Originally Posted by
topflightpro
Going to follow up on what Hermes said. Four or five years ago, when I started track racing, I was running my F200 on 94. A few months ago at a training camp, we were doing our warm up on 96. Race gear depends on what track I am at and wind.
One difference between Hermes and I is that I run 170 cranks. I have long legs, and my fitter, who works with Hermes's fitter, was very happy with me on them.
I am 6’ tall with long arms 74” wing span and legs 34 inch inseam. ERO wanted me to try 155 cranks. It is all about aero and breathing. Shorter cranks in pursuit allow a greater hip angle and sometimes are faster. I use 172.5 on TT and road and quite frankly do not notice any difference going from 165 to 172.5. I will say that the shorter cranks are probably better for my back due to putting less stress on it in lower aero positions.
In the “old days”, pursuiters used long cranks and big gears spinning more slowly with the idea that more torque generated more speed. Today, we have tweaked that thinking with shorter cranks for better body position but back to big gears.