feedtherat wrote:
thanks Sam, 'preciate it.
while you are online, i remember reading about your experimentation with short cranks a few years ago.
above (in this thread) you mention 165 -175 being optimum for you now. that's still a 10mm spread though. i wondered why? are you still experimenting (fine tuning)?
I have been experimenting with lengths ranging from 130-180.
In short my findings - which are very personal:
- any length between 155-175 is fine for me (in terms of long term power output)
- shorter than 155 is a bit hard on steep hills (unless I adjust gearing which I didn't)
- 130-155 still is ok in terms of power output but it affected my flexibility (I should say inflexibility) and some tendons in the groin area from pulling to actively during races
Some sidenotes:
- I have very tall legs (95cm inseam), so for me, a 175 crank feels not too long
- shortening cranks means increasing saddle height which is already high in my 175 setting. This poses problems with TT frame geometries and seatposts that usualy can't accomodate this height
- my steep position with short cranks (130) made the transition from bike to run tough for me (my core muscles cramped up) in the races I used short cranks.
- there seems to be no aerodynamic benefit riding short cranks (we thought there was)
My preference:
- I think I would prefer 160 but only if a frame had a BB drop of 85mm instead of 70mm. Such frames don't exist.
Conclusion:
- It is interesting to experiment with different cranklengths
- Better a crank a bit too short than too long
- You can change cranklength, seat height, handlebar setup but unfortunately, the position of the bottom brancket is fixed and I would prefer that to be lower when riding shorter cranks.
As I said, these are my personal experiences and I am sure there are lots of people that don't agree or have experienced other setups that work better for them. You have to find a balance between position, aerodynamics and power output and the determination of your optimum cranklength is for sure an important factor.
Hope this helps :-)
Sam
samgyde.com