So the other day I picked up a new chain to replace the older, abused one on my commuter bike, a mid-80's Univega Gran Premio with Shimano 600 SIS drivetrain and D/T shifters. Ever since installing it I've had a problem with phantom shifting. I'm fairly good at tuning a R/D and fidgeted back and forth wondering why it was being so stubborn before finally putting it on the stand tonight and doing some work.
After replacing the small piece of cable housing with a spare piece of new stuff I had, I again checked my "master pin" for tightness and went on to check the hangers alignment. I pulled the wheel off and removed the R/D and immediately noticed a big crack just in front of the dropout. I immediately was both grateful and disappointed at the same time. "Thank goodness I had the R/D problems before this thing broke off" as well as "How am I going to fix this thing?"
So I'm posting some pictures for you guys to get an idea of a safe way of addressing this. I work fairly close to a great machinist and if it's safe to weld I'd trust that he'd do as good a job as any, but I'd like to know if there are any other options short of throwing the frame away. This bike belonged to my late uncle who died years ago from cancer and it's become my main mode of transportation to work and back. I've upgraded it along the way and one of the few remaining pieces is the frame. So it does carry some sentimental value.