I was wondering if new 700c rear wheels are compatible on old 10 speed bikes. I am possibly going to buy a bike from a friend with a bad back wheel and swap in a 700c wheelset, that I think is from a multispeed Windsor. I am not 100% certain what it is right now, but I'll find out. I think the main concern are the gears and derailleur. I noticed that newer bike gears seem smaller and closer together compared to old bikes from the 80s.