Originally Posted by tobukog

I'm sorry. I'm currently running a 150mm and I'm loving them. This is one place where I disagree with Dr. Martin -- it's not just an aerodynamic / ftting gain. I'm hitting higher speeds near the end of my sprint, both in and out of the saddle. My foot velocity is actually a little slower than before, rpm a little higher, maximal torque a little higher (more than what's lost through foot velocity so it's not a wash).

So why did this occur? I can produce more torque in the saddle because the knee doesn't come up as high -- going from 165 to 150 allowed me to lower my knee by about 30mm at the top of the stroke. Out of the saddle, it didn't make that much of a difference but it was huge when you sit back down. At the end of a race, I used to spend an inordinate amount of time accelerating and maintaining out of the saddle. Now I can sit down and accelerate after the initial hit.