I'm having an issue w/ my chain coming off. I can ride it all over town and not have a problem... or I can go take off and hit a bump or brake hard and it will come off. Today I had the clutch locked with the lock and got off the bike and the clutch activated and caused the chain to fly off and roll around off the sprocket. Shouldn't it just stall in that case? Would the idle being adjusted to high cause that to happen instead of it just stalling? I'm not sure what the deal is, I figured it would be an alignment issue, but it looks pretty straight, any ideas?