I bought a bike that hadn't been ridden in almost a year. (previious owner crashed it) The chain has rust on it. Can I rehab it back to life or should I just replace it? It still seems to move freely.

 

Mmm, give it a clean with kerosene, lube it & see if any of the links are not binding, check to see that none of the "O" rings have perished (your biggest concern). Then check if it needs adjustment & check the wear indicator to see how much life may be left in it. In the short term it may be quite ok, but I'd start putting some money away toward a new one.

 

i agree, take it off if ya can, clean and give it bath in oil overnight and let it drip for a day of too- but for a vital part in making your bike move, a new chain wouldnt hurt. They say chain and sprokets should be replaced together because they wear to echother, but whatever ya wanna do i guess- just my thoughts.