The SH56 cleats to me are death traps. Mild sprint will unclip without warning.... Pulling out of a pedal on a tough climb---it is always at the worst possible time---

After a couple of weeks getting used to sh51 as long as you don't go back and ride with toe clips and straps you probably will never have an issue.

My opinion any way.



Folding 406 vs 451 wheels