Originally Posted by Iride01

Wait till you know they are a issue for you. I already had some previous experience that made it reasonable for me to change them out at the get go. A previous bike I put longer cranks on and couldn't get use to them. And that was in my early 50's. All my previous bikes were low cost Schwinn's from the vintage years with Ashtabula cranks that tend to be 165mm or less. So my knees were use to that. And there are other more common causes for knee pain on a bike than crank length. So investigate the other causes first before jumping to the somewhat expensive solution that may not actually solve your pain.

I'm actually again toying with the idea of putting those longer cranks back on an seeing for sure that there were or weren't the issue I felt they were.

Surly does size their bikes a tad differently than some others....