I'm realy getting into this whole commuting thing (Used TREK 750 Multi-Track), and am interested in getting an old(er) road bike.... the problem, is I dont know what to look for.... I saw an old Schwinn (late 70's, early 80's by the looks of it) at a thrift store for $20 the other day... Didn't know if it was worth it, and passed.... I'd like to get something that is quality and is easy to get parts for (I'd like to tear it down and re-build it completly).... Any sudgestions on what to look for? What to stay away from? Brands? Things you think I should just know?