If you ride SS first and then switch to Fixed... be careful. lol. I don't know if I'm dumb but my SS muscle memory was insane. I rode SS for 2 1/2 years and then switched to fixed. First day I rode fixed, I was pedaling super fast on this long and straight flat road. Once I got my speed I went to relax and coast because I had forgotten I was fixed. Wam, my legs went flying every which way and I was skidding across the asphalt until i was abruptly stopped by a parked car. My worst fall ever. Steel frame was bent. Had road rash on my arm, leg, and side. The car was all dented where I hit. Anyways, I limped home feeling dumber than dumb.

Needless to say, every day I rode after that, I kept repeating in my head "I'm fixed, I'm fixed", so I would remember to keep pedaling.

Muscle memory is a crazy thing. I've been riding fixed now for a little over a year and all is good. Muscle memory is now used to constant pedaling. In fact, it is super weird and awkward when I ride a SS now.