Originally Posted by
sdmc530
what is the group set? Might be a really cheap replacement....Ebay has a ton of stuff like that pretty reasonable. Be warned though if the rear is that bad there is probably more to fix/replace/repair than meets the eye.
Its a wear part in all truth but it can be a sigh of maintenance issues or lack of care.
Echo on more to fix with a screwed up rear derailleur. The mode of failure will tell you where to look. Maybe it was dumped into the spokes (check spokes for nicks, loose spokes, out of true wheel) maybe it was trashed in a crash (hanger out of alignment, crash damage in other areas, derailleur mounting threads damaged).