Firstly, there was a typo in my last post. "The velodrome is out of TOWN" (not time
). Edited.
For some reasons, I thought is rather more or less secret thing. Especially for sprinters, due to tactics etc. I remember an interview with Fortsemann who said that elites don't talk about ratio and try to keep it as hidden as possible. He didn't even give an answer about the ratio he uses for that reason.
I guess calculating from a video can be not accurate. +/- 1 teeth even on chain ring makes a difference.