[jefflyng]

I'm looking to use a compact chainset instead of my current 52/39. Should I use the same crankarm length on the compact as my current chainset (170mm)?
Presume they will have to be same length from the axle to the pedal.
All this starting to look a bit obvious but appreciate your confirmations or otherwise.
Thanks.

 

[Becky]

Yep, I would.

 

[cyclust]

Yes, as long as you are happy with your current crankarm length. Switching to a compact doesn't change anything other than lowering your gear ratio a bit.

 

[Mr. Versatile]

Like cyclust said, the only thing that changes are the chain rings. The crank arms are the same.