Track Crank Length

tafi

Do you have a high bottom bracket for this?

VeloFlash

I have a 50mm BB drop measured as the distance below a horizontal line drawn between the rear and front wheel drop outs. I would think this would be about standard for a track bike.

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VF

"Remember, even if you win the rat race, you are still a rat"

smurfbike

This may help in your decision ... Brad McGee now uses 175mm on both road and track after using 170's on the track, in earlier years.


Jacques Anquetil 175mm
Lance Armstrong 175mm
Chris Boardman 170mm
Santiago Botero 172.5mm
Angel Casero 175mm
Mario Cipollini 172.5mm
Fausto Coppi 171mm
Malcolm Elliott 172.5mm
Tyler Hamilton 172.5mm
Bernard Hinault 172.5mm
Miguel Indurian 180mm (190mm for second Hour record!)
Laurent Jalabert 172.5mm
Greg Lemond 175mm
Brad McGee 175mm
Robbie McEwen 175mm
Eddy Merckx 175mm
David Millar 175mm (180mm in TT)
Francesco Moser 175mm
Marty Northstein 167.5mm in Keirin (170mm in kilo)
Graham Obree 175mm
Marco Pantani 170mm (180mm in mountains)
David Rebellin 172.5mm
Roger Riviere 175mm
Jean Robic 170mm
Tony Rominger 172.5mm (175mm for Hour record)
Oscar Sevilla 175mm
Jan Ullrich 177.5mm
Rik Verbrugghe 175mm
Erik Zabel 172.5mm
Alex Zulle 175mm (180mm in mountains)

wavydavy

This is interesting, apparently I should be on 175s

http://www.highpath.aaugonline.net/cycles/03.html

franklin pierce

I do not exactly know about track per se, but I've run 165 and 170 on a road fixie and the 165 seemed to spin better, even made hills easier in a bigger inch gear. Then again, I'm only riding an 82ish.

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Sorry, English is not your primary language.

taras0000

I have experienced the same thing, even in larger gears. like a mentioned earlier, probably due to the fact that your hip is in a better position to transmit power.

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Taras

ed073

Robbie's on the long levers for such a short-arse.


Seems to be working though.......

jingerebir

In general physics suggest that several factors that come into play.
1.) Length of tibia.
2.) Length of fumer.
3.) And the ratio of the above and total lenght of leg.
4.) Along with Seat position. Angel of pelvis.
Best Power etc Bla Bla Bla Physic Physic Bla Bla.
====================================================================== ==========
In real terms it boils down to the following.
1.) Almost all short riders will most likely always be best served by 165 mm cranks. (rider < 5'5")
2.) Taller riders will be best served somewhat longer cranks most of the time. (rider > 5'8")
3.) Loss of significant power through body contact. A rider who's upper leg contacts their body at the top of there peddle stoke will prefer a shorter crank. In other words (Huge thighs or short fumer/long tibia then shorter cranks eq good).
4.) No one wants to lift the back wheel off the wood (shorter cranks and higher BB eq safety). However 180mm cranks with a 4.0 cm BB drop could be just about as safe as a 5.5 cm BB drop with 165mm cranks Remember 1cm is 10mm.
5.) Not to many people will feel to good about spinning 1000 miles in pre season with 180s only to switch to 165s on opening day at the track. (Comfort,training,better spin,etc eq better power)
6.) Lower BB is a little more stable. Do you need to face off and jockey for position during a sprint at low speed or is you race greater than 11 seconds. Then again bike handling skills could make up of that.
7.) Yes shorter cranks are generaly better for higher cadence spin and peek power. However pushing real hard at a cadence above 115 is going to snap up all your O2 befor you heart can even react. How long is your race???

I think that the short crank fad is over unless you are short, massive or you race is under 2 minutes.

If you are as proportional as the Leonardo Da Vinci's statue of David and do not already have a preference then take your hight in cm (example 170cm and convert that to 170mm) vola in the ballpark give or take about 2.5 mm, not so hard after all.

Read the following.

I have big thighs , I am short, and cannot move my seat any further forward. I would gladly trade my set of 170mm Miche cranks for a set of 165mm Miche cranks. For that matter I would trade my entire De Bernardy Thron 53cm bike in great condition for a 49cm to 51cm bike with 165 mm cranksets in great condition.

Any takers: nelson@de-young.com

DietChoke

I am a super big fan of having the same size cranks on everything. For me... that is 170's on everything.

Scott

tafi

Finally got to have a go on the boards yesterday at Dunc Gray. Was great fun. I have to say, though, that the crank length did crack me a bit. I ride 175s on my road bike and have found them to be the best for me (having ridden bikes with 170s and 172.5s before). To step back to 170s on one of the velodrome's spares threw me a bit more than I thought it would. It felt very strange pedalling in such small circles. Even though I was turning only 88in, it seemed to take more out of me at comfortable cruising speed. I know that no one really cruises in track racing.
Anyway, the upshot is that I now like track riding and I'd lik to do a bit more riding to get used to things a bit more. I just don't know if I'd be able to get a frame which would have enough BB height for some 172.5s or 175s so I can feel more comfortable.

ed073

How tall are you? A track bike shouldn't need longer cranks than 170s unless it's a specialised pursuit machine.

tafi

I am 175cm tall but have an 86cm inseam. Why should the bike "need" a certain length? I would have thought that crank length should be determined by the individual.

ed073

anything longer than 170s and you'll struggle to accelerate fast enough when an attack goes. Especially as you get stronger and want to ride bigger gears.

tafi

If I want to ride bigger gears then surely I would need bit of extra leverage to get any acceleration at all. Physicaly I would have thought that the bigger your gear the longer you need to get up to speed, unless you can generate a greater torque which can be achieved through stronger legs or through longer cranks. Torque is reduced in shorter cranks and hence so must acceleration. That's my understanding through physics. We can agree to disagree on this point.
Aside from this. I just think that it would be a pain in the arse after doing all the road training on 175s (which I am most comfortable and fastest with) to have to readjust a couple of times a week to 170s. The weight of evidence and the experience of others seems to be that you try to keep your road and track cranks as close in length as possible. I know that people have run 175s or even 180s in pursuits, and I am pretty sure I would do the same. I just don't know how safe a set of 175s would be in a scratch or points event on the banking. Maybe I could limit myself to 172.5s
Im just waffling on now.....