After riding about 400 miles this weekend, about 5 miles from the house I noticed a high pitch hum that sounded like it was coming from the rear of the bike. I touch ed the brakes, no change. It also had a sound wave like the "swoosh" the front brakes make. Reminded me of the squeel tractor trailer brakes make. Are my rotors glazed, pads shot, never heard of this??? It really annoyed me the last 5 miles home. Note. I did do a lot of mountain curve carvin, but there was more straight than curves, hills, etc.