Originally Posted by
JiveTurkey
Change your chain once 12 links has stretched between 1/16" and 1/8" past 12":
http://sheldonbrown.com/chains.html#wear
A little rust on the chain isn't irreparable. I find Tri Flo gets rid of a lot of it. I'm sure others have better ideas.
Unless it's real bad there's no need to replace your chain. You'll be surprised at what a shot of Tri Flo or something similar followed by pulling your chain through a clean rag will do. Two or three minutes is all that it takes.