Hrm. I know my left leg's probably a couple cms thinner than my right leg. Least it usually is if I measure. I used to do gymnastics and would perpetually sprain my left ankle when young - and I still sprain that ankle at the drop of a hat.

So I overcompensate for not trusting my left ankle by making my right ankle/leg do more. Which means at the end of a hiking trip or something like that - my right ankle or leg is killing 'cause I've initiated every jump with that leg or any tricky section of the trail. My right ankle/foot seems to do more when skiing as well.

I haven't literally measured whether the legs are different lengths. But I think probably I'm more likely to keep my left ankle at neutral or comfortable positions when biking, and then overcompensate with my right side if I have to - I don't think I pedal harder with my right foot, but I'll pay attention next time.

Either way, my foot seems happy for now, so I won't use insoles, I won't put my seat up too high, and I'll see an orthopaedist if the pain comes back.