Greg over the years I've pounded aluminum mountain bike frames no suspension and with partial or full and they held up great just as good as steel.The black bike in my avatar is aluminum, its my first bike I built in early 2011.
Hey, I'm new and just bought a Onyx 29" bike. I have no idea where to staty. But I want to put an engine on it. I'm about 160 my son is about 315Done a few with Alum. Frames. No Probs. Mount the motor secure being careful not to crush or distort the alum. My Daily is an Alum. Genesis Onyx 29". Very solid.