Yesterday on the way home from work on my 2010 fatboy lo, I heard a loud sound like breaking glass from under my bike, i did not see anything or feel anything. So I pulled over parked the bike to see if i could see any damage, bike looked ok. I then walked up and down that street 2 times looking for a broken bottle/glass to ease my mind, could not find any broken glass on the road. Went back to the bike took another walk around and rode home slow till a few miles away then cranked it up and let her rip and everything sounded fine. Today washed the bike checked her all out and did not notice anything unusual. So still nervous decided to do a brake test. Road the bike 1 mile using only the front brake. When I got home the front disc was cool and rear disc was cool to touch. So this time took off for 2 mile ride using both brakes and when i got home front disc was cool to touch and rear disc burned my fingers as it was extremely hot. When I look at the rear brakes and press the brake pedal i cannot see any movement it looks like the pads are resting on the disc and has always had a small amount of friction. So some questions If the pads somehow broke would they sound like breaking glass? If it was engine or transmission would it make that sound. Bike rode fine today on the test ride and sounds the same no problems shifting. I have 8700 miles and was going to wait till 10000 to have the next checkup but that sound really got me worried. Wife thinks I hit something and it ricocheted out of sight. Any suggestions would be helpful. Just a note Ive already once had to replace the whole rear braking system on the bike due to a factory defect as the brake pad pin was not installed properly and the brakes dropped down locking up my rear tire on my first day riding the bike. Thanks!