Track Crank Length

VeloFlash

On the velodrome crank length would only be a problem when you are going slow on the banking. That does not happen in tt, keirin, derny, scratch, elimination, pursuit or points races. Only in sprint, more so match than derby, and remotely in madison.

Crank length has been the matter of some debate for years. Results of testing I saw were that a rider was most efficient in the crank length to which the body had adapted. Changing lengths had an negative impact on efficiency. It would be obvious that a change of length altered joint angles sufficiently to bring muscles into play differently.

I used 175s on road & 170s on track. I use only 175s now for both, well at least 5 years now, and have benefited at the track.

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VF

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

EoinC

Being a cheap arse (and now living an ocean away from the nearest velodrome), I ride my track bike on the road. It has 165 cranks and feels like riding a bloody circus bike, particularly when trying to kick up a hill. I'd like to put some 170+ cranks on there, but it really isn't a big enough problem to justify throwing money at.
The only time my pedals touch the road is when I'm already on my way down anyway.

miss claire

On my first track bike i had 170mm cranks but after it was stolen my next one had 165mm cranks and i never got used to them if i ride the track again i will invest in will go back to 170mm,s

rooman

I use:

Track Racing & Track Training: 165mm Superbe Pro cranks with Toe Clips and Duegi Shoes ( rock solid, high cadence performance) from (79in rollout to 104in rollout)
Road Training Bike : 172.5mm Campagnolo Daytona Alloy Cranks & Look ARC Clipless pedals ( bomb proof) on a 9 speed gearset
Road Racing & TT : 175 mm Campagnolo Chorus & Dura Ace Clipless Floating ( flight and might) on a 10 speed gearset

I am 189cm tall and have high femur over tibia ratio .....

bottom line...on DISC with banking of 42Degrees 165s are superb to permit slower tactics and sharp turns for high acceleration sprints down the bank and ultra smooth high cadence above 150rpm

on the road for training the mid 172mm cranks make me work out and , give me smooth high cadence training (110-120rpm) and very smooth recovery (100rpm) plus the heavier bike/tougher load gives me a stronger prep for races.

In road races and TT the 175s deliver great leverage and increase wattage, at modest cadence as at high cadence over 120rpm my long legs start to bounce me around , hence from 100 to 120 , the 175s optimise my output and save me going into the red.

This mix of cranks works for me...guess it depends on your physiology and needs.....

good luck

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Nyrie

165 record pista on the street

one is 2004 and the other is 1974

one is on a paramount and the other is on a keirin frame which will soon be swapped out for NJS approved cranks.

Clipless atacs or mks clips.

no pedal strike ever.

barely any overlap

Fixey

no one seems to have covered the obvious....(obvious to me anyhow)
the shorter the crank the less actual distance your leg moves per rotation!
I do not believe that hieght will have any baring on crank length at all (all things being equal)

rickt

There is mounting evidence to suggest that thigh length and crank length are linked/tied together. There appears to be an optimum range of motion (arc) for each individual. Imagine a person with a thigh length (using "fit kit" methods) of 355mm (me), to get over 175mm cranks my thigh would have to move through an arc of 59.07deg (simplifying to exclude lower leg movements). "Joe Average" with a thigh of 420mm would only have an arc of 49.25deg. It is a fact that the person with the shorter leg can have muscle attachments the same distance from the pivot point as the person with the longer legs. Therefore poor old short a___ has to contend with the extra energy expended through the need for a greater amount of muscle contraction. It should also be noted that even though you change the leverage by changing crank length, the effects on acceleration shouldn't change by the same percentage. eg, 170mm cranks are 3.03% longer than 165mm cranks. I don't have any figures for this next part, but remember that your legs get stronger the closer they get to straight, at the bottom of the stroke the knee bend will be the same on both cranks. But at the top of the stroke, there will be less knee bend with the shorter cranks, therefore your mechanical advantage on the longer cranks will be less than the 3.03% gained by the difference in crank length.
I have an unusually short thigh, so after having raced for 27 years on 165mm cranks and being extremely quick off the mark but with pretty poor top end speed, I decided to get 160mm cranks specially made (at 35 years old). I am still, at 44, doing the same times for the flying 200 as I was when I was a MUCH fitter 25 year old on 165mm cranks. I am even pulling out PB's for a standing 500. I really should have done weightlifting as a sport (from a biomechanical perspective) but enjoyed cycling FAR FAR better.

VeloFlash

In this study it is proved, submaximally, there is no additional metabolic cost as a result of increased or decreased crank lengths:

http://jap.physiology.org/cgi/content/full/93/3/823

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VF

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

WarrenG

In that study all the efforts were measured while in the saddle/seated and track racing includes many _maximal_ efforts.

As some experienced people have already mentioned here, 5-10mm can make some useful differences for the intended races.

VeloFlash

As there are no studies at maximal or supra maximal efforts there are no references to support a contrary view that there exists a greater metabolic demand at maximal plus efforts by using longer cranks. If there is no differentiation in demand at sub maximal efforts why cannot it be extrapolated to higher efforts?

I have a n=1 support that changing crank lengths up by 5mm to your normal road length will improve track times. My times against the clock at the track improved or was it from the placebo effect or different training?

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VF

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

WarrenG

No studies? Maybe you don't ask the right people or know how to conduct your own objective "studies". Out of the saddle needs vs. seated? Sudden changes in speed and/or cadences? Means to reach maximal efforts vs. sub-maximal? Don't learn for yourself-trust only Pubmed for all your training.