I dont know man, I wheel the hammers and the rubicon for the most part, I dont take the stupid lines, but it happens. Maybe its just the luck of the draw.

Man i take the stupid lines all day long and have not tore a sidewall or anything with my 37" MTRs.  HA HA I think they rock(old style anyway). As a matter of fact i was pushing pretty good on the rear against some gnarly sharp rocks and never had a problem this Monday! Same trail last year, same thing but i was into it harder and ya could see the tire pushed away from the wheel. Wasn't even loseing air out the bead yet! I was a bit sceeered that time but they held up! Also ya can see the rock in that vid that did it!  I don't run beedlocks and it looks like that jeep was pretty aired down and the sidewall ran right on the edge of that rock that is there. Its not a big rock but big enough when your aired so low and ya get the weight of the jeep and 5lbs of air the tire tends to fold and not roll. So if it folds on a sharp rock it will tear it. Am i making any sense??? Just my therory cause i run at 12 psi and no lower than 10 psi without beedlocks and they work great!!