Quote:
Originally Posted by CurtEgerer
Fignon on a Bianchi. It's disturbing 
Crank Arm Length: About 2 years ago, I had a revelation when I borrowed one of my brother's bikes and rode it regularly. I couldn't quite figure out why it was the best bike I ever rode in terms of power output, acceleration (or AXceleration if you're Bob Roll), and smooth spinning. Finally traced it down to a 165mm crank! I've since switched all my bikes to 165mm. When I ride a 170mm, it is immediately noticeable. I have about a 29" inseam. There's been lots written and a couple of good methods for determining ideal crank arm length. Mine works out to 163.
As an engineer, it makes no sense to me that the cranks on 95% of all bikes are either 170mm or 175mm (less than 1/4 inch variance), yet inseam lengths can easily vary by 8 inches. It's based simply on production costs and compromise. |
I was told years ago its about power, so everyone went to a 53 ring. Well, so did I and the 172.5 crank. I am sure it make no difference, by my butt dyno anyway. Never tried 165, but trackies like it. I betone can spin like crazy on them. Now I am back to spinning a little more, so I am sticking to 170 cranks. One of the guys that ride with us is 6'4". I loan him my 170 mm crank and he said he felt no difference and still motor like hell on the flats.