Originally Posted by Fasteryoufool

This is why for all practical purposes, bike frames made from aluminum have a VERY marginal weight advantage over steel. In order to make it strong enough so as to not deflect and fatigue, it has to be nearly as heavy as the steel component (assuming they're of similar quality) would be.

You CAN make an aluminum frame that won't break from fatigue, but it'll be nearly as heavy as a comparable steel frame, and from a frame standpoint, less comfortable to ride. That can be mitigated with wheel/tire choice, seatpost choice, etc., but in my not-so-humble opinion, a large steel frame that flexes just gives a better ride.