I really do not understand the rear end on these bikes, so I have a dumb question. My rear end sags a lot. I had the shock rebuilt (it was leaking) but even after the rebuild (by a honda dealer) it continued to leak and the bike still sagged a lot. Also when I go off a jump, the bike wants to donkey on me every time. Do I need a new spring or is it a combination problem? BTW, I weigh 210lbs.