I was busy in June and did not follow the Daupine in depth but heard he was experimenting with 160’s. Is that on his road and TT bike? I could not find a good image sideview of his hip angle from Wed, but here’s another one but I don’t know what the crank length was.
He’s supposedly on stuff as short as 150…since February
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Not sure about Jonas, but Pogacar was on 160.
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OK so here Sir Bradley is saying that Jonas was on 155’s and they are saying he was on a 68 tooth chainring!
Someone correct me if I’m wrong, but do all 3 of these guys not understand how gearing and crank length works??? I mean practically even if he has a 68 front, what if he is in a 23 in the back? They talk about torque but I never heard one word about power or aero…
Probably not 
I heard or read that Jonas was on 150mm for TT and 160mm for road, but I can’t remember where I got that from so could or could not be correct.
I’m pretty sure the broadcast listed Jonas as being on 64T chain ring and Roglic on 68T chain ring. IIRC SRAM has 60T, 64T, and 68T TT aero rings so I’m guessing most of the SRAM teams were using either 64T or 68T.
Yeah force x distance gives torque then RPM gives power. I think Bradley gets that it just did not jump out. Perhaps what Bradley was alluding to when he talked about “leverage” is if you lose “leverage” (which would be distance in the force x distance torque calculation) because of the mechanics of how an individual applies force and you’re not also overcoming that with higher RPM, then that’s a power loss. I can’t imagine that Jonas is losing any force application on 150s or 160’s or 170’s but at some point are his RPMs not minimally overcoming the reduction in crank length? If he also manages to lose force due to his biomechanics being limited for force application on a shorter crank, and he can’t overcome both the loss of force and the loss of lever length with even more RPM, that’s a net loss.
But I thought somewhere else they are saying Tadej and Jonas are both putting up the mythical 7.2W per kilo earmarked by Ferrari sending riders up Col de Madone TT, so it does not sound like Jonas is generally losing power, he was jusst off on TT day (or less aero)
Well it didnt seem they understand any of that, and what does the teeth on the front chainring have to do with anything power related?? Just seems they are arguing in the 2000’s and not 2025 tech and knowledge…
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I think Bradley in other venues has shown he understand the physics. I THINK he was questioning if Jonas is able to apply sufficient crank force (he used the word leverage, but I think he meant crank force) at the smaller crank length. If your crank force goes down because you can’t use an appropriate muscle range, its a double penalty because you have a short crank meaning your torque went down from less force and less lever and the only way to get back to the same power is even higher RPM.
None of us have a clue if Jonas’ crank force went down so much that he can’t overcome that with even higher RPM. We all know from weight lifting there is a sweet spot for any exercise when we can recruit the best biomechanical advantage, but that’s on fast twitch fiber. It may not be material at the tiny low muscle forces in aerobic activity. Or it may be accrued over many reps per minute. I believe in the link provided by @Yutaka_Sonik above some of this was discussed and perhaps Bradley was alluding to that.
Agreed, number of teeth makes zero difference, but Bradley also talked about gear inches which is all that matters
It’s kind of hard to take an article seriously when it includes stuff like this:
At a simpler level, a set of shorter cranks will result in a higher cadence to spin the same gear ratio.
The cadence required to run any given gear ratio at any given speed will remain constant regardless of the length of the crank. Pedal velocity will change, but - ouch! - it actually increases in proportion to the crank length, as the foot must move a greater distance with each revolution.
Shorter cranks tend to drive riders towards higher cadences because the foot moves slower with a longer crank, and humans seem to generally try and keep their foot speed in a small(ish) range that more or less directly correlates to muscle shortening velocity.
So, yes… I think this is probably well in line with what Bradley was trying to get at. And it’s definitely not indicative of an understanding of the physics/physiology.
To the part in bold,
if you go from 160 to 150 cranks, all gearing got 160/150 = 6.67 larger, But crank torque = F x d got 6.67 percent smaller. As the size of gearing does not play into power, the only thing here is that the rider keeps the same crank force ideally so that Torque is 6.67 smaller and then increases RPM by 6.67 percent so they end up with the same power.
I guess we don’t know if Jonas’ power was better or worse on 150’s and we don’t know if he was less aero or more aero than previously. If he is more aero than previously, and minimally if he kept RPM similar then his torque was down and he had less power, of his RPM when up and he delivered less torque due to smaller lever and/or less crank force.
Or its all just a wash and he just had a bad power day unrelated to the crank length.
Are there stats somewhere from his ride (ave power, ave RPM etc)
No.
Get yourself a fixed gear track bike. Push it 100 feet. Count how many times the cranks go round. Cut the crank arms in half. Push it 100 feet. Count how many times the cranks go round.
In this universe, the answer is always going to be the same; crank length does not change gear ratio, and cadence is not changed by variance in crank length.
You’re confusing gear ratio with gain ratio. They aren’t the same thing.
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I meant gain the overall gain/gear effect. Crank length is part of the overall calculation for gain (it’s part of the gearing although never calculated in gear ratio and wheel size is also not calculated in gear ratio either, but its part of gain too). In you example if you walk the bike around and cut the crank in half you’d have to put double the crank force to get to the same power, all other variables being equal
Yes. That’s called gain ratio. It’s well understood, just - apparently - not by people like the CN writer and Sir Bradley.
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