there is data chart or link somewhere in these threads from some fatigue to failure tests these german scientists conduct. big name, custom, steel, lugged, tig welded, titanium, aluminum, and carbon fiber bikes were all in the test group. all of the steel bikes were pretty much the first to fail. a cannondale aluminum, a trek carbon fiber, and one other aluminum bike finished wih the highest marks. they stopped the test before these bikes failed at all. but it was a bunch of german scientists. what do they know about engineering? cheers.