honestly, I think we're at a spot where we have done so much. I am not going to say that there's not another like blob of solution sets out there for wheels that are unlike anything we have today. I will say, you know,

There's this sort of like thing, it's like the annealing model where like you have different like solution sets kind of occur in blobs and they're not necessarily connected to each other. And I think we've talked about that in, you know, wheel aerodynamics, like forever wheels were pointy and were like NACA shaped. And we really exhausted that whole blob of solutions and we couldn't make it much better. And then, you know, with like toroidal, you were able to do a bunch of stuff around that and that was pretty cool. But then

Like when we did the firecrest thing, that was like out of left field, right? And that solution was not really connected to any of the other solutions prior to it. And so I think that would probably be a good kind of example there of, like, but you know, it's not like if you keep refining the Firecrest shape, which is pretty much what every modern rim shape is, you know, plus or minus.

It's been so refined that I don't think there's any really refinement. It's why the wheels are basically all the same anymore. You're not gonna continue to refine that and then all of a sudden have a breakthrough. And so if there's a breakthrough to be had, it's gonna come from something that looks totally different that's weird. And so is that possible? Yes. Is it likely? I would say no.

But having something like, well, and then the flow regime of cycling is controlled, right? If this was like dragster bicycle, you know, and we were going from zero to 350 miles an hour, we would have other problems. But since we're kind of in the same flow regime that we've always been, you know, you can chip away.

You can chip away at a huge, huge percentage of this in a wind tunnel with clay. And ideally, if something like this happens, compute costs keep coming down. It will become a brute force thing that maybe you just throw millions and millions of computer-generated rim shape ideas at it. Maybe we find another blob of solutions out there somewhere. But my gut is...

unlikely but you my gut was also said it was pretty unlikely when we discovered the Firecrest thing you're like shit that looks weird and

Hottie (36:13)
Mm-hmm.

Josh (36:15)
and kind of awful i mean honestly we hated that at first

Elden (36:18)
Yeah.

Josh (36:18)
i mean we we kind of discovered that and we're like how the hell are we going to convince people that this works because that looks dumb you know like right like let's be honest this looks stupid nobody's going to want to ride it and

Hottie (36:23)
It did look weird. Yeah, it did. It does.

Josh (36:31)
yeah you know here here we are so yeah there's

Maybe there is another one of those out there and if so, maybe this could play a part in finding it, but unlikely.

Elden (36:41)
And I do and

and I do want to stay on AI or go back to AI for a second, Josh, because in my own life, I have a pretty good idea of the pros and cons of AI in my job. You know, in software development as a consumer, you know, the way that I use it, the way people around me use it. But I've been curious how it is affecting

Company like SILCA because of course you're a full-spectrum business. You design, prototype, test, produce, ship, store, sell a huge range of products all around the world. And now, of course, you're creating a lot of content to, you know, grow awareness of those products. And of course, you're just a curious person in general. So net it out for us. How is Silca using AI? And how is AI impacting Silca?

Josh (37:35)
I mean, at the moment, honestly, we only use it internally as a note-taker at this point.

Elden (37:42)
Really?

Josh (37:43)
Now we started, I think I was interested in the front end. I had a couple of employees who were super into it at the front end and I would say if I had to...

this is, I'll put a timestamp on it, this is October 2026. I think AI is in its internet 1.0 phase. And I think that's probably true for the tech. We're at like pets.com version of AI, and I think it's also, I think it has to be true for these stock markets. mean, this bubble's gonna collapse now, not to say that AI's not gonna be the future, but.

I think we're definitely at, I'll call it the bullshit phase of the technology, right? It's a bunch of people talking a bunch of shit. And, you know, does some of it work? Yeah. mean, can you, you know, are people making porn with it? Absolutely. You know, but, you know, our experience really turned out to be like, we tried to build, which I think was kind of cute, but the customer service tried to build what they were calling virtual Josh.

And it was like all of my technical responses to customers and email, all of the stuff I ever wrote on SlowTwitch.com. They tried to feed in all the Marginal Gains podcast stuff. And what we saw happen, and this was a year ago, maybe as the tech changes, maybe it becomes different, but it actually started out okay. And I would get all the responses.

and you could grade them, you know, like to train it. And you're like, that's not bad. That's pretty good. I'd say this this way. I'd say this that way. And honestly, the more it interacted with people, the dumber it got. And it just started talking bullshit, like nonsense. And it started saying things that made no sense at all, out of nowhere.

And so we shut that down. We had a couple of terrible consumer interactions where people are like, yeah, I asked your chat bot this thing and I got, look at this answer. And you're like, my God.

Elden (39:52)
Yeah.

Josh (39:54)
So yeah, I don't know. I would say I've become much more skeptical of it now than then. We use it as a,

I think the sales guys have this thing, what's it called, like a plod. It's like a little recorder that sticks to the back of your phone and you're in a meeting. It takes your notes and you can say, hey, give me, yeah, like summarize

Elden (40:15)
Sure. Record, transcribe, summarize. Right. Mm-hmm.

Josh (40:19)
and give me the action plans and from who. we had a group that's in...

Taiwan with a supplier right now, actually with a tire supplier. And they've got it and it's pretty awesome. It translates the Mandarin being spoken in the back end. And so you get the notes, but you also get like their side conversation. That's pretty phenomenal. But then...

Elden (40:46)
You're not

using it for engineering. You're not using it for prototyping or for testing or for cad work or anything like that.

Josh (40:55)
No, and not for lack of trying and experimenting, but it's just not good. And that's where I have to say, like, I'm not saying it doesn't become good,

Elden (41:06)
Right.

Josh (41:07)
but at the moment it's... I mean, I'll tell you, the final straw for me was... Gosh, this is probably a quarter ago.

Yeah, this probably would have been like the end of the second quarter, July. We do cycle count. You know, so in the warehouse and we have six, seven warehouses now, you cycle count your A items get counted every month, your B items get counted every quarter, your C items get counted twice a year. And so July is our overlap where everything gets counted. And so we do this huge count, all these employees, it's all on paper.

And typically you would sit and transcribe that in and you know it's hours and hours of work for somebody because we have you know 400 SKUs and another I think 400 finished goods SKUs we have something like 6,000 subcomponents and you have to all those counts in all these locations

We feed it all into the latest and greatest, the July ChatGPT, and we have like a 9 % error rate. And when you're auditing for the error rate, I'm thinking, well, handwriting, you know, whatever. Yeah, no, it's transcribed like 173 as like four. Like, fuck you, ChatGPT. Like,

you can go to hell. that's not, you know, I I expected it to be like, your seven looks like a two or vice versa or some whatever, but like four?

that, you know, come on.

Elden (42:36)
Just getting things wildly wrong.

Josh (42:38)
Yeah. And so, you know, and so now it's like, well, shit, spent the time it took to do that. We spent the time it took to figure out why it was so jacked up. And then we had the time to do it how we would have done it to begin with, by hand in the first place. You know, and that's that's not. Chachi, you know, open a I one point, right, that's open a I.

don't know, whatever it is now, they're, it's exponential learning and all this stuff. So with that, I'll say the other, I'm in a few of these entrepreneurial groups and you talk to people and everybody I know in business is basically saying the same thing and then you see these great reports that are, Microsoft said that 89 % of...

offices are leveraging the whatever and then you know there was another one that actually came out in one of the business journals that was so funny it was like 93 percent of office managers said they felt pressure to say they were using AI successfully in surveys I'm like, yeah I know

Hottie (43:40)
Ha ha ha

Elden (43:41)
Ha ha ha.

Josh (43:43)
they do right I mean we I've had that conversation with my employees where they're like hey I you're paying money for this thing and I feel like I should be using it but it doesn't work

And so if I also had to put numbers to it, would say, think at the moment, it's a big scam. And I say that because I have to say scam every once in a while because it gets attention. But I do. I think we're at the pets.com phase where it's going to blow up and everybody's going to be like, see, we told you bullshit. It was a scam, the whole thing. And then the next generation.

eventually, you know, we're going to be where we are today. We're like, yeah, I only buy my dog food on Chewy. Right. It's like Pets.com was insane, but like Chewy. yeah, we all use Chewy.

Hottie (44:31)
Mm-hmm.

Josh (44:32)
Right. So I have little doubt that that's the future. But I think at the moment it's

Elden (44:39)
It's not the present.

Josh (44:40)
and quite frankly, I mean, I think that the sad thing about it is what it's really good at is all the shit that's going to just fuck the world up in terrible, terrible ways.

Hottie (44:47)
Right.

Josh (44:49)
Right? Like it is not good at transcribing inventory reports and it is not good at doing much that's useful, but man, it is fucking good at hacking into things and breaking stuff

Hottie (44:59)
Mm-hmm.

Josh (45:00)
and

Hottie (45:03)
Uh-huh.

Josh (45:04)
causing chaos. Like it's real good at that. And I think of the risk societally; it certainly worries me because you don't even need it to be malicious.

You just need it to be an agent of chaos. Right? And so I think you certainly have malicious people using it, but you read these reports, and I don't if you read the puggy face, I mean, that

Elden (45:29)
yeah.

Josh (45:30)
like, they teamed up, they got in, they jacked stuff up, they covered their tracks, they were, you know, I you can see it, you're like, holy shit. And again, it kind of doesn't even matter if it's malicious; it just has to do damage, you know?

Elden (45:45)
It's yeah, it's not

Whether it's malicious, it's more that it's indifferent to humanity, right? It's you know, it's like, hey,

Josh (45:54)
Yep. Yep.

Elden (45:55)
I created this novel virus. And it's like I wasn't really thinking about killing people, I just thought it was interesting.

So this episode turned dark.

Hottie (46:07)
Yeah, yeah.

Josh (46:01)
Right. Right.

Yeah. Yeah, yeah.

So there you go. you're

Hottie (46:10)
Let's get back to bikes

quickly. Goodness. Yeah.

Elden (46:13)
For now, sure.

Hottie (46:14)
How about a question here? from Grant in Maryland. He texted this into the marginal gains hotline, three one seven three four three four five zero six (317-343-4506). Thank you, Grant. You got us out of the dark side.

he says, I'm asking

Josh (46:24)
Yeah.

Hottie (46:25)
about aero gains for wearing long sleeves. I'm a hairy individual with longer-than-average arm hair. It's a lot of info, Grant. Would wearing a long sleeve

Josh (46:35)
Yeah.

Elden (46:35)
I hear you, man. You're my people.

Hottie (46:37)
Wearing a long-sleeve speed suit in cool conditions, short criteriums, be beneficial? I'm thinking about getting a TT suit for a KOM attempt on a flat, slightly downhill stretch of road.

Speed will be in excess of 35 miles per hour. I'm pretty disciplined on my road bike to hold the arms at ninety and pedal. Good idea or just a get a short sleeve. I know. We talked about yeah, we've talked about long sleeves and marginal

Josh (47:02)
Yeah, good idea. Yep, good, good idea. Good idea. Yeah.

Hottie (47:06)
gains before, Josh, but this is a good one. Like hairy arms. Like, do we try to cover that

Josh (47:09)
Yeah, yeah, yeah.

Hottie (47:12)
stuff up?

Josh (47:13)
Yeah, I mean, if you can handle the thermal management side of it, go with a long sleeve; otherwise, shave your arms. The other one I'll say, and I don't think we've ever said this on this show, I will, my friend is a junior, Jeff Breyer, who probably, I think, listens to the show. But he coined a phrase back in the day.

about when you have the hair that sticks out of your shorts and he called them pubescence because he said they're like pubic

Hottie (47:44)
Cool.

Josh (47:45)
debutantes, right? They're coming out. so there you go, pubescence, you're welcome.

Elden (47:53)
Haddie's going, do I keep this? Do I re-edit this?

Josh (47:56)
Yeah, exactly.

Hottie (47:55)
no.

Josh (47:58)
What's the plus-minus on leaving that in the show? But that is the question for the long-sleeve suit. I have had this discussion with, like, Tour de France champions. It only works if the hair doesn't come out the suit. And for some fabrics, it does, right? And especially the lighter weight, like the summer weight.

Long-sleeve TT suits and stuff, you may actually just be making yourself hot, and if you've got 10 % of the hairs sticking through the suit anyway, you've undone anything the suit is giving you as a benefit, and you should have shaved arms. So I'll leave it at that.

Elden (48:44)
I will add, Grant,

as another hairy guy, as long as you're shaving your legs, you got the razor out anyway. Go ahead and take care of your arms, and you will discover that suddenly your arms, your forearms look so much more ripped. It is just

really

Josh (49:01)
Ha

Elden (49:02)
awesome. So, yes, there is a placebo effect that is absolutely worth it. Double benefit. Yeah.

Josh (49:07)
It's like double benefit. There you go. Double benefit.

Double bonus.

Elden (49:12)
You're getting a nocebo effect with those hairy arms right now.

You don't realize how ripped your forearms are right now.

Josh (49:20)
You

Elden (49:21)
Aesthetic advice from a guy who used to be 5'7 and is trending toward 5'6. So okay, so I've I feel like I've waited long enough to ask my own question now. I didn't do this jumping the line, but I know you guys are both car guys. I'm not really, normally, but I'm very interested in what you think about that recent Tesla Roadster demo.

Josh (49:47)
Mmm.

Elden (49:47)
I I I

I'm not interested, really, from the Elon Musk politics point of view. I think most people's opinions on Elon himself are pretty baked, but from the engineering perspective, the interesting, as a technology perspective, why are they focusing on this wild roadster that will never possibly be on a freeway? From the easy part. Let's start with the easy parts. Josh,

Josh (50:14)
you

Elden (50:15)
what did you think?

I i w w it was this a cool engineering demo?

Josh (50:23)
It was a cool engineering demo, but I think to me sort of reeks of desperation. And

Elden (50:34)
Hmm.

Josh (50:36)
I mean, you know, guess you have to give it to not a fan of Elon at all in any way.

But you have to give it to him. mean, the guy knows how to put on a show. He knows how to get attention. He all that stuff. And yeah, I mean, the tech is really cool, right? I mean, they're able to leverage some of the propulsion knowledge from the SpaceX business to make a car jump up and do some party tricks, you know, like, yeah, that I mean, that's cool, right? But

Yeah, I mean, I would much rather the car they originally showed in what was it 2017 or something. There was a beautiful, well-designed car. mean, that car was pretty. This car to me looks

Elden (51:24)
Mm-hmm.

Josh (51:24)
like ass. It's like a bad kids version of a...

you know, if you had to close your eyes and be like, what did the Countach look like when you were 12? Like, yeah, you'd kind of get something like that, I think. So I'm not a fan of the design at all. I have enjoyed, there's a couple of YouTube videos of people kind of tearing apart, you know, when the thing is airborne, you can see it's just like a simple aluminum ladder frame underneath. mean, it's not a real car, right?

Hottie (51:52)
Yeah.

Josh (51:52)
It's a stunt thing meant for this show.

So there's that, that it's not... I don't want to hate on it too much because they made it do some cool stuff, but yeah, I would say not a fan.

Elden (52:13)
But it didn't feel particularly exciting engineering-wise or innovative, necessarily, even. I mean, we've seen we've seen cold gas propulsion before. We've seen a fan car before, right? I mean, it this is not the first car to stick

Hottie (52:28)
No.

Elden (52:30)
to you adhere to a surface while upside down, even.

Josh (52:34)
Yeah, yeah, mean, that's Jim Hall, right? Chaparral, 1970, like, with a fan car. So, you and you just don't see them because they're illegal. But I mean, you've got the modern Gordon Murray, who was the designer of the McLaren F1, but he's got his Gordon Murray Automotive or whatever it's called, but they've got multiple fan cars and the McMurtry Spearling, which is a pretty cool...

thing to look for, know, and the difference being, you know, quite frankly, that those things exist in their actual cars that people can drive. You know, so yeah, I mean, I think I think it's a it's a hell of a gimmick and hell of a, know, and I think I think it's so polarized anymore that like you're either a Tesla, Elon fanboy, and you're totally creaming yourself over this thing and you're going to put some money down.

To maybe get- you think of how many thousands of people put money down in 2017 for a Roadster, and it's nine years later, and they still don't have a car, right? But I mean, you look at it is kind of the history of Tesla. I other than, you know, taking lots and lots of government money and subsidies around clean energy and all that stuff. I mean, they've really cashflow themselves with.

down payments of people who, know, mean, how many thousands of Cybertruck people put money down and waited years and years and years for cars. you know, I think Elon being Elon, he can somehow go back to the well and like pull this stunt over and over again and get away with it. And people seem to give him a pass. I mean, I will say, you know, he generally, ultimately does pull off the crazy stuff he says he's going to pull off. And so, you know, I think you just need a...

enough of a track record of not totally screwing everybody to get past it. But yeah, I thought, you know, super fun, cool, gimmicky thing, I mean, not really relevant or realistic or there's just so much to me, so much more they could have done that was interesting.

number one, I think the number one most offensive thing to me is like, just actually make a beautiful car. You know, as a car guy, like

Hottie (54:50)
Yeah.

Elden (54:51)
Ha ha ha.

Josh (54:52)
just make a beautiful car. I mean, I kind

of don't, you know, I mean, we're definitely at a spot where, you know, like any average electric car, I mean, that little electric Kia hatchback will smoke a McLaren or a Ferrari or, you know, whatever, but like, that's not, like, that's cool, but that's not, you know, I...

I want it to look beautiful and go vroom vroom. I want to make noise.

Elden (55:15)
Yeah, being fast isn't enough, right.

Josh (55:18)
Yeah, okay, we've gotten so good at making it fast that your brain and your body can't react quickly enough to handle the fast, right? mean, there are so many cars on the road that are like, you can't extract 80 % of it because you're not a good enough driver. And so you're just adding more and more automation.

I definitely feel a little bit like they should take a lesson from Apple on this and just make a beautiful product that is desirable that people want. I love that about Steve Jobs and his thing of like, man, I'm not gonna talk numbers and specs and processor speed and all this other crap. My customer doesn't care. My customer wants a beautiful object that makes them smile and that works. I think...

cars are definitely at a level now where it's like yeah that's that's the standard i mean you yeah you give me 2000 horsepower and zero to sixty and 0.8 you can't use it, right it's

Hottie (56:19)
Mm.

Josh (56:21)
so

Elden (56:22)
I don't want to use it. Not when I'm on a bike.

Josh (56:25)
Right, yeah, yeah, there's that.

Yeah, that for sure. Yeah, I mean, again, I would way rather them have actually figured out self-driving, right? I you look at like self-driving, quote unquote,

Elden (56:34)
Mm-hmm.

Josh (56:34)
self-driving just continues to like kill people, especially cyclists and pedestrians, and crash cars like, geez, like take the money and actually solve that problem that you said has been solved over and over again for years. That's

Elden (56:52)
Mm-hmm.

Josh (56:52)
clearly not because we keep...

killing people. yeah, that would be a real thing. you know, that's one person's opinion. Mine.

Elden (57:02)
Yeah.

Josh (57:03)
And it's...

Supposedly. don't know, what do need to say legally so that Elon doesn't come throw shit at me? Allegedly. Yeah, allegedly. Yeah, that's

Elden (57:11)
Allegedly. There we go.

Hottie (57:13)
Allegedly, that's it.

Josh (57:15)
one, allegedly my opinion.

Hottie (57:17)
Yeah.

Okay, one more bike question, maybe. how about why does carbon break? You know, back in the world of things that existed and could be purchased, Peter in Minnesota has a carbon question. He texted into the marginal gains hotline, which is three one seven three four three four five zero six. How come my daughter hits many fifty-mile-per-hour softball pitches with her carbon softball bat, and her bat is fine?

My son takes many slap shots with his carbon hockey stick and his hockey stick is fine, but if I bang or crash my carbon bike frame once, it breaks. It seems carbon behaves differently in different contexts. The bat pops, bends inward slightly before springing out, the stick flexes, bends back, then snaps forward. But the bike breaks. Why? Do the objects contain different carbon material or weave? Is the resin or epoxy different?

Like the bike, the stick and the bat can both break if used improperly, and like the bike are expensive or impossible to repair. Look forward to your response.

Elden (58:26)
I love that he asks and then answers this question more or less.

Josh (58:32)
Yeah, I mean, you sort of answered it. It's because crashing it is something it is not designed to do, unfortunately. yeah, I could you make a carbon frame where, say, the top two was laid up like a bat that it could handle a massive impact?

from the side, you absolutely could. Would it add 150 grams? Yeah, it absolutely would. And then it just becomes the issue of like, who's going to buy it? You know, there's kind of like anything that we're engineering out towards the margins, right, of the marginal gains. You start to run into these things where it's like, well, we at some point have to choose.

performance characteristics and you know I mean we've even seen climbing bikes out there I think Merida had one and I think a couple of companies had them in the last few years were like you it came with a sticker on the top tube that you couldn't sit on the top tube because it would break and so you know top tube is essentially an element of the frame that's meant to really handle tension and compression only you know it needs a little bit of lateral stiffness

to help reduce speed wobble and ideally it probably has a little bit of compliance in the vertical direction to kind of help reduce vibration transmission through the And to meet all of those you can build that tube in a way that it can...

do only those things, it really is the beauty of carbon, right? You can lay down reinforcement specifically on exactly the axes that you're worried about. And you can do it in a way that you just enough translation of forces between plies to kind of smooth that load that it can handle some of the somewhat off-axis loading that it's gonna experience.

But yeah, you have nothing in there that's gonna handle something like a softball impact at 50 miles an hour, less, much, much lower speeds. And so...

Hottie (1:00:53)
How about the fork though? Carbon forks

put up with a lot, it seems like. Like I've rammed those things hard and they've come out I mean, I I don't know for sure, but they look great. And it looks like 'cause they're just bulked up.

Josh (1:01:03)
Yeah, so carbon

fork is a great example of something that sees so much stress that the laminate has to be built up in ways that you can end up with significant impact resistance on accident.

Without designing it in, it's just there because you think of what the fork is under, like it's bending out forward from underneath you under normal riding conditions, and when you're hitting bumps and things, right, it's gotta handle those impact forces. Then you hit the brakes and it's violently yanked backwards, right, so you're like completely reversed loading the thing.

when you're out of the saddle or sprinting, it's got to handle these really big lateral loads. And then of course, it's got to handle all those things combined where you can be out of the saddle sprinting and the bike is going side to side while hitting bumps or potentially breaking. And so, yeah, so something like a fork, really, I hate to say on accident, but yeah, you can almost build in a high level of damage tolerance.

Elden (1:02:11)
As a side benefit, yeah.

Josh (1:02:11)
without actually, without,

yeah, without trying for it. But in a lot of the rest of the bike, yeah, I mean, you're, you know, the reality is whether it matters or not, we all still count grams and the frame makers and the bike makers still talk grams and that's a selling point and the more expensive a bike, the lighter it's expected to be and so that weight has to come from somewhere. And that, unfortunately,

Well, unfortunately, when you actually crash the thing, that comes from removing material that would either have been designed for something like crashing or would have maybe, say, added stiffness in some other way, but would have thickened the laminate by another layer, know, another ply of thickness that would add to its ability to handle something like an impact. yeah, it's...

Elden (1:03:04)
Are the materials

more or less the same, however? I mean it's or are the materials also different? Like are he was asking about the resin. Is it a different kind of resin that you might use in a bat or a hockey stick? Different than what you might use in a a road bike or even a mountain bike?

Josh (1:03:23)
Yeah, so the and I don't know the current state of bats or hockey sticks other than I do know my my patent attorney, his son is a college hockey player and he says he goes through like 10 to 12 like $500 sticks a year. So I've always kind of thought

Hottie (1:03:41)
no.

Josh (1:03:42)
like, man, why aren't we in the hockey stick business like that

Hottie (1:03:44)
Right.

Josh (1:03:45)
sounds. But

Because those are essentially very simple geometries that can be made on mandrel, those tend to be, or historically have tended to be, made from thermoplastic resins, which are much, much tougher than a lot of the epoxy resin systems that are used.

You know, my favorite thermoplastic, actually bike industry story comes from a former GT engineer. And if you remember GT got in the late 90s, early 2000s, made this beautiful full suspension mountain bike. And I do not remember what it was called, but it was thermoplastic resin, carbon tubes. And then it had these aluminum lugs to make the hard points for the suspension and the head tube.

And you could see where the carbon went inside the aluminum, but then it was all smooth, kind of monocoque-looking on the outside. And so it was just this beautiful black and silver, and I'm sure we can look this thing up and find the name of it. But they were one of the first companies to get advanced thermoplastic resins in cycling, and were really trying to tout the toughness of this, because the toughness, which is where your impact protection comes from,

is so much higher in thermoplastics than it is in thermosets, right? So epoxies would be considered thermoset, and thermoplastic is a different thing. And the story goes they did a ride camp at Moab and they had an engineering intern.

who had planned with the marketing team this sort of gimmick where they drop the bike on the ground and he kind of puts one foot on each tire, right? So he's standing over, and he takes a baseball bat, and he whacks it down on the top tube.

and he's in front of all the media and he smashes the top tube and the baseball bat and the top tube both rebound with so much energy it flies backwards, hits him straight in the forehead, splits his forehead open, knocks him unconscious. There's blood everywhere; this is kind of like an epic

Elden (1:05:54)
Yeah.

Josh (1:05:55)
like legendary bike industry story, and you know, and you're just like, yeah the bat and the bike

Elden (1:05:59)
But the bat and the bike are fine.

Josh (1:06:02)
are totally fine

But yeah, so yeah, something like a thermoplastic resin and then also, you know, using slightly different materials. You think of the typical failure mode in a carbon...

epoxy, well, any carbon system, but a carbon epoxy system starts with some sort of like delamination between plies. And in the case of an impact, you're often like you're beginning to delaminate plies and then your innermost ply of that impact is seeing the highest strain and strain is like the stretching sort of. And so as you delaminate, lose the ability, you know, delaminate is like the layers becomes begin to separate from each other.

And so you begin to delaminate within the epoxy, then those interplies are starting to hit their strain limit, which in carbon is quite low, just a couple percent. And then as you lose the ability to transfer those loads elsewhere, the strain actually just goes up because now it can deflect more, and then you start to break, actually break the carbon. You know, one of the things you see in a lot of...

I don't know about bats as much, but I know hockey sticks is they use a lot of woven fabric. And because the woven fabric goes over under the toes of carbon, those over under weavings, we call it crimping. And those crimps give you a little bit of ability to handle those strain loads better because there's little bit of flexibility. It's not like a straight thing.

that you're trying to bend, it's a bent thing that, it's kind of like when they put a curve in a seat stay, right? That it kind of makes sense to you, like, that's gonna be a little bit more flexible than if it's straight. And that's kind of the similar thing that happens here. And so you can typically see more strain tolerance in things made from woven fabrics than are made from unidirectional fabrics. And then there's like 27 other things you can do to solve that. I would say the last of those,

and I would guarantee that it's probably in both of these is you use a lot of thin, what's called a scrim layer of fiberglass.

and fiberglass has much higher elongation than carbon. And if a scrim is like a really lightweight weave that is something akin to like, what is it called, like twill that they make like wedding dresses? You know, like the veil of a wedding dress. It's like that material. That's what a fiberglass scrim looks like. And you can put that both on the inside and on the outside of your carbon structures.

And then when it's wetted, because it's fiberglass, it's essentially clear. And so it disappears and you can see the carbon underneath. But what you've done is build yourself, when you flex a structure, your peak strain comes at your surfaces. So you think of like, an I-beam, like an I-beam in a building structure or a bridge, right? Like your peak compression is on the top surface, if your load's from the top and your peak, you know,

elongation is in the bottom surface and the stuff in the middle has much less strain. And so that's a thing that people commonly do when impact tolerance or high strain is an issue: you build in fiberglass, and if you're clever, you just do it in a way that you can hide it. In cycling we use fiberglass. Typically I would say pretty carefully because it's higher density than carbon and so and it doesn't add

much strength or stiffness and so it comes in as weight.

Elden (1:09:52)
Mm-hmm.

Josh (1:09:53)
So you're gaining, you're getting the toughness and the strain capacity but you're doing it at some cost of weight.

Hottie (1:10:02)
The bottom line for Peter in Minnesota: Peter, do not take your carbon bike frame and hit a softball, and do not shoot a hockey puck with your carbon bike frame. Bad. Ride the thing.

Elden (1:10:12)
Ha ha ha.

Josh (1:10:15)
And don't hit your carbon bike frame with a baseball bat or a softball bat. Regardless. Regardless.

Hottie (1:10:18)
There we go.

Elden (1:10:22)
It just does seem like a bad idea.

Hottie (1:10:23)
Yeah,

There's no way it depends on that stuff. Just don't.

Josh (1:10:24)
wear yeah

wear and wear a helmet i would say that should be the other lesson

Elden (1:10:29)
Yeah.

Josh (1:10:30)
here wear a helmet

Hottie (1:10:32)
Hey,

we want to hear all your questions and here's how to submit. You can text or call that Marginal Gains Hotline at 317-343-4506. You can also comment on this or any episode at MarginalGainsPodcast.cc. By the way, if you're on the Silkis site, like buying something, click the Marginal Gains Media tab. You'll find the show over there, too. and you can also find all the platforms for listening to the show at MarginalGainsPodcast.cc. Don't forget about that.

Josh (1:11:01)
Thanks again for watching, and we'll be back soon with more questions and answers on marginal gains.

Elden (1:11:13)
We'll talk about the Omata another time.

Hottie (1:11:15)
Okay.

Josh (1:11:16)
Yeah, that's good. Yeah, we'll give it a week. We've already sold out of them, so we gotta make the next round. They're so slow to make.

Elden (1:11:21)
Mm-hmm. That was one of my questions: how is it doing?

Josh (1:11:26)
really well. I mean, we have enough faces to make 2,000, 2,100 of them. We made 200 for the launch, and we are now sold through them. So, yeah, better than I thought. mean...

It's sort of, to answer probably your big question, like, you know, why did we do it? I just kind of wanted to see if, is this an interesting category for us to get into? We could get the technology. Well, we bought the trademark and the technology for nothing. And I could get the parts for essentially cost. so, you know, it won't be like a super profitable thing, but.

I kind of wanted one and a bunch of people I knew kind of wanted one and were like well let's try it and if we learn something that maybe maybe we could get in the digital device space but the more I learn about digital devices the more I'm like I think we probably want to avoid particularly

Elden (1:12:23)
Mm.

Josh (1:12:24)
it's it's fucking Europe I mean, Europe is just killing us in everything right now with compliance and just it's

Yeah, I mean, it's just, it's unreal. The compliance, the paperwork, the bullshit, Just the sheer anti-American... I mean, that's a little bit everywhere, but I mean, it's crazy town right now. So... Yeah, so good times. But no, they work. It's fun.

Elden (1:12:53)
Be a good conversation to have. I really do think so.

Josh (1:12:57)
Yeah, that would be... Pick it up in the next one.

Elden (1:12:59)
Alright, I'm gonna stop recording.