Hi all. I'm revisiting this question because i've been having more problems with this lately. It's not that it bogs down so much but if i'm really grinding hard on some steel, the belt wants to move on me. Sometimes it "pops" off to one side of the drive wheel's bump even. It's not yet flown right off but it does like to move around. I use a gas shock from a car hatchback for tension but it's only rated at about 30 lbs. Do i need something stronger? Or am I just pushing things too hard. I don't really have a feel for how much tension the belt should be under.