To add to the last comment by airborneSGT, I watched a fellow tumble a 50cc Edge and bent the wing tube so bad it couldn't be removed without cutting it off on one end. There was nothing wrong with that tube beforehand so as mentioned previously it's VERY hard on the airframe. He was lucky to get that Edge back on the ground and the wings had more dihedral afterwards than any trainer I've seen, kinda like daveopam's cabane tearing out of the top wing. Tumble's can be pretty violent and destructive.