Originally Posted by
Jeff Wills
Bullseye made custom cranks up to 225mm length, and I've heard of tests done with cranks as short as 110mm. As Old Bob said, testing shows that there's very little difference in power production among different length cranks.
Here's a good start on the "real" answers:
http://velonews.competitor.com/2011/...answers_178528
To take advantage of radically different length cranks, you'd have to have custom frame made to keep the pedals at the right height off the ground. FWIW: I'm 6-foot-4 and I'm quite comfortable spinning 175mm cranks.
Five foot nine and have a 33 inch riding inseam... I too prefer 175's which might be a function of my femur length in relation to total leg length.
we build custom bikes for extremely tall riders and for some of them who might have a 40 inch inseam, a 190mm crank makes sense when that is built into a custom frame that also accounts for unusual dimensions.