Ah yes... Thrusters Revenge. They're hiten steel. Single speeds are more trust worthy than almost any geared walmart bike. But most of it depends on who built them. Like about all walmart bikes, the wheels are the highest risk. I'd certainly build one of those up. I almost got a Thruster out a dumpster once, but somebody beat me to it. Wheels, bottom brakets, and brake calipers can always be swapped out, and is pretty much all there is to those bikes.