Google is your friend. The electro forged Schwinns are likely the most common vintage bikes out there. There is really more info out there than you will be able to read in a lifetime.
+ 1 Items should not be replaced just because they are old. The old heavy Schwinns were built out of some really durable (but heavy) parts.
Major issues with this bike: Did I mention it was heavy? Next biggest issue is the steel rims, like any steel rims, they are heavy, tend to get rusty, and don't stop (particularly when wet). Replacement with alloy wheels will make riding much more enjoyable. The third biggest issue is that Schwinn used some odd sized parts, particularly the stem, seat post and the crank. The stock ones do last a long time.
Last edited by wrk101; 08-23-09 at 11:54 AM.