All my bikes have Shimano M515 SPDs and the only issue as such that I have is when I unclip one foot at lights, junctions etc., from fifty plus years of habit, it is ALWAYS the left foot that comes off. So this means that the left SPD will wear out faster that the right - at least in theory - ! I have tried right foot unclip, but the left foot habit is so ingrained, it's going to take a LOT of practise before I'd be fluid with it. And also I tend to push off right footed.
Obviously I can't swap pedals round, so can one buy single new pedals I wonder - ? At least M515s are double sided, so they take twice as long to wear out - !
Obviously I can't swap pedals round, so can one buy single new pedals I wonder - ? At least M515s are double sided, so they take twice as long to wear out - !