Crank Length (Sprinters)

Sold!
I am going to put the 160mm Profile cranks onto to my Dahon Mu..

I read somwhere a bike Mfgr in England calculated 149 MM is the optimum crank length for power vs efficiency, which matches up with that graph. Back in the old days (70s-80s, when East Germany dominated the match sprints) it appeared those guys were using quite short cranks. I used 165s on our track in Minneapolis. The slowest speed they told us we could go was 15 mph before you clip a pedal. If you clip a pedal, that raises the back wheel and you go down. With my high BB and 165s I never came close. As a match sprinter, you avoid slow speeds in the corners anyways and try to use the straighaways to play chess with your oponent. Our track was 43 degrees in the corners and 11 on the straights. Some 250 M tracks are 45 and I think the shorter tracks even steeper. I'm interested, however, in what kind of crank arm lengths sprinters are using these days because the 200 M TT WR has droped to under 9.2 or so. That's a huge improvemement that can't be explained by high tech bikes. I'm thinking the guys that can put out 2500 watts on their bikes are figuring out ways to leverage that power more efficiently (pun intended). I don't think they are trying to spin 160+ rpms anymore like we tried to do back in the day. I just wonder what kind of crank arms they are using to harness that big power.

I don't think they are trying to spin 160+ rpms anymore like we tried to do back in the day.

I think you’re right, the gearing used has increased massively instead.

I heard some sprinters at work saying recently that the gearing Chris Hoy was using when he won all his Olympic medals would now be considered a warm up gear.

I think it’s mostly the tt riders that have been experimenting with crank length, trying out both longer (to make gains on the start) and more recently shorter, but I’ve not really seen any of that from the sprinters.