I have skated Ace in 33, 44, 55 and 66 and never bent them. I mostly skate the 44 or 55's, I ground one set to the axle on both trucks, and about to hit axle on another pair. I have yet to bend them, the worst I have had happen is the pivot cup blew out (easy to replace) and the axle slipped after a year of skating.
I don't know how people keep bending them, it baffles me as I am not a skinny dude and I do a lot of slappies, so you would think I would have bent at least one pair in the 6 years I have been riding them.