Login required to started new threads

Login required to post replies

Prev Next
Dennis Rohan position & 175 cranks
Quote | Reply
Doesn't look very aero to me! Also 175 cranks what is his fit coach thinking?

Discuss
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
Over a short pure time trial power output advantage outweighs aero to some extent depending on the rider... Shorter cranks you can get more aero at lower power outputs and helps your run in triathlon.
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
thatzone wrote:
Doesn't look very aero to me! Also 175 cranks what is his fit coach thinking?

Discuss
He's world champion so he is right and slowtwitch is wrong?
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
That would be Rohan Dennis.
Quote Reply
Re: Dennis Rohan position & 175 cranks [Bianchi928] [ In reply to ]
Quote | Reply
Bianchi928 wrote:
That would be Rohan Dennis.

He was so fast his first name had to settle for 2nd place.... (I'll show myself out....) :)

Shane Miller - GPLama
YouTube | Web | Twitter | Instagram | Facebook | Strava
Quote Reply
Post deleted by Administrator [ In reply to ]
Last edited by: gabbiev: Sep 26, 18 18:56
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
OK, he's around 6 ft tall....175's don't seem like they would be too bad. Normann Stadler had the Kona bike course record on 175 cranks and held that 4:18 split record until Wurf+Sanders+Kienle beat it on a perfect day (Normann had a perfect day in 2006 too). Also Kienle ride 175's and is around the same height as these guys.
Quote Reply
Re: Dennis Rohan position & 175 cranks [gabbiev] [ In reply to ]
Quote | Reply
Is it just me, or the camera angle, but does his femur look abnormally long? Not a fit expert, but I suppose I can see how 175 might work well for him.
Quote Reply
Re: Dennis Rohan position & 175 cranks [Jason N] [ In reply to ]
Quote | Reply
Jason N wrote:
Is it just me, or the camera angle, but does his femur look abnormally long? Not a fit expert, but I suppose I can see how 175 might work well for him.

I think abnormally short tibia is really what is needed to operate well with long cranks, in the sense that if you have a short tibia and a heal down pedaling style, it leaves an open hip angle at the top of the pedal stroke.
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
thatzone wrote:
Doesn't look very aero to me! Also 175 cranks what is his fit coach thinking?

Discuss
You can get away with a lot when you don't have to get off and run.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
Quote Reply
Re: Dennis Rohan position & 175 cranks [gabbiev] [ In reply to ]
Quote | Reply
I said the same thing when I read this..the guy destroyed the field today, has been consistent all year and this guy says that...I’m willing to bet his CdA numbers on the track and tunnel are spot on. his head position with the aerohead look great.
Quote Reply
Re: Dennis Rohan position & 175 cranks [trentnix] [ In reply to ]
Quote | Reply
trentnix wrote:
thatzone wrote:
Doesn't look very aero to me! Also 175 cranks what is his fit coach thinking?

Discuss
You can get away with a lot when you don't have to get off and run.


From the weak evidence of static visual inspection and watching some video, he looks comfortable, powerful, aero AF, and completely at ease with his position.

I don't know what, exactly, he's getting away with, except the gold medal.


Quote Reply
Re: Dennis Rohan position & 175 cranks [trail] [ In reply to ]
Quote | Reply
My point was that the type of riding he's doing isn't really negatively impacted by longer cranks. And as has been pointed out, his morphology seems to allow him to preserve an open hip angle despite the crank length.

That doesn't diminish the reality that shortening cranks can provide significant benefits for triathletes (and others riding long distance at generally steady states) looking to open their hip angle, reduce knee flexion, and ride more comfortable.

This isn't a statement about the position or equipment of the rider in question: many championships have been won on inferior equipment and inferior positions. And that a rider has great success doesn't mean there aren't opportunities for additional improvement.

Trent Nix
Owned and operated Tri Shop
F.I.S.T. Advanced Certified Fitter | Retul Master Certified Fitter (back when those were things)
Last edited by: trentnix: Sep 26, 18 20:04
Quote Reply
Re: Dennis Rohan position & 175 cranks [trail] [ In reply to ]
Quote | Reply
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
Not an accurate representation, but I thought Tom Dumoulin looks better?.
Quote Reply
Re: Dennis Rohan position & 175 cranks [trentnix] [ In reply to ]
Quote | Reply
trentnix wrote:

This isn't a statement about the position or equipment of the rider in question: many championships have been won on inferior equipment and inferior positions. And that a rider has great success doesn't mean there aren't opportunities for additional improvement.



I accept your points in general, though I'm somewhat skeptical of short cranks.

And you're right about the above, generally speaking. But as a student of pure TT, there are few who take the craft to the extreme of Dennis Rohan. He is not the genetic superstar who can just blow people away with sheer power on any old equipment. He is the marginally talented guy (for a World Tour cyclist) who scrapes every last inch of the barrel so out of 10 tries he can shock the world once or twice.
Last edited by: trail: Sep 26, 18 20:15
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
he's not into his aero position in that pic. notice how one hand is on the basebar? he's either sitting up for a corner or settling in after the start or a corner.

Swimming Workout of the Day:

Favourite Swim Sets:

2020 National Masters Champion - M50-54 - 50m Butterfly
Quote Reply
Re: Dennis Rohan position & 175 cranks [devashish_paul] [ In reply to ]
Quote | Reply
devashish_paul wrote:
Jason N wrote:
Is it just me, or the camera angle, but does his femur look abnormally long? Not a fit expert, but I suppose I can see how 175 might work well for him.


I think abnormally short tibia is really what is needed to operate well with long cranks, in the sense that if you have a short tibia and a heal down pedaling style, it leaves an open hip angle at the top of the pedal stroke.

What about the foot size? I'm pretty similar to these guys in that I have long legs and sz12-13 feet. You'd think that a larger foot can tolerate larger size cranks. Riders with short legs and small feet need to tighten up the space - re: kids bikes.

I prefer 172 or shorter (I guess, never tried) I know that 175 is too much.
Why is it not understood, in general on ST, that is there no "one" setup or position. eg I had a sprint bike, a "GT" bike and yet another setup for training/street. Low and slightly more compact vs raised up and a little more room.

Training Tweets: https://twitter.com/Jagersport_com
FM Sports: http://fluidmotionsports.com
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
I wouldn't say that...

http://www.cyclingnews.com/news/dumoulin-physically-im-a-broken-man/
Quote Reply
Re: Dennis Rohan position & 175 cranks [thatzone] [ In reply to ]
Quote | Reply
Lol. The internet is a funny place.

Jim Manton / ERO Sports
Quote Reply
Re: Dennis Rohan position & 175 cranks [Jim@EROsports] [ In reply to ]
Quote | Reply
Jim@EROsports wrote:
Lol. The internet is a funny place.


Hmm... I don't necessarily think that just because he had a dominant ride that there's no way that he couldn't have been even faster in another scenario, or that winning a world championship means he exercised INFALLIBLE judgement with his setup, but even if he did, speculating on position changes tends to be fun and interesting, so...

If he was a person who posted pictures of himself on slowtwitch and asked for help in eeking out another aero gain, I'd probably tell him to try to scoot his seat forward a little bit and then pull out a spacer or two to get a little bit lower. That certainly seems like it would make his position look a little bit more like Dumoulin's and Martin's old position (at his peak). If he asked you for hints on what you thought could get him a bit more aero, what would you tell him? I imagine that with all the data you've collected you have much better instincts and insights than I do.
Last edited by: LynchDeez: Sep 26, 18 21:21
Quote Reply
Re: Dennis Rohan position & 175 cranks [LynchDeez] [ In reply to ]
Quote | Reply
Remember he is confined by UCI regulations and seat could well already be at it's forward limit for his fit regarding his extensions... I guess all the experts in the wind tunnels he tested at including Giro developing the Aerohead around him should have consulted slowtwitch...
Quote Reply
Re: Dennis Rohan position & 175 cranks [Shambolic] [ In reply to ]
Quote | Reply
Shambolic wrote:
Remember he is confined by UCI regulations and seat could well already be at it's forward limit for his fit regarding his extensions... I guess all the experts in the wind tunnels he tested at including Giro developing the Aerohead around him should have consulted slowtwitch...

Since he was working with all those experts, and all the other top time trialists in the world were working with their own experts, wouldn't you expect them to reach conclusions that were far more visibly similar to each other? If not, what do you think the major differences are in their morphology that lead them to have such different positions? I know Dumoulin is taller than Dennis, but I would have guessed that Martin was much closer to his height.
Quote Reply
Re: Dennis Rohan position & 175 cranks [Jim@EROsports] [ In reply to ]
Quote | Reply
Jim@EROsports wrote:
Lol. The internet is a funny place.

lol, come on Jim. Give us some internet commentary. That's what we're here for. Say Dennis wants to win by 2min next year. How can he improve position/setup? Wink

https://www.strava.com/athletes/nbrowne1
Quote Reply
Re: Dennis Rohan position & 175 cranks [LynchDeez] [ In reply to ]
Quote | Reply
Then you would have given him very poor advice.

Jim Manton / ERO Sports
Quote Reply

Prev Next