[dmitrynts]

Is there a difference in strength and / or a difference in the suitability of the alloy for its use in a men gane ?


Richard

[slarceSelia]

I can answer the alloy question. Steel and titanium alloys are famous because they are different than every other alloy out there.

Usually, if you stress a metal, even if it returns to its original shape, it is weakened. According to the theory, every metal (except steel and titanium alloys) does this, regardless of the amount of stress. The logical conclusion is that if you took an aluminum bike and sat on it (without riding it) enough times, eventually it would fail (crack). Even dropping a feather on it would do it. It follows a standard exponential curve (number of times stressed on bottom vs amount of stress on the side) so that number will be impossibly high, but the theory says that there will be some number associated with any level of stress. (The math phrase is that the curve asymtotically approaches 0 - the curve gets closer but will never actually cross 0.)

Steel and Titanium are special, because instead of asymtotically approaching 0 they asymtotically approach some threshold greater than 0. So steel and titanium can, theoretically again, be subjected to an infinite number of stressing below that threshold and not fail. Thus, steel and titanium can be guaranteed not to break if not stressed outside of their limit.

The exact makeup of the alloys dictates the stress threshold. Titanium alloys, while more expensive and harder to work with than steel, are lighter for any given stress threshold, which is why titanium is appearing in many sports (there are other reasons associated with availability, but I'm not going into those here.) Titanium is less stiff that steel though, which changes its feel in applications like cycling, but that should not be an issue in a men gane.

That said, a titanium men gane should be lighter and should last as long as steel. An aluminum alloy should be lighter (and cheaper, probably) than either, but at some point is going to get cracks - it might take 5 years, it might take 50 but if you keep using it, it is guaranteed to happen. I know MTB racers who have to retire two aluminum bikes a season because of stress cracks. And I know people with the same bikes that lasted 10 years. It's all in how hard you use it.