How do I know which bikes are worth working on and/or owning? The local thrift stores have a continous supply of bikes, but I'm not sure what to look for. See a lot of Schwinns, Peugeots, Magnas ... but don't know which are "disposable" and which are worth investing in. In most cases, test riding is out of the question (no space, flat tires, etc.) Has anyone composed a guide or list? Or can suggest a good book about various bike models?