Originally Posted by
taras0000
Carleton's quote related to the ~120rpm range. I'm pretty sure that as the RPMs go up, the differences become magnified. For someone who's larger than the average bear, I'm pretty sure this would have an effect as well, although my guess is that it would magnify even more for someone who is short and revving at high RPMs.
You are right, but the gains don't diverge from the 2rpm for each 2.5mm until you get into huge numbers (like over 300 rpm).
It stays pretty consistent up to 150rpm:
165mm @ 150rpm
167.5mm @ 148rpm
170mm @ 146rpm
172.5mm @ 143.5rpm
175mm @ 142rpm
Are all 2.59 or 2.60 m/s tangential velocity.
So, the differences as you gain 2.5mm crank length were:
-2rpm
-2rpm
-2.5rpm
-1.5rpm
Even up to 200rpm, the differences were:
-2rpm
-2rpm
-3rpm
-2rpm
(all are around 3.48 m/s)
If I get properly caffeinated, I'll calculate how much the torque difference is between cranks lengths 165mm - 175mm to hold a given speed...taking into account the angles of the pedal stroke that are actually producing power (not the dead spot parts). As the angle changes, the calculation changes as it's the sine of the angle multiplied by the crank length.
Over caffeinated and I'll do it in Watts
