Crank length??

Mudge wrote:any thoughts on using longer cranks on a gravel bike, vs road bike?

Specifically, I’m comfortable with either 170s or 172.5s on my road bike, and use 165s on my TT bike.  I don’t ride mtb anymore, but never had issues with 175s when I did. 

Without buying anything new, I have choices of either 170 or 175 for a gravel build I’m putting together. 

Thoughts/suggestions 

I read an interesting article that basically said your optimum muscular contraction speed is fixed, so by going from longer to shorter cranks, you would need to increase the RPM to have the same muscular contraction speed.  In other words, long cranks are for slower rpm, short for higher rpm.

Makes sense.  My tandem and mountain bikes (both of which need lots of torque) have 175mm arms, while my track bike is at 165mm (and I’m pulling hard up to 150rpm).   My gravel bike is in the middle at 170.

smoothmoose wrote:Also depends on your BB drop, if you plan to run 650b, and how often will you be riding offroad with chunky stuff around.

Too avoid pedal strikes, go with the shorter cranks.  Since you are comfortable with 170mm, I would just go with it.