ive never had a problem, i mean if you weigh anything over 160 pounds you shouldnt even really be considering alum crank arms on a bmx, i think that was the big failure they had is people just not knowing what equipment they needed, the original black widows where intended for race use not the jumping and what not they ended up being used for ive always liked them, for their performance and looks. I mean you throw any shimano crankset onto a bmx and start jumping with them and they will snap all over the place, especially the hollowtech ones