I posted awhile back that my SD had an issue with the front brakes pulsing. The rotors did not seem to be warped checking the runout, so I suspected it was just uneven brake pad material on the rotors. At first I sprayed them down with brake cleaner, which seemed to help slightly but the problem always came back after a few rides. Today I used a pack of scotch-brite pads and a bucket of soapy water, scuffed and scrubbed the rotors down really good. Then went out and bedded the brakes, pulsing is now gone.