Tall bike chainline problem
Hey all, new to this forum, so I don't know if others have had similar problems before.
I have a real beater tall bike, and am having trouble with the chainline. The top frame is a little out of line with the bottom frame, I guess, and it's causing the cranks on both the drive side and left side to wear out. The bottom bracket is a square taper, and the holes in the cranks are wearing into circles, and as a result, have a lot of side-to-side play. Tightening the nuts holding the cranks on helps a bit, but the cranks are FUBAR.
I'm running it single speed, but I use a deraileur to maintain chain tension, which also seems to improve the horizontal chainline mismatch situation. I've tried setting the chain on different cogs, but it tends to jump back to its most natural seating.
I think if I could shift the chainrings on the top frame further out, I could get the line from the chainrings to the cog cluster straight. I think in order to do this, I would have to extend the square taper on the drive side of the BB. Can anyone think of a workaround for this problem?