Hello my name is Dimitry and I have been riding for about a year. I have a VT 2 stock with the XTR chain (I messed up the old chain) I am also 240 lb but can do OK on the bike. My chain started to jump off from the front middle gear to all the way over the smallest gear to the frame. WHY? It only happens on climbs when I have to hummer up. It really screws me up to since on the ramps and bridges once I am on it if one cannot pedal half way through one has a problem. I wiped out pretty nasty few times like that. PLEASE HELP….