Took my rear wheel off myself today to get my BT-016s installed (last two times I had a shop R&R the wheels to mount the tires). Found grooves cut/worn/molded (I'm not sure which) in the surfaces which face the sprocket mounting plate of many of the cush drive segments. I can't imagine how they got there since there's really only one way to install the sprocket mount. Take a look at the photos. Should I replace the cush drive when I re-mount the wheel?