143. Why are the pros so fast, and how can we go faster? with Dr Xavier Disley

0:00So fun pub quiz fact, the processor in the Hammerhead Karoo bike computer is about a thousand times faster than the one that put man on the moon. And it also has 64 gigs of storage to store global maps and ride data, which is literally a million times more than the Apollo 11 guidance computer had. And yet it's smaller than a bar of soap and weighs just 118 grams, slightly less than the Apollo system, which I think was 29.5 kilos. To be fair, it took eight days to get to the moon and back, as it's about 380 ,000 kilometres, which is only slightly longer than most Audaxes, and the crew is good for up to 35 hours.

0:39But I still reckon Neil and Buzz's minds would have been blown by the crew's detailed but simple mapping. It's all free to download, it's available offline, and it includes base maps, heat maps, popular routes, topography, and even the surface you're riding on. the Karoo can flag up upcoming gravel sections as part of its turn-by-turn navigation. It also does loads more besides. I mean, I don't know if Apollo 11 ran Spotify or could connect to Bluetooth headphones. So check out our full review of the Hammerhead Karoo at cyclist.co.uk and see why we gave it our Cyclist Recommended Award. Then head over to hammerhead.io and use the code cyclist to get a free heart rate strap with every Karoo purchase.

1:21just be sure to add the strap to your cart then apply the code at checkout

1:30hello and welcome back to the cyclist magazine podcast i'm your host james spender and i don't know what i've done to offend everybody but i'm on my own again this week i've also got a bit of a cold boohoo me fetch those tiny violins i'll introduce you to our guest uh for this week's episode pretty soon. But I just wanted to do a shameless plug for the magazine, which I also, the cyclist magazine that is, the magazine cyclist, which I'm holding in my hand for anyone that's on the YouTubes and which I am holding in my hand and I'm describing holding my hand for anyone that's just listening. Our latest issue is due out probably a couple of days.

2:07Well, actually it might even be in the shops by the time you're listening to this episode. And It is a corker, if I do say so myself, because I personally wrote a feature on Mr. Bradley Wiggins. You'll probably have seen him in the press. His book has just come out. Loads of amazing stuff in there. A lot of it really tragic. Definitely, if I could reach for it, I don't have a long enough hand. I'd show you the copy of The Chain, that is Wiggins' book, which is published by HarperCollins. Yeah, it's an amazing read. Great Christmas present. But an even better Christmas present would be a subscription to Cyclist Magazine.

2:39And I tell you what, it's worth this one page called Pick a Mix. Again, I hold up a page that says Pick a Mix for those listening. It's worth this one page alone. And I'll read some of the jokes that Will Strixen, who's not here, inserts onto this page. It's five things that every cyclist would love. And Will somehow mixes in some outrageously poor jokes into little write-ups. So in this one, for example, there's some socks, a book, and some energy gels. Kind of boring, really. But listen to this. So, joke number one. Someone recently accused us of plagiarism. Their words, not ours. American smile, Europeans, skill-o-meter.

3:18Yeah, you have to think about that one for a while. Why was the archaeologist struggling? His life was in ruins. An old comb is hard to part with. And then finally, how did the chickens take over the farm? There was a coop. Very good. That was issue 170, still in shops. issue 171. No, I tell a lie. That's 168. Issue 169 will be coming out or is already out. And now I will move on. I'll stop making this advert for us and I'll move on to making it a lovely intro right up for our guest today, which is Xavier Disley. Alone, you know, his name alone indicates greatness, I think. Fantastic name. And he was also a doctor.

4:02So I should throw that in there. really sounds like someone out of the X-Men and he kind of is. He is like the X-Man head aerodynamicist. Now, Xavier is a sports scientist, aerodynamicist as mentioned, and a national master's track champion to boot. He's also the founder of AeroCoach, which is a coaching outfit, which is exclusively kind of made up of obsessives from around cycling, be they coaches, sports scientists, engineers, or aerodynamicists like Xavier. And they have one kind of major goal pursuit in mind, and that is basically just to go faster on a bike. So with that in mind, you kind of get the idea.

4:42It's tweaking rider position. It's changing things like skin suits. They make loads of equipment themselves, like bar extensions, tri bars, wheels, you name it, anything that can make a rider go faster, they've got a hand in kit-wise as well as, yeah, as I say, tweaking and testing people's positions in wind tunnels and on the track. And to that end, AeroCoach and Xavier have worked with basically everyone you could think of in terms of champions in cycling. So World Tour teams, they've had a hand in Veltas Spanier victories, Giro d 'Italia victories, Tour de France victories, our record, track records broken, Ironman, the list goes on and on.

5:28So Xavier is the guy I felt to talk to about aerodynamics. And the reason I wanted to do that is because I found myself once again thinking, hey, I know what aerodynamics is. I can explain that to a mate. And then I get halfway through and it's just this, I don't know what it is, it's inarticulate nonsense, the witterings of a mansplainer with some serious holes in his knowledge. So I thought I'd kick off asking Xavier, what is aerodynamics? Explain it to me like I'm five. And then from there, we try and kind of build a picture of what slows people down, what makes people faster and how even, yes, dear listener, you and me, how we can go faster on our bikes for free.

6:10You don't just have to buy stuff, you can get faster in the way that you position yourself on the bike. So we dig into that. And we also, because it's the Cyclist Magazine podcast, meander off in various other directions too. So Xavier was a really good sport on that regard. I've spoken to him before as well for the magazine. Did I mention the magazine? Also the website, cyclist.co.uk. Anyway, so I really appreciated him giving me the time again, because he's tried to get me to understand this previously and here I am asking him similar questions about a year on. So apologies to that, but I do hope listeners that you really dig it as much as I did and take some notes because yeah, it's a difficult subject and then just have them tattooed on the inside of your wrist so that you can, you know, read them out during the chain gang.

6:58Anyway, without further ado, welcome to the show, Dr. Xavier Disley.

7:07So I thought I'd get back in touch with you, Xavier, because we spoke a while ago. You helped me on some stuff around BodyRocket, which is an aero measuring device, which I think we'll come to that later. And I came away from that conversation thinking, like, I really understand aero. And then the other day, somebody asked me on a ride, what makes a bike fast? What a massive question. And I was like, you know, sort of muttered something about smoothing airflow and disrupted air behind a bike not being good. And they kind of just looked at me and went, why? And at that point, I think like a lot of cyclists suddenly realized my knowledge has come up massively short.

7:51So to kind of settle this, I wanted to ask you a few really basic questions about aerodynamics so that next time me or somebody else on a group ride, they can go, aha, right guys, this is how it works. This is gospel. So I guess a good place to start, very general question is what is aerodynamics in its sort of most basic terms? So if we talk about aerodynamics and we mentioned cycling in particular, it's explaining how one of the resistive forces, so in this case, air resistance, is affecting your speed on the bike. So there's lots of different resistive forces that are slowing you down. Well, everything is acting.

8:35We're not riding in a vacuum. And there are things that will make you slower no matter how hard you're pushing on the bike. and you've got stuff like gravity and rolling resistance and drive-to-inviction and all that kind of thing. But aerodynamics is the big one, really. And so that's air resistance. And it's you pushing through air molecules, which you can't see. And it would be a lot easier to understand if we were all trying to travel through custard and you'd feel the difference. But aerodynamics and cycling is a tricky concept because it's quite ephemeral that you can't see air resistance.

9:13You don't really know what's happening until you measure it correctly. So, yeah, so aerodynamics in cycling is that. Trying to understand that concept and how we can improve your aerodynamics to then speed you up for a given power output. And that's really the kind of goal. You're never really trying to slow yourself down. There are other instances in, let's say, other industries where, let's say an F1, where you're trying to induce drag force, downforce sorry so you can corner better in cycling it's really just about reducing your aerodynamic drag so you can go faster yes you don't want to have lifts and you don't want you know you make a weird front end see if front wheel starts lifting up you can't you have no traction whatever but that currently that's not happening so yeah aerodynamics and cycling is is you know the goal is to reduce your aero drag and then that'll speed you up and so if that's the goal how do you get there?

10:05What is happening for an aerodynamic shape which isn't happening for an un-aerodynamic shape? So there's two things to think about when you, let's say you're moving an object through the air and obviously a cyclist on a bike is a pretty complex object and you have two types of aero drag really that are majorly slowing you down. You've got pressure drag, So the pressure drag is the shape of the thing. And if you imagine the shape of an American football compared to a beach ball or something, they might have a similar kind of frontal area, but the shape of the American football is more aero, so it'll travel further.

10:46And then the friction drag is to do with the surface texture. So that's when you start thinking about things like clothing and stuff, where the shape of the object is the same, but what it's covered in affects the drag. So what you're saying, what we're talking about initially is pressure drag, and that's the shape of the thing. And so, yeah, so what makes something aero is how that shape is able to push through those air molecules more efficiently than a different shape. Now, the most efficient shape that you can design is going to depend on other circumstantial characteristics that are going on.

11:22So environmental variables like what speed you're going at, what angle of the wind is attacking you, that kind of thing. And so there isn't, for example, one shape or one bike or something that will be the fastest thing in all different types of cycling conditions. You have to tune the shapes and tune the designs depending on what motorcycling you're doing. So if you're designing a bike for track cycling and you've got sprinters traveling up to 80 kilometers an hour plus, that's going to be a very different bike than something you're going to want to use, let's say, for road cyclists in France, traveling on a flat stage, averaging around 45, 50 kilometers an hour.

12:05And that, again, is going to be much different from someone who's traveling 30 kilometers an hour, let's say, in a sportif or a more endurance-focused event, where shapes and designs and things will be vastly different. across their scales. So I didn't realize that. So if everything else was equal, shape X could be really very fast. And I'm thinking equal in terms of like imagining a bike going forward, maybe a wheel profile being a certain shape, and provided there's no wind attacking it from any other direction other than head on, or it's a perfectly still day, that wheel profile shape would be potentially different for reducing drag at 20 kilometers an hour versus 60 kilometers an hour exactly yeah okay so so what you you experience kind of yeah changes in flow attachments so flow attachment means as the airflow goes over let's say your objects in this case your wheel is fixed and the airflow is moving over it in real worlds you're kind of both of that happening at the same time, like you're moving through the air and the airflow is going over at me, it might have a headwind or something.

13:13The way that the air molecules pass over the, around the shape of the wheel or over the wheel rim or whatever, will change depending on the speed and the characteristics of those air particles in terms of their movements will induce areas of drag, so areas of different pressure and low pressure off the back of the wheel where if you take the example of an eddy in a stream you look at a stream flow of water you put a pop a pebble in it and you can see off the back of the pebble there's like sort of little swirly bits around the back of it as the water's trying to move around that's exactly what's happening really with airflow and that little those kind of eddy areas are in airflow terms areas of low pressure and they create trap and suck the wheel backwards, which is a bad thing.

14:01So you want to reduce those as much as possible. In very, very, very high speed situations, those eddies will basically be smaller than they will be in low speed, where there's more opportunity for these little air molecules to move around a bit, whereas very high speeds that can just go straight past a lot of the time. That's a very simplified way of looking at it, but certainly from a component perspective, it's kind of a bit like that. So you would design a wheel differently if you're designing a wheel for, let's say, even mountain biking or endurance driving 20-30 kilometers an hour than you would do 80+.

14:38And we do that. So when we're designing wheels and we've got track wheels that design for sprinters for those kind of speeds, and when you're simulating this stuff in the computer, you can see these eddies and you can see how the airflow moves over the surface of a wheel at different wind angles and when your wheel's off to the down tube and stuff like that. And so when we're designing stuff for slower speeds, we do time trial wheels that are more like 45, 50 km an hour, you can see exactly the point at which the airflow changes characteristics as it moves over the surface of the wheel, and therefore you tune the shape of the wheel to reduce these low pressure areas.

15:19so does that mean in a way the fastest sort of shape has balanced pressures at the front and at the back so having low pressure at the back if i understand you is like kind of having creating sort of vacuum which is effectively almost pulling the object back as it tries to move forward so that's a bad thing we don't want that conversely you're making higher pressure at the front because you're kind of pushing all the air molecules into each other there's more stuff in front of the object as you're going faster getting higher pressure there not really like with high pressure you'll see a high pressure zone when the air's got nowhere to go so let's take the example of a helmet so if you're moving through the air with a helmet there's a big high pressure zone in the very front of the helmet where the air kind of hits that relatively flat space and then has to kind of go somewhere else but it's creating this you know if you've got your finger and you start like pushed the front of someone's helmet that's kind of what's happening and so you see that companies will try and reduce this area of high pressure by putting the hole in the helmet there so the airflow can now just go straight through well ish you know straight through but they'll put some channels in or whatever so the airflow can go through the helmet and it reduces that that zone of high pressure so you don't you don't really want high pressure and you don't really want low pressure you kind of want the airflow to not realize that your object's there yeah if that makes sense you want the object to be as almost invisible as possible so you want to kind of like even even things out of it you can't obviously get rid of things completely but when you uh yeah minimize areas of low pressure and you try to at least manipulate what the airflow is doing in areas of high pressure, that's when you get a fast component.

17:07Okay. And so if we sort of took that and put it into the model of a peloton or riders drafting riders, as much as an area of low pressure behind a kind of lead object is sucking that object back, the object behind that object is enjoying the low pressure because there's sort of less air to have to penetrate because it's being sucked away by other stuff. Is that kind of right? Yes. And what you also find is that if you fill that gap of low pressure that's occurring behind an object, then the object itself will speed up. So if you put a rider behind a rider, the lead rider will go faster. It's not by law, but the lead rider speeds up.

17:54So if you're doing a team pursuit or something like that, then even if you have two riders, the lead rider, if they just have someone sat on their wheel they will be going quicker because of it um which is quite good to know if you're in a breakaway or something always you see even if someone's sitting on and you want to stay away always keep them on your wheel it's only a few percent but like it does it does have it interesting yeah i like that that's you know so next time someone jumps on jumps on my wheel on a ride out just let them sit there they're actually making me faster yeah i say that like that happens all time it doesn't eventually of course oh yeah obviously obviously but um we're looking thinking you know i was doing a bit of research around this for the this episode and i went back to a piece that i'd written a good couple years ago maybe 2018 or something and it was based on a paper by a dutch guy dutch professor guy i think called bert blocken which is wonderfully yeah sort of dutch name and a great name blocken for anything to do with drafting and he'd made this kind of terracotta, 3D printed terracotta army of little cyclists.

18:56So I had like 121 of them, and he'd stuck them in a wind tunnel in a kind of perfect peloton formation. So you've got one rider, then two, then three, then four in this kind of arrow sort of shape. And he deduced from this, from modeling this and analyzing the wind tunnel stuff, that like you said, the guy at the front can get something like 84 to needs to put in 84 to 96 percent of the effort he would have to put in or she would have to put in on their own just by being at the front with having those two people behind but sort of center about two-thirds back riders could be experiencing you know having to put in as little as five percent so to kind of cash that out you could end up having a rider who so he had a fit goodness knows where you know you can tell me about this later why we choose certain numbers for our area credentials but there's 54 kilometer an hour peloton which i guess is an average moving speed person you know center two thirds back could be pedaling as if they're having to pedal on their own at 12 to 15 kilometers an hour which sounds mad is that kind of is there veracity to that obviously this is real um this is ideal conditions so you don't have crosswinds and you've got everyone perfectly in formation.

20:14Yeah, I mean, if you've ever done a road race or you've ridden in, let's say, a sportique with like a ton of people, it is crazy how you can just be coasting and catching up to the people ahead of you. And yet you can see five up the line that someone's blitzing themselves to bits on the front of the group trying to stay ahead. And going back to the thing about having people sat behind you, speeding you up, This is why regulations were brought in to stop team cars from getting too close to riders. Because as you, let's say you have a four transit van or something, they're creating this big kind of bow wave ahead of them.

20:50And if you get in that bow wave as a rider or whatever, then that is speeding you up because it's kind of disrupting the airflow a little bit, making it easier for you to slip through it. And in a similar, smaller kind of effect, if you have a big peloton behind you, so like similar things happening. But yeah, this is why bike races are interesting. Bike races are won not by the person who's got the highest FTP, who just is not a walk bike competition. It's by people who can conserve energy. And I think that's what makes it fun. The taxis of bike racing are very unlike almost any other sport, to be honest, because of this added aerodynamic drag impact.

21:34even though we can measure it more accurately now, this has been a thing for year one of bike races. Everyone knows that you sit on someone's wheel and it's easier to pedal. Yes, we understand the percentages now and we understand how much your power output is affected and how many kilojoules you have, less you'll have to do and how many gels you don't have to burn to then stay four hours later and then going up a hill, all of that stuff. But back in the day, people were still making use of aerodynamics to improve their racing palmares um and i love that about it uh because it becomes that's very it was a it's a very innate thing you know for someone who doesn't understand cycling who just watches sort of france and they're like oh it's a big bunch of riders it's a bit weird but as soon as you've ridden a bike behind someone it's just like eye opening for the first time like a decent speed you know yeah um that you know 25k or something like that where you can feel the difference you know like my goodness you know so uh so yeah sorry gone off on a bit of a tangent there but i think that it's worth making the point that um that aerodynamics has always been a thing and people have always known it's been a thing it's just that in recent years and not relatively recently you know for the last 20 plus years people have been even more than that people have been doing wind tunnel work kind of on mass people have you people have been able to measure these things and so you can really see right in your face the impact of it when everyone's got a power meter and you can be like i'm doing as you say you know i'm doing 200 watts less than the guy who's killing himself from the front this is great yeah yeah i mean a bit of a tangent as well but it always amuses me and it's also kind of tragic that i think as there are records as far back as you know the first tours de france the first couple years from 1903 onwards where riders even knew this then because they would have someone in a motor car and they'd cycle behind them.

23:27So they knew, you know, there's all kinds of cheating like that going on. They kind of knew about this. And then in 1989, you have still the most famous Tour de France ever with Fignon losing to Le Monde in a time trial. And you're like, dude, this is like 86 years later. Have you learned nothing? Look at this guy, this American bloke on his low pro bike and his slick as possible kind of helmet. And then you're there with your little specs and your ponytail. And I don't know if it genuinely is true that that ponytail cost him those eight seconds. But sometimes I look at riders, both historically like that, and also today, I think, a couple of years ago, Roglic did a time trial and his helmet's just like all over.

24:10How are people getting it so wrong still? Do you sometimes look at TV in despair and go, guys look you've got millions in your budget and this is how you're choosing to set yourself up yeah i think that it's it is tricky so to go back to example so finion had a front disc on which was exciting uh and the mom didn't so that would have helped a bit and that was definitely like a nod to eros malics i think that yes yes it does get frustrating when you can see someone i mean we've had so many examples of like teams we've worked with and um individual riders and things and they're doing stuff and you're just like what are you doing like we told you not to do this um and we had a big we had a high profile rider that won a grand tour that we worked with like a couple years ago and like stage one tt we've been in the wind tunnel within recent like you know three weeks before or something and like stage one tt and they were doing something and i i text the sport director i was just like please tell me i didn't just see that and he was like yeah yeah yeah we we know we know but you can't be told you know and then the thing is a lot of these riders that they're on multi-million euro contracts right and then it's quite difficult to manage telling them you're not doing this like there's two there's two situations out there they're on the big whack salary so they can't be told what to do or they're on the big whack salary and therefore you definitely can tell them yes because they're you know but it's tricky anyway the rider was fine he won the race and it was it was all it was what was the thing what were they doing that they shouldn't have been doing i uh it was it was just something they did in the tt in terms of like where they were putting their radio and uh it wasn't anything it was radio i think it was a bit of ice or something anyway we'd had a discussion about it before and it was like we all knew what they were doing was wrong and it just they just did anyway because whatever and yeah can be quite frustrating.

26:03I mean, from a personal point of view, I do road races and stuff. I'm a para cyclist and I did some World Cups this year after May. I'm roughly up to the start line and I have got add to basket aero kit. I know what my CBA is on the bike. When I'm really hunkered down, it's nearly as good as a TT bike. There are riders there with flappy jerseys and things like that. and I'm not going to shout from the rooftops too much about it. But if you are off the front or if you're sat in a bunch doing nothing and the person next to you is swogging their guts out side by side in a group or something, you'd hope that they would at least take it.

26:45But for people, again, it's tricky. It's my job to know this stuff. And it's not a professional cyclist's job to have done a ton of wind tunnel testing or to understand the role and resistance of a particular type of tyre and things, it's too much, right? It's too much for just like a cyclist to, if their job is just to be a cyclist, you need to have support to be able to understand all this kind of stuff. And so that's fine. For a professional rider, there should be attributed to that support and things. When you move further down the scale and you get to amateur riders, how on earth would they know what to do when you've got companies saying this thing's the quickest thing and this thing's the quickest thing and you should only ride this or don't ride that.

27:27And you've got some Instagram video where someone's made up some rubbish. It just doesn't make sense. And I find it very tricky for the consumer to understand what's actually going to speed them up and what isn't. And with the amount of misinformation, not necessarily coming from a bad place, but if people are, let's say, doing testing or getting that test protocol wrong or something and then telling everyone, oh, we found that you must do this and you'll go super quick. And people take you at face value because why wouldn't you? It just becomes this kind of muddied water scenario where riders obviously do want to go fast.

28:08Most people do, especially if you're racing. And they might be making mistakes just because, like inadvertently making mistakes because the advice they've got isn't correct. Yes, you do then have riders who absolutely don't care and who just want to see the biggest number on their power meter. and just hope that I'll do it, and I don't like aero, and you should just be pedaling hard instead. It's just like, well, that's very commendable, but the goal is to win races in that scenario. So just try and win the race. Don't just tell everyone how big your normalized power was afterwards. That's not the idea.

28:42And that's the thing, right? And again, correct me if I'm wrong, but the basic rule of thumb that always gets bandied around is that the resistive forces you're trying to overcome in order to move you and your bike forwards are about 20 % rolling resistance and 80 % air resistance over around 20 kilometers an hour. And of that air resistance, you are about 80 % of the air resistance. Now, you're looking at me thinking, those numbers are wrong, James. Do correct me, but... The rolling resistance is a bit lower. It depends on what tires you're using and things, but tires these days are pretty good.

29:19So 20 % rolling resistance is a decent chunk, but you can probably see lower than that when you the faster you go the more is the resistance obviously but yeah the vast majority is that and then the vast majority is exactly as you say is the rider and the rider yeah the shape of the rider the surface area of the rider frontal area of the rider and everything is just so much more than the bike yeah because i was thinking with um pagacha this year he was riding almost i think exclusively colnago's aero bike so the y1 rs which is if anyone hasn't seen it it looks like the sort of bike that you drew in the back of a textbook when you're a kid to try and draw a fast bike so it looks a bit crazy it also looks like a bike that maybe time forgot but these designs have resurfaced i'd say more recently i moving away from that classic specialized tarmac double diamond drop seat stays pretty normal looking bike and going to something with scalloped seat tubes and more stranger angles all within the uci limits and a handlebar that kind of has sort of two stems that come out in a V.

30:24So this is a bike that ostensibly looks very different, clearly is a heavier frame. Obviously, I'm sure you can build it to a 6.8 kilos like everything else, but it's a heavier frame because it's just got more to it. And it's being ridden by the guy winning the Tour de France, who is a climber by trade, and his adversary, Vinigard, is also on an aero bike, Cervelo S5. Similar sorts of thing, looks like a kind of crazy bat bike. How times have changed, right? Because once upon a time, Pogaccia would be on like the lightest Colnago, Vinigard would be on the lightest Cervelo and R5, and they'd still be duelling for the podium and Pogaccia would probably still be winning.

31:05Are those bikes actually really genuinely useful to them, especially when they get into the high mountains? because they are presumably more aero? Or is the reality that it's just a marketing exercise and it's just another thing to confuse the consumer and make you think, hey, hang on, I don't have the fastest bike anymore because my bike looks so different to these guys. So that's a good question. I think obviously behind that, there's companies want to sell bikes. Yeah. And I don't think that there is, for the vast majority of companies, a nefarious, evil, like, you know, whoever the evil guy was in Danger Mouse, evil overlord.

31:46Yeah, yeah, yeah. Saying, you know, let's try and confuse the consumer. The thing is that certainly for companies that are designing bikes for Tour de France riders to win the Tour de France, that's a very different thing than a consumer who wants a Sunday club run bike. Yeah. So I suggest that the V4 RS, which is the lighter one that Colmargo made, as an example, is probably the better bite for 90 % of Calmarco's customers because you're not going to be needing to ride this thing a 50k an hour. Yes, it will be a bit slower and less aero, but the geometry might be more helpful. You might be able to change your handlebar setup to get you in a better aero position or comfortable position or whatever compared with the Y1 RS where the handlebars are very integrated and very difficult to change because all the cables go inside and stuff like that.

32:37So from a practical perspective, the lighter bike, although it's less aero, might actually be the better bike for you. But going back to one of the questions you asked, which was, is it actually making a difference? Yes, it will be. And even if it's like slightly heavier, and again, because we have these UCI weight limits of 6.8 kilos, you're not really denialized as much as if it was five kilos and you got like another kilo off the bike at crucial moments at the end of the race. but it's those crucial moments only happen at specific points you might have been riding for three or four hours before then and you on the aero bike could have been saving x number of calories and your workload will be so much lower on the aero bike on the flat bits and on the descent and all this kind of thing such that when you get to the final climb you haven't extended as much energy and therefore you go up the climb with fresher legs and that's definitely something to bear in mind um because a tour de france race is a big set of energy expenditure calculations really you know you can't you can't survive by maximizing your power up for every day it's all about conserving energy and conserving pace so that you can only do that at specific points over the course of the three weeks so in those situations an aerobike is actually pretty good because unless you've got a summit finish you're going to be going up a mountain yes you're going to be coming down it and you're going to be faster coming down it on the aero bike than you would do otherwise and then when you're on the flat you're going faster as well so yes it might just be on the summit finish where there's basically a toss-up between the two bikes and they're kind of similar because there's only 800 grams between them or something but everything leading up to that you've been going quick yeah um so yeah so i think and and we know that aero bikes are more aero than non-aero bikes right that's definitely a thing yeah yeah um so uh and And the differences can be quite big.

34:29I mean, Colnago, I think they quote, and they did a white paper, which is basically a big detailed information sheet on how they developed the frame. And they gave some numbers about it. And it's pretty good, actually. It's heavy reading. But what I mean is they really explain the process behind which they developed this bike. And I like the fact that companies these days are doing a bit more of that and attracted that with the Evadone, explaining about the process behind making this thing rather than just, oh, we just made some aero shapes and kind of blended them together to make an aero bike.

35:05It was like, no, no, we put sensors all over this thing. We took it to the wind tunnel. We did this work in CFD. In the computer, we optimized the frontal area of this thing. So Colnago say in their paper that it's more aero than their other bike. I think it was, off the top of my head, there's like 20, 25 watts or something at 50k an hour, which is a decent... Wow, it's just massive. Yeah, it's a decent wedge. And, you know, if you take that kind of conspiracy route, like they would never say that about their other bike. You know, they wouldn't say that the new bike is so much quicker than the other bike because they still want to sell the other bike.

35:42Yeah. But both of those things have a place depending on whether you're using the bike for, you know, racing or going fast on your own, even if you want to do that, or if you're using the bike for Sunday club run kind of thing. So I think there's a place. There are obviously companies that are just trying to do a do-it-all bike. The new Trek Madone is kind of a bit like that. Specialized SLA is perfect. They wanted to keep – and in the current climate, trying to keep down your SKUs, your stock-kept units, different models of bike. Just have fewer bikes. Yeah, it's just way easier to manage it.

36:16So having a bike that kind of does it all. but i i'm i'm in no doubt that specialized if they wanted to could make a bike that was more aerodynamic than the sl8 like definitely they could do that they wanted but that's not really the point of the bike the point of the bike for them is just we just need one thing that will be light enough and nice enough and easy to handle and and whatever and people seem to like the bike so that's fine and it wins races and stuff yeah um in a wind tunnel shootout like they could make an updated Venge, which is their previous aero bike, and convinced they could do that and smash it out of the water.

36:50Maybe they will do. But the last five years' worth of bike industry is probably not the environment to do that just yet. Yeah, totally get that. And I would say, I don't know if there's William Hill giving odds on it, but the Venge must be coming back. I can't imagine they'll shelve it forever. It'll just be a matter of time before they go, by the way, we've just made this bike. We're going to call it the Venge, and it is significantly faster than the SLA, which when that bite came along, they said, we're only doing this bite now because it's so much quicker than the Venge. There's no point in having the Venge.

37:21And you're like, and that's where as a journalist, I start becoming a bit suspicious. Like you say, it's not, I can't remember the guy's name. I'm going to look him up afterwards, but he's a toad, isn't he? In Danger Mouse, I think. Is he a toad or a frog? He's a toad, I think, yeah. So there's not this like nefarious brain trying to manipulate consumers' passions into money. but at the same time i'm constantly bamboo you know overwhelmed by white paper this justification that this is four watts faster at 45 kilometers an hour which you're like okay that sounds great but what does that actually mean four what's faster at four okay and i do wonder how genuine lots of these kind of claims are because there's no way of interrogating them do you really believe when you see these things come out yeah conago's done its due diligence this is all real stuff or do you are you left sometimes feeling like yeah they've chosen a perspective that allows them to say things and there's to my mind there seems to be fewer and fewer we tested every single top end wheel and here's a list of them named with some drag results like you got maybe five years ago where i feel like that's missing it's just like oh no this is our fastest wheel and it's our fastest wheel.

38:42It's not the fastest wheel. So it's a great question and I do get asked this a lot and we get this asked this a lot. And do you know what? It's quite impressive that you've mentioned the wheel thing because we're just about to bring out a new wheel, two new wheels actually for TT. And it's exactly as you say, I'm constantly frustrated by companies that either test their thing against one competitor or something and it's just like what's the point right or they test it against their previous stuff because i don't know why you'd only do that like i've got the balls to actually benchmark it or they have benchmarked it and it's not any good yeah um so we just spent tens and tens of thousands of pounds on competitive stuff during the process of developing these new uh these new wheels that we're about to release and we we're not releasing them until they were better than everything else I don't know how else you do that, you go through that process.

39:39So either people are not bothering or they are bothering and they're not giving you the results because their stuff isn't better. You also run into issues about protocols. So I think you alluded to that a little bit about someone's carry-picking things. So if you're not using the correct protocol when you're doing testing, then you will end up with something that you think is really good but actually isn't in a scenario which is a better protocol, a more realistic real-world protocol, for example. So this is when you run into situations where a company will tell you that, and we saw this with clothing, to be honest, for a little bit, maybe like three, four years ago, where everyone was coming out with a new sock or a skin seat or something, and it was like, oh, that's 20 watts faster than the next one.

40:22And it's like, it isn't. But the way that you're testing it and the way that you're taking that particular data point and saying that that's the thing you're going to hang your hat on, fine, that says 20 watts different, but in the real world it isn't. And so you end up with this kind of situation where you have to have your protocol and the way you're testing things. That's got to be set from day one. You've got to know exactly what you're doing because all your products are going to be based on those decisions. And if you make anything, you make a single mistake up here, then you're stuck. And it's not because you're releasing something that is no good.

40:58like everyone's trying to work hard you know people are paid at these companies to to try and make a thing that's quick but if it's all based on the protocol you set up here that's wrong then you may make something that is quick in those circumstances that are incorrect therefore isn't quick um and there was a big wheel company that some years ago now but that you could tell that they had changed their test methods or internal protocol or something for a particular generation of their wheels because they were all terrible, like really bad. You had generation one, let's say it was fine. Generation two was just atrocious.

41:34Generation three was fine again. And it's not because everyone decided to hamstring themselves and make something that was really bad. It's because they obviously just got all their test breaks put them wrong. And then now they've moved on to, you know, they changed that, figured it out, that stuff was an issue. and now they sort it out. And you also mentioned something about people buying things based on emotion. And I think that that's a really important aspect of the cycling industry. Because as a consumer, you can't go and test everything. So a lot of your purchasing will be based on emotion.

42:09And cycling itself is difficult, isn't it? You're exerting yourself. If you're doing racing, it's often very painful. and so you go through a range of emotions when you're writing and when you make a purchase you want to feel happy or you want to have a positive emotional experience when you make a cycling purchase i know that sounds really silly but that is true you don't want to be buying something thinking i hate this i don't want to buy this this is going to make me sad if i buy it yeah so bicycle companies and component companies and things will want to make you feel happy about your purchase sometimes people will do that by making an aspirational product where it looks cool or you've got your favorite rider uses it and therefore you want it for that reason and then some people will make it and i think we fall into the second category where we just focus on the performance of the product i don't really care what it looks like um and i'm not really bothered who's riding it necessarily but the emotional part of it is that you can feel very happy because you trust that it's the fastest thing and it will speed you up and so yes this transparency aspect of the of the industry when you're looking at buying a component or whatever and having as much information available to you as possible presented to you in a manner that is obviously not cherry-picked or rubbish i think is dead important and so yeah um yeah fine i'm trying to beat the error coach drum here but that is what we try and do like we're not trying to be flashy or anything all of our money is spent on r &d like we don't sponsor a zillion riders or something like that to try and get that side of things we're just trying to make sort of fast kit and so yeah all the wheels in our new the new range we're going to release we're going to have graphs we're going to have every single wheel the name of it the model of it all written on the graph testing loads of different tires as well all that's going to be published too and then people can make their own decisions you know but it's just when you get a graph where it's just like oh we said i mean against the best competitor in inverted commas, wouldn't name who it was.

44:12It's just like, why not? Although I think in that instance, they did something weird, like they averaged everyone. They did a load of competitors and they averaged them. Well, I think they might have done better. They took the best result out of each of them and then ranked themselves against that. And it's just like, I only found that out because someone had told me that. It's just like, that sounds amazing. Why not give the consumer that information? and I don't know why people have this allergy to naming competitors on marketing stuff because the data will have been collected in good faith you'd hope you'll have evidence you've actually collected the data as well people have done this in the past and no one's freaked out about it like you know the companies have done this for years giant trek sabelo uh i'm pretty sure specialized have done it and then wheel companies like head and zip and that all putting graphs up with names of competitors and their wheels or their bikes or whatever.

45:09And I don't understand why people aren't doing it anymore because there was a period of time, maybe 15 years ago, when everyone was doing this and I felt as though that was great and maybe they're worried about giving away their protocols. I think it was Gerard Vrooman actually said he was happy that Cervelo finished second in everyone's tests when they're testing their stuff because they were seen as the benchmark. yeah and it's like yeah that only happens when people are naming you as the benchmark but yeah that's not really going to make someone buy your bike i don't know yeah it's a funny question i've gone off but maybe maybe that is the uh maybe that is actually a big uh nefarious kind of syndicate of bike manufacturers and they all meet underground in a kind of like on an island in the middle of some lava and they're all saying at the moment you know what we've had a horrible five years let's not name and shame each other let's just let everyone have a slice of the pie for a while until we stabilize and then we can go back to saying that zip wheels are faster than envy wheels yeah whatever it is but on the on you'll be sorry go on i was just going to say you'll be i think you'll be interested to know just how friendly people are in that kind of space so there's like a group of manufacturers to join together to as part of wfsgi which is the world federation sports and goods industry and we're part of that and you know we're often in meetings A lot of this stuff is to do with understanding UCI regulations and having a voice to speak if things are changing or just in general with safety stuff.

46:39And all the major manufacturers are on there, including little old us. And everyone's pretty cool with each other, to be honest. There's people who are quite open about some of the stuff that they're making. and whenever we're having discussions with, you know, let's say competitors or competitors, not us necessarily, but you can see that everyone's fine with it. You know, it's not like an evil industry, if that makes sense. Like everyone's quite friendly behind the scenes. And I think in general, like in front of the scenes, everyone's pretty cool with each other as well. No one's like, you know, for want of a better term, shit talking each other constantly.

47:20There's very little of that. which makes it quite a nice environment to work in from that perspective actually sorry you're saying going back to words no no but i'm just on that point i think is always strikes me as quite interesting about cycling because they talk about well you know we talk about it maybe the rest of the world doesn't as you know it's like the f1 of kind of human powered sports because it has this technological side to it and i remember going to red bull's got like a facility or used to have a facility in milton keynes it's obviously got loads all over the world but for its f1 team and they got sick of having to look for people in the bushes taking pictures of their cars and so then they put apparently they put you know big blankets over these things to roll them across you know from kind of um hanger to hanger and then that was difficult and so then they just built a tunnel underneath two buildings so that they could just move their stuff around without people's anything yeah that's probably probably a bit of folklore in there but so different to cycling where more and more it seems to me it's circling back to you know he that idea of they could have won that on any bike once upon a time bikes were very you know quite vastly different and probably there's much more tech in a cheap bike an expensive bike than a cheap bike but just looking recently one of our bike reviews coming out this issue is for a cube lightning air which is a lighter version of their aero bike and that's raced by Binyam Gourmet and other pros on Wonti.

48:49And that's an eight grand bike in top spec. Cheapest pro peloton bike, whereas I think Pogaccia's Colnago is the most expensive around 16 or 17 or something. And you kind of think, actually, there's not that much difference in bikes technology these days. It has kind of, or I don't know or maybe i'm wrong do you do you look at bikes and go actually that is a much better bike it's definitely got more than that cheaper bike i think that the world tour level because everyone now understands the importance of various things about bikes whether it's in terms of aerodynamics but mostly aerodynamics there isn't really a standout crap option yeah yeah um whereas there might have been a few years ago you know where you're just like oh that's not really the one you need to be using.

49:38Maybe there's, I don't know, yeah, there's a couple of bikes that aren't like super aero, but everything's kind of pretty well made. I think it more comes down to, let's not forget, you know, the rider is the bar source of the drag. So if we're just talking about aerodynamics like performance from that perspective, you might have riders who are using handlebars that are the wrong width for them or something like that just because everything's so integrated, it's a pain to change them or they don't have the particular model of handlebar for that frame or that combination of integrated stem and bar to get the rider in the exact position that they want, which still happens at World Tour level.

50:14It's not like something that's just, you know, that us consumers have to wrestle with when you're trying to buy an integrated bike. So, yeah, I think the bikes are more similar now than, let's say, some years ago when the best bikes were really good and the worst bikes were, like, really not great. the gap has kind of narrowed slightly i think you're right so fun pub quiz fact the processor in the hammerhead karoo bike computer is about a thousand times faster than the one that put man on the moon and it also has 64 gigs of storage to store global maps and ride data which is literally a million times more than the apollo 11 guidance computer had and yet it's smaller than the bar of soap and weighs just 118 grams slightly less than the Apollo system which I think was 29.5 kilos.

51:05To be fair it took eight days to get to the moon and back as it's about 380 ,000 kilometers which is only slightly longer than most audaxes and the crew is good for up to 35 hours but I still reckon Neil and Buzz's minds would have been blown by the crew's detailed but simple mapping. It's all free to download, it's available offline and includes base maps, heat maps, popular routes, topography, and even the surface you're riding on. The Karoo can flag up upcoming gravel sections as part of its turn-by-turn navigation. It also does loads more besides. I mean, I don't know if Apollo 11 ran Spotify or could connect to Bluetooth headphones.

51:43So check out our full review of the Hammerhead Karoo at cyclist.co.uk and see why we gave it our Cyclist Recommended Award. Then head over to hammerhead.io and use the code cyclist to get a free heart rate strap with every Karoo purchase. Just be sure to add the strap to your cart, then apply the code at checkout.

52:08Do you find or how often do you find a rider coming from a pro team, world tour team and saying, guys, this is what I've been given, but I think it could be faster. And I've always got in mind with a question like this someone like Alex Dowsett who put a lot of personal time and resources into developing things to help him go faster which weren't team issue or another good example I think is Adam Hansen who realized that having a 36 centimeter bar would be really advantageous but the team was like we don't do that and so he that's a that's that's that's a women's bar and so he had to just go out and buy one himself I mean that's a great example because he's one of the people that has been trying to champion the new UCI regulations to, I don't really want to say the phrase, but screw everyone over.

52:58So, yes, I think he's, yeah, because he's president of the CPA and he has been attempting to very badly, in my opinion, justify the UCI regulations on handlebar width. Whether they're right or wrong, he doesn't understand them and has been a very poor advocate of that. That's the end of that. sentence but yes sorry your point was nothing to do with adam hansen really it was more about riders uh looking to make a privilege yes so we yeah we see we see and certainly when you have riders who swap teams like we've had that with riders where they wanted to understand the limitations of the new equipment that they've got on a new team uh and and what they have in their old team um we're in constant contact with you know riders from the world tour who are asking is questions about the stuff that they've got available to them within the team and what choices they should make.

53:54Some of this kind of stuff is done internally anyway, so you'll have experts in the team who can say, look, you should be using this particular component for this particular scenario, and you should use this for another one. But sometimes having a little outside sanity check is good, which is why people will contact us. But also because you're paid to be a pro rider, and you're paid to be a pro rider on a particular team, and you're paid to use the kit that you're being told to use and your salary is coming from those companies. And so I very much understand the potential frustration of someone who either knows because they tested it or thinks that the kit that they're using isn't the right thing for them, but your salary is coming from these companies.

54:37So you're being put in that position of racing your bike purely for, you know, because you've got to do that and you've got to use that. You've got to use that kit. So sometimes it's better not to know. And I think that a lot of riders take that position because what's the point of knowing is you can't do anything about it. It's just going to stress you out. And unless you've got a component that's unsafe, that you can prove that a tire has no grip. We have this with a team. There were tires that were just, riders were really unhappy with them and they put their foot down so we're just not riding these particular model of time.

55:12They didn't have any grip and the wrong resistance was terrible as well. and the team were like okay fine we'll take that we'll let you do whatever but if you're using i don't know let's say you've got a time trial wheel or something like that and you know it's not as quick as an alternative option but you can't do anything about it just one deal with it two try not to find out in the first place like there's no point testing equipment that you can't use So, yeah, it's a tricky one. And then you run into situations where some riders will have more sway over the stuff that they can use. And they can use deep-batch things and particular custom components because they're allowed to.

55:54And then you'll have the kind of more domesticky, lower-down riders who absolutely have no choice. We had a WorldScore rider buy some stuff off our website just randomly. I think it was like a couple of months ago. and then we got a message from like two days later they're like oh and like a day later i think it's like hello sorry can i actually cancel this order before i've gone out can i cancel this order because i've just spoken to my team and they said we're not allowed to use your use your stuff because it fits with a sponsor and i'm just like i was like we'll take the logos off for you it's fine like we can stick whatever logos you want on it i don't care and he was like i'm really sorry i'm like that's whatever it's fine just yeah cancel refund um so so it does happen and it's it's quite nice that riders are looking for improvements themselves like i quite i quite enjoy if a rider has a custom component or something it's always quite fun to notice that isn't it um and to see that they've done a bit of homework but i think that the scenario where a rider let's say this imaginary rider is just like freaking out over every single piece of equipment that they're being forced to ride overall their performance is just going to be worse right because you're just getting stressed the whole time and you're constantly battling against your team who are then getting upset with you because their sponsors at them because the rider's not using this and stuff like that it just makes life a lot difficult so if you're a professional rider on a team with restrictions just understand that you're only there because people are paying your salary and your restrictions are basically part of that now the ideal situation is that you're a professional rider on a team where you can't fault the kit that you've got yeah and you're convinced that everything you're riding is the fastest kit that's like happy days double thumbs up kind of situation but uh not everyone has that and you know that's quite a rare rare occurrence yeah i remember being um a kind of q a with cavendish uh years ago and somebody stuck their hand up and said mark what's the best bike you've ever ridden and he just said the one i'm riding now and it always is the one i'm riding now so yeah but for the you know for the rest of us people who could come to aero coach and say zavier make me faster but i'm on a budget so talk me through my options.

58:04Whereas, you know, this is the perennial kind of club ride question, what's the most bang for your buck? And I appreciate there's not a kind of concrete list, but broadly speaking for most situations for your average sort of rider, where are you best off spending your money? Skinsuit, helmet, wheels? I mean, wheels are really expensive. A helmet's much, much cheaper, but then actually a wheel's way more useful to you speed-wise. Yoga lessons so that you can hold a better position on the bike. Right. Because that's it. I did our local chain gang last night. And one of the guys who works for us was on it.

58:44And his bike is like a standard bike, rim brake bike, round tubes and things. But the position he holds on it is immense. So all the people on aero bikes are not going as quick as him when he gets to the front because he can contort himself into a nice aero position. So that's the kind of cheeky answer is yoga lessons to get yourself as there as possible. Do some stretching, that's free. But it is important. And so I would heartily recommend it. The next bang for the buck really is tight-fitting clothing, just making sure that your clothes are flatly. Again, that could be free if it's just a case of selecting a different jersey from the wardrobe.

59:23And you don't have to spend like a million pounds on, you know, the latest Aerotech jersey or road suit or socks or whatever, like if it doesn't fit you properly, it's going to be slowing down a lot. So that's like absolutely dead important. And then from a, if we ignore the rider and we're just thinking about, we're looking at a picture of your bike and it's just like, right, where am I spending your money? It's tires, like tires, just straight away. Sort yourself out of tires. Even if it's a case of you've got a beautiful tube, so a black thick beautiful tube inside the tires, to put a latex tube in or a TPU tube or something like that, it'll make such a difference.

1:00:00Usually more than a set of wheels, depending on what your starting point is. And if you've already got a deep section set of wheels and you haven't got the right tires on, you could be really slowing yourself down. I mean, I ride rounds. I do road races on time trial tires, for example, and that makes a huge difference. And there's definitely big savings to be made there. And we have free data on the Aircatch website so that you can check that out if you want to as well. Just a little plug there. Yeah, good stuff. Do check out our website, aerocoach.com or.co.uk. .co.uk, but yeah, thank you. But with the tyre thing you mentioned there, doing road races on the time trial tyre, are the gains for you there because the tyre is lighter or are the gains because the tyre has better rolling resistance?

1:00:49It's better rolling resistance. Obviously, with some time trial tyres, you'll have slightly less grip but i haven't really come up on the limits of grip certainly the races that i do um so i ride a conti 5000 tt 28 mil tire in a road race on a set of our wheels which are about 78 mil deep and they this 28 mil like you can really there's like a big contact patch you can really lean the bike over and it's it's absolutely fine and i've rode races on the Pretorias as well in 28. But the Conti's I found to be absolutely brilliant. And it's just down to wrong resistance. It's just so much lower than the Conti 5000 standard tire, especially when you then put the right inner tube in it or whatever.

1:01:33And one thing about tires I would say is that we've moved away from tubeless in recent years. So you can run tubeless tires with inner tubes in them if you want. And that's what I do. And I know people are like, oh, but tubers can save you in the event of a puncture and things. It's like modern tires are so good that it's not like it was back in the day when I was time trialing in mid-2000s and things were made of paper and you just sneeze on your tire and it explodes at you. These days, I just don't think the tubeless is as necessary. TPU tubes are quite punctured impact proof. Latex tubes are a bit less so.

1:02:12So I use TPU tubes for road racing, but latex tubes and it also means you can change your tires out like a lot easier than you would do if you had tubeless setup and if you if you if you look down the list like let's say you go for a group rider and you go to each of the riders you tell you ask them the question how many milliliters of unevaporated still liquid tubeless sealant are in either of your wheels no one has the answer to that yeah absolutely no one for some people the answer will be zero because they haven't changed things and so your tubeless sealant's doing absolutely nothing because it doesn't exist anymore because they have to change their tyre for ages.

1:02:46Some people, it might be 60 milliliters, which is slowing you down because it's too much slopping around there. I know that's a bit of a tangent, but yeah, I feel as though tubeless is just... And I think people at manufacturers are kind of getting... Not manufacturers, but everyone in the cycling industry is kind of realising that tubeless isn't the be-all and end-and-all. Certainly with issues with using hookless and people not knowing what pressures to pump things up and tyres flying off hookless rims and all this kind of stuff. Our new wheels like we haven't made a hookless wheel yet or probably ever will to be honest because it's just a bit of a my feel um but anyway yeah so getting your tires rise important that's like number one from a speed up your bike point of view uh wheels are good uh and and wheels yes they can be expensive but if you're going from something that's like a really shallow aluminum rim that might have come with your bike when you first bought it or something like that to a deep section wheel of sort of 50 60 mil carbon fiber kind of the right you know shaping that that will make a a solid difference they also make quite a nice noise if you're up to speed yeah i mean that's again playing that psychology of it right where you feel exactly feel fast so you go fast yes yeah exactly i was just going to say with wheels there's a kind of newer shape that we keep seeing the variable height rims, Princeton sort of, I don't know, did Princeton pioneer it?

1:04:08And then it's been ripped off and I don't know, whoever there's, anyway, variable height rims where it kind of is a wavy profile. We're seeing more and more of those. I wouldn't say they're ubiquitous, but they're more commonplace. Is there something to them? Or is that realistically just a way of making something look different? So it feels like you might need it, like it might be better because it's visually impactful yeah so obviously visually there is a it's a design cue but we've never seen a variable height room outperform something else of a similar depth that's like that doesn't have it and all the stuff about handling and things i mean i don't know if you've written a zip i think there's a zip for the ones who first yeah utilized it but it was based on a patent that's owned by Zemecius Katsanis from Metron.

1:05:00Oh, that's right. Yeah. And then there was all sorts of legal issues when Princeton designed a wheel that looks very much like one in the patent. So if you've ever rode the set of those 454s, they're pretty sketchy in the wind because I had some. Because initially the idea was that it was just going these slightly better handling and yes all this stuff about error whatever but like one of the things was about how they were better to handle and i've just not seen that we haven't had the feedback from riders on any of these variable wheels whether it's princeton wheels or music or anything like that that they're suddenly it's like a revolutionary thing for handling yeah um so i think yeah there's there's a bit of a design few thing to it uh i think i saw some i've read some stuff somewhere where people were claiming more about spoke tensions and how making the Spoke length is shorter if you can get spoke at the lower point of the rim, if that makes sense.

1:05:55And there's a bit to that as well, but it's all relatively marginal. And then you've got loads of other companies, quite far-eastern companies that are doing shapes like that, and Fulcrum have done it with their shark wheels. Yeah, that's right. And yeah, I think you'd need to have a reason to do it. So if you're doing it and the design that you've done has made the wheel more aero, great. but we haven't seen that these things suddenly outperform everything else from an error perspective. The new time trial wheels that we've made don't have variable section room. We had a go. It didn't really work.

1:06:29So we didn't bother. There was no need for it. But there might be something that, from our perspective, there might be something that we do in the future that has variable room depth because we find that it has an impact in a positive way. but right now we haven't found it in our own testing um that's not to say we won't but like yeah um but currently no um but i'm not ruling it out so yeah but it's definitely interesting and and obviously people have jumped on the bandwagon and saying that we'll make things that look like that without any testing whatsoever um just to make it yeah just to make something different and what's what's your sort of feeling on aero socks and as a supplementary question to that if indeed there is something to them why aren't riders you know looking for absolute speed at all costs despite maybe heat management being a factor wearing not just skin suits but all in one very very thin onesies like you kind of saw appear in swimming for a while and i'm not sure where they got to in swimming but there's a point where they kind of ended up having to pull back on them wasn't there because it's basically it's like you can't dress like a mer person and do the you know It's just not on.

1:07:42It's not fair. Yeah, so the one-piece swimsuit things, they basically, yeah, because people were going too quick and they were adding different buoyancy punches in and stuff and it was just making a bit of a joke in terms of the speed you could go from a buoyancy perspective. So they got rid of those. With Aero Socks, so you can't cover, unless there are adverse weather conditions which allow you to wear knee covers and stuff like that, you're not allowed to have a full onesie. but you can have a skin suit. I have a custom skin suit that I use for road racing with some pockets in the back and I road race with overshoes on because you're allowed to do that.

1:08:20And you can do that on the track as well. They did ban overshoes on the track. I don't know when it was, say, before Tokyo. It was banned before Tokyo and then they got rid of it. It was banned from London or something and then they got rid of the ban. Something like that. Anyway, the UCI relented on that so you can now wear overshoes wherever you want. and they make a big difference. And Aero Socks do. I mean, certainly if you've got hairy legs, like it's covering up a load of hair, so that helps. But yeah, Aero Socks are a decent win. I mean, you think about, and we use the example of a down tube of a bike.

1:08:54So you're looking at a bike that's dead on, right? And it's quite a thin shape. You can barely see any of it. You see some fork legs, the front wheel, the head tube. You think about how thin the down tube is. And then if you imagine a pair of legs either side of the down tube, and they're comparatively massive you know let's say but to potentially three four five times the width of the down tube per leg and if you if you said to someone right we're going to now cover your down tube in hair then you say well i'm never going to buy that bike because it's going to be the most unerror thing possible like no one would ever touch that but people have this allergy to thinking about leg aerodynamics in a similar way so obviously shaving your legs makes a massive difference and if you make your the the surface of your leg more aerosinamic it will also make a difference because it's such a big shape uh we see this with paracyclists so if you're if you have a below the knee amputation on one side or both sides and you have a prosthetic leg and i've done a peer-reviewed scientific articles on this if you take a prosthetic leg and you change the shape of it even slightly makes a massive difference really so the that's the going back very much to what we're talking at the start of this podcast about pressure drag and friction drag.

1:10:08Pressure drag, by changing the shape of your leg, by putting an airfoil, let's say you're a cyclist and you have a carbon fiber leg, this big airfoil wing, that makes a huge difference. But a general cyclist can also, you can't really do that, but a general cyclist can also change their friction drag by putting an aerodynamic surface on their leg to allow the airflow to slip over it more efficiently. So yes, aerosocks make a big difference. You have a big thick cotton sock where the airflow is just not going to, blow over it and create the same kind of drag as if you have. Generally speaking, a lot of companies have a similar type of stock design, which is like a stripy fabric, Lycra, that's tight to your leg, that comes halfway up your leg, that sort of thing.

1:10:51Yes, absolutely do it. Yeah, definitely. And if you want to go really quick in a road race or TT, bring some overshoes on so you can cover up all the buckles on your shoes and make everything super slip. That's what I do. That's what I think is the fastest thing. I was going to say, would you ever canvas for not wearing socks at all? Surely, completely shaved human leg with just like the tiniest little kind of pop sock some sort of transition to cover over those bowed out dials and go over the ankle would be super fast or are the fabrics of those socks actually faster than skin? Yes, the fabrics are better than skin at row speeds.

1:11:29There is some indication that you can that that might change a little bit at higher speeds because the friction drag requirements are a little bit different. And you start going into things called Reynolds numbers, which are basically an indication of how the airflow moves over a surface. And your Reynolds number will change depending on the speed. And there's like kind of tipping points where the Reynolds number changes so much that a particular type of surface texture is really good. High Reynolds numbers are really bad at low Reynolds numbers. But for a general road cyclist, skin is just not good.

1:12:04It's not aero. Certainly on your legs, facing the sort of, yeah, in that kind of shape area. There's some indication that you can kind of get away with it, like, you know, Evan Paul not having arms on his skin suit, but his arms are kind of covered by his extensions. And that's the kind of famous example, which is going to bring it up. But his arms are covered by the extensions a little bit and are at a different angle and things. But generally speaking, like every single fabric that we've tested on your leg is better than their skin. Yeah. In a kind of normal scenario, we normally test at 40, 45k an hour.

1:12:34Actually, the lower you go, it makes a bit less of a difference. But yeah, I wouldn't go post-op if you want to go quick. And you saying Reynolds number has made me realize we've gone through a whole podcast about aerodynamics, I think without saying CDA, which is often kind of used. Yeah, often used as like the metric. So power, once upon a time, it was heart rate. then power meters came along and screw your heart rate doesn't matter it's just all about the very raw data you know the very objective data of how much power you're putting into your into pedaling now cda way more important and then we see lots of companies and i mentioned at the top of the show i did some stuff with trialing the body rocket system so on bike drag measurement systems no show is another one i'm not sure if they're still around that was one of the early ones there are more there was a french brand that just popped into my inbox the other day that promised to reveal some man anyway oh i know this one's um yeah yeah i mean yeah yeah and and just to kind of flesh this out for people who haven't seen it like with the body rocket system i was sat on a bike had a regular head unit it had various sensors on the bike and the head unit had one number a one of the fields had a number in it which was my cda um which was good i don't know 1.8 or something like that and the smaller that number I was told effectively the more aerodynamically efficient I am because I've got a smaller frontal area bigger the number worse off and it sounds compelling because to look at a screen and see one number and go right I just need that to be lower and keep it there that's quite a kind of seductive proposition but what's your thinking on those systems are are they the future will we one day see that integrated into head units you know for example wahoo already has this thing with the ace which is a similar kind of wind speed censoring sensor but i'm not sure if it's quite utilized to that way yet but do you think that's coming and if it does will it ever be useful like power meters are useful or is this all just you know it's going to be a bit of a storm in a teacup So people have been trying to do this for ages.

1:14:47So we worked with Alpha Mantis, which was a company that made one of these Aero sensors well over a decade ago. It was doing exactly the same thing that these sensors are doing now. Not very consistently, but that was the idea of it. Alpha Mantis got bought by Garmin. Garmin wanted that technology, and they now don't use it. We've had discussions about this with Garmin and things, but you need to have a think about Why are they not using that? Yes, at least. And we've got, you know, we've had AeroPos, Notio, we've got Aerosense, we've got all these things that come out. We've had a plate. So the body rocking device that you mentioned doesn't measure the track of the bike, which is why your CDA is coming out at 0.18, because that's very low.

1:15:30That would be as if the bike is invisible. It only measures the rider. So if you make an adjustment to your bike and you put a different wheel on something, it has no idea what your CDA changes. So it's just measuring your body position and giving you that so you will be able to test like kit. But there are other things that will report to give you a CDA value that's consistent that you can use to make yourself faster. But then you have to think a little bit further down the line. And if you know where your CDA is, what are you going to do with that number? So let's say you have a road bike and you find out that you hold the hood so your CDA is, I don't know, 0.29 or something.

1:16:08That might be like a typical number for someone sort of sat up right with a normal kit on. and then you get into the arrow hoods position and it's 0.26 because you've got a bit more, you know, a bit more arrow. That's great. Now, are you going to have that, let's say you're doing a road race, are you going to have that in front of you so that when you're off the front of the group, you're making sure you hold that 0.26 position and you don't lose your position? That'd be great. What if someone slips in behind you? As we discussed 45 minutes ago, that's going to lower your track. And so that CDA number is now going to be completely inaccurate.

1:16:42What if you're sat in a bunch and your CDA goes down to 0.08? Because that's what will happen when you're sat behind a ton of riders. That number is now completely pointless to you. And so if you're not using it in a racing situation, because it's just going to move around too much, regardless of what's happening with your rolling resistance, because these devices have to assume a constant rolling resistance, unless they're using vibration sensors, which not all of them are, to give you a CDA value that's consistent. so let's get rid of that as a problem as well let's assume that they've figured that one out and you're you've got one of these devices it tells you what your cda is what earth are you going to do with that are you going to go out and buy 20 sets of wheels and then test them all using your sensor to find out which one's more aero and then what put them on ebay later having lost thousands of pounds worth of investment doing that are you going to buy a load of different skin suits are you going to buy a ton of different helmets i mean road helmets these days like two 300 pounds each like that's a massive wad of money i just don't see if you're if you're a coach or something you have a load of athletes and you can put these on one of your athletes and you have a stock of all this kit you can help them work through some options then that's great if the devices work right and that's just still a question um but i think to the general consumer it's not same as a power meter and i i worry that these companies are putting a lot of investment into these sensors are thinking that it's going to be the new power meter, which was the new heart rate at the time.

1:18:10And you gave a great example of how these things have moved around. It's not heart rate power CDA. CDA is like a massive side project. I'd say that things that'd be more useful for people are like the sweat sensors or carbohydrate oxidization devices that can measure, not have to go subcutaneous to measure how much carbohydrate are using lactate measurements that don't exist yet quite that will have been able to lactate without having to have invasive measurements. Those are the next step on the heart rate power scale. The CDA sensors, and we've got the Wahoo Element Ace who bought one of those.

1:18:45The wind sensor on it just tells you what the wind is when you're going along. It's completely useless. You can see that they've done, well, I assume what they've done is they've put the port in there so that in X number of generations' time, that thing will give you some kind of a CBA number. But how it would be accurate, I don't know. Changing wrong resistance out on the road and hitting potholes and moving over different surfaces constantly is such an issue when it comes to trying to calculate your CBA because it has to account for it. And very few things can. I always think that that's the problem that no one has even bothered trying to solve yet because everyone's too interested in showing how clever they are at measuring a CBA value or getting the CBA number on the screen.

1:19:27As you say, it's very compelling. It's a new number on the screen. It's very exciting. But it's also another thing that you have to then have in your head if you're trying to use it from a performance perspective. Let's say you're doing a time trial that's a bit more controlled and there aren't people drafting you and you're trying to hold a nice position and you want your CDA to go down as low as possible. What else are you trying to focus on? You're trying to focus on your cadence to make sure it doesn't go too high or too low for your optimal range. You're trying to focus on your power output because that's kind of the most important thing.

1:19:54And then, oh my God, suddenly I've got to worry about my CDA as well. and you've suddenly got all this information that's just trying to, you can't process it because your brain's going a zillion miles an hour trying to push down on the pedals. You could have a situation where you're just using a red light, green light system. Are you in the right position? Yes, green. Are you not? Red. Happy days. And some senses will do that. But there's a lot of inputs going in, and I think that the advent of these senses isn't the advent of senses that people are claiming that it is because they've existed for ages.

1:20:24And the notion, if... If these things were going to be ubiquitous, the no-show would have taken off, but it didn't. And not because the numbers aren't great, and they aren't great, but because people aren't buying them and using them. And it's been around for ages and ages. Albany team is still supporting it. You still get the app for it. I don't think anyone's selling them, really. But we had a couple. We still kept one, and you can still use it if you want to. It's not very accurate. But the fact is it's not very accurate. We know it isn't very accurate. but no one's screaming about it. It means that no one's bought them.

1:20:59Yeah, I see. And you go back to the amount of money that's being sunk into these CDA sensors without thinking that extra couple of steps down the line, is there a market for it, like a big commercial market for it, in the same way that a power meter is ubiquitous and nearly everyone working past a particular level of involvement in cycling as a hobby, most people will have one past a certain point. it's not in that realm and i am continually frustrated by people who don't recognize that recognize it for the kit that it is as a tool that can be potentially used in some situations but a very specific kind of tool like we don't use them for our customer sessions and there's a good reason why yeah you know like we would do that if they were great we'd be using them and we'd be championing them and it's great whatever but we don't and there's there's there's obviously a reason for that.

1:21:55And it's tricky as well because you get the number on your screen and you're going to trust it. It's just the same as if you see a graph. Like you see a graph on a website or some kind of chart with some numbers on it. Like instantly you have a trust for that because it looks like data and it feels like something. Someone could have lied about it and made it up or whatever. It's the same thing with a CDA number on the screen. Like you have no idea if it's accurate or not. And we've seen people say, oh, I've I've got a component or a new helmet or something. I've tested it and I know that it's A, better or B, worse or C, the same or something.

1:22:31And you see people saying on social media and I'll test it. It's like, have you? Like probably if you've been using one of these sensors, you might not have done. Or your testing might not be that consistent or your test protocol might not be great. It could be wonderful. And if you're a very diligent tester and you have understanding on how to do a rigorous scientific test, then you might well have tested this thing and found all this great. But it comes circles back to what we were saying previously about misinformation and not misinformation because of the danger mouse toad, the evil person.

1:23:03It's just misinformation because that's just what's happened. And I worry that people who've got these sensors who are not using them correctly or think that they definitely are but aren't using them correctly or the sensor is terrible in the first place or the environment they test is wrong. They test something, they think it's worse, and then they have that information, that data, and then they use the thing that actually would have been speeding them up and chuck it in the bin. So it's tricky. So yes, I'm not convinced that the aero sensor market is something that's going to suddenly take off because these companies have been around for a while.

1:23:39Some of the companies you've mentioned that we've talked about have been around for ages, but I'm still not seeing them on everyone's bikes. and if Wahoo just stuck a little hole in the front of their head unit and it's doing nothing, that's a big company to do nothing with. I'm not being facetious about it. I'm making light of it. But it's not the thing that everyone is claiming that it is. And I'm not sure if there's an avenue for that to be the case at the moment anyway. So I wouldn't recommend that people think that they have to have one of these devices. Obviously, it would probably appear that I'm coming from a biased perspective because we run error sessions and like, oh, forget these sensors, you've got to come and have an error coach session.

1:24:30That's not the case. That's not the case at all. If they worked and if we thought there was value in them, we'd be using them. and currently we've got them and we're still trying to figure out things that we can do with them that are interesting. In terms of wrong resistance, it's quite a good one actually. But right now, yeah, it's not part of our commercial package and there's a reason for that. So in conclusion, to go faster, sit behind your mate, do some yoga, wear some speed socks, don't sweat the emperor's new clothes, avoid variable rims, stick with tried and tested shapes don't worry about a bike frame possibly a hole in the front of your helmet um and ultimately ultimately just kind of buy the thing that makes you feel like you want to go and cycle it fast that is the most important part of it it really really is and and and i think that there's there's no point stressing and we gave the example of the pro cyclist stressing about the thing that they've been forced to ride or whatever you will go faster all things being equal if you're riding something that you're happy you're doing I mean I've got a new road bike this year I've tested it to see if it's faster than the old one but I like it and that's fine you know obviously if I test it is terrible I will swap back but but everyone shall remain blissful well exactly and I've seen you going all right in this so far so um but it's definitely because cycling is an emotional sport don't turn it into something that that feels like a job or feels like, you know, anything.

1:26:04Yeah, I don't know how it quite to get the words across, but like don't turn it into a chore, all of this stuff. Yeah, that's what I really want to get across. It should be fun. And if fun means that you don't want to shave your legs, don't shave your legs. Like that's fine. And whether you understand that it's a little bit slower or quicker, it doesn't matter. Just as long as you're enjoying yourself because that will make you a better athlete at the end of the day. You'll ride more and that's all you really want to do anyway. Fantastic perfect place to end on thank you so much Xavier and sorry I've kept you way longer than uh than advertised um but yeah fascinating chat and hopefully yeah we'll have you back on podcast at some point in the future because I feel like you're a font of knowledge way beyond aerodynamics we can discuss the width of tires next that's one of my favorite subjects

1:26:53and I'm back and that was Xavier Disley ladies and gentlemen that was quite a long interview so So I'm going to just leave it there. Suffice to say, thank you very much for joining us on the Cyclist Magazine podcast. We'll be back in two weeks. And until then, just a light in the mood from what was quite a dense aero chat. A few more jokes from Cyclist Magazine. Because we're a magazine. We are a beautiful magazine. Look at the cover. You can't hear it. I mean, you can't hear a cover? Yeah, you can't hear a cover. So I'll describe it to you if you're not watching this on YouTube. There's three riders.

1:27:26They're on a road. The road seems to disappear and some mountains very high up. It looks inviting. It looks like the sort of place you want to be. And I want to be. Anyway, so a few more little jokes. Those who doubted orthopedic shoes now stand corrected. What did the drummer name his two daughters? Anna 1, Anna 2. Did you know Vin Diesel only eats two meals a day? Break fast and break furious. and finally bin men are rubbish drivers although I do have one more and this is from my own personal joke arsenal because everyone should have one 14 and a half psi goes into a bar right on that note that's goodbye from me and goodbye from me and see you guys and hear you guys and talk to you all those things sensory overload in another two weeks bye

1:28:23Hello, lovely listeners. I just wanted to tell you that Cyclist isn't just a podcast. No, Cyclist is also a beautiful print magazine. It's packed full of all the best rides from around the world, the newest bikes and kit, and loads of in-depth articles featuring guests, just like on today's show. So head on over to cyclist.co.uk slash subscriptions and check out our latest cyclist magazine subscription offers