Originally Posted by
BobbyG
I had that problem on my old 12-speed and it turned out to be a broken axel. It performed fine, but deflected a lot under heavy load. I'd check for that.
I had that exact same problem when I had a broken axle. That's how I learned it was broken, because when I'd put pressure on the pedals the tire would rub on the left chain stay & seat stay. When I pulled the rear wheel off to see why it was doing that, that's when I learned the axle was broken.