Re: My third wreck due to "issues" with bike
Glad you are OK and I like the quarter idea, maybe even a 1/2 dollar ;-}
It sounds to me like the bolt came out seizing your motor first, and THEN your tensioner broke because of the sheer direct force of your back wheel trying to turn the chain. I can't see it going the other way.
If you had a full head of steam that would be like a whack straight down on the tensioner wheel with a sledge hammer.
Are you running #41 chain, or the stock #415?
415 should have broke but I can see 41 not giving first.
I have no problem with stock bearing tensioners and put them on most every build for customer tuning convenience, the trick is to get the chain as close to perfect first, and then mount the tensioner to leave the most adjustment up.
Regardless of what you do with chain tension I suggest:
Pull off your back wheel and check everything is still true and no damage, I can see the sprocket turning until it hit a spoke and who knows what else after that like it's alignment and even the wheel trueness.
Check your motor drive sprocket, a jolt like that could have easily sheered the woodruff key.
And most importantly check your engine mounts! I have seen similar abrupt engine sprocket stops that have ripped the engine almost all the way out of the frame and in another case actually breaking the frame.
I have pics somewhere, anyway the simple rule of thumb is if you can move your engine AT ALL holding the top bar with one hand and the head with the other, pushing back and forth AS HARD AS YOU CAN, it is a fail.
Best of luck on the rebuild and I hope that helped.