I can count on both hand how many times I've ran it that fast. (OK, maybe if I had four hands) I'm climbing and doing technical trails way more than anything. If I lived out West I'd be hauling ass like that more often, but there are usually trees, other people or a 1+ ton inanimate object that I would have to navigate around.You lose that much with a 13t? I seriously couldn't handle that. I have the 13t but never installed it.