Interesting, the chainline didn't look obviously off either. I've played around with it a bit though and will test tonight or some time in the next couple of days.
I wonder then if it is a mis manufactured chainring. I recently swapped in a new crank set and a new chainring (old chainring was cracked at the drivepin hole, old cranks a little bent). I wonder if it could have something to do with those swaps then.
The new cranks were 24 thread Ashtabula type-- I'd always followed the wisdom that these were all pretty much the same (aside from 28 thread Schwinn type). It fit in there fine and turned freely though it seemed.
I also put in a new chainring, I wonder if it is out of round or is mis-manufactured. I've never heard of this, but I suppose it's possible.
I have ordered a different chain-- one more similar to the original one. What I put on there was a 1/8 inch, 1/2 inch pitch Sachs SRAM. I figured it was the same as a standard old style chain. I suppose for $5 I could find out though and buy a new chain that is more similar to the original.
The only majorly concerning thing I heard is one guy I asked mentioned it could be a cracked or bent axle. I'm not sure how or when I would have done that (I've babied this thing), but how hard is it to bend a solid axle like that?
