OK somehow my earlier post didn't show up. If the tread bumps rub off your pedals, it's because they're crappy pedals. That's what happened to mine, and I was using normal sneakers. You can get inexpensive METAL platforms for less than $20 I think, or you can do what I did and get Performance Campus pedals, decent platforms on one side, clipless on the other. Then you can try clipless whenever you feel like it and ride platforms whenever you feel like it too.