my buddy has a 2009 dragon 800 that somehow broke the rear shock off while just riding down the trail. I have heard of some other ones doing that. What causes them to shear the shock off and bend the shock arm at a 90 degree angle? ALSO, the track sounds like something is hanging up. It makes loud thumping noises when going anywhere from 0-60 but over 60 it smooths out. Going in reverse for more than 5 feet will bind up the track and it wont move. Any thoughts? Rolled it on its side to turn the track but cannot find anything hanging up