I think the BB and crank are OK. It's a TA BB, and there is not much excess space between the chainrings and the seat stays. It all worked fine when I had the 42/49 combo that came on the bike. It's when I switched to the 30/46 ( and took the DR off the frame to paint). When I go to shift from low to high, the cage just jams the chain into the side of the 46 ring and binds. Could it be something as simple as I just have the DR too low down on the seattube?