I had two bow rollers shipped to me. One of them was fine but the other was defective. Somehow it was molded with the shaft hole diagonally positioned and not on center. (If I wasn't in a pinch and the nearest West Marine wasn't an hour away at the time, I would have just replaced it.) It was so out of wack, that I had to put it on a lathe and drill an 3/4" hole trough, and turn two bushings that were press fit for both ends.