Hahah thanks dude! yea its pretty much just an old tube and a bunch of zip ties nothing special, I took it off because it was rubbing on the frame. I would recommend just getting some chain tentioners to keep the chain tight it will keep the cranks from spinning so fast.

 That's what I have been doing, it works really well. Just though that you had some super custom crank stopper, and I was right. Its a custom as they get!

 about a week now, its such a sick bike!