Hey There,
I just got this reply on one of my other threads (about seat posts).. what do you guys think.. If it the info is correct that would suggest that Alu Swifts will not last particularly long... I guess there is always a trade off, being able to ride a light Alu frame for say a decade might be worthwhile. For others lugging around some extra kilos but having your frame last for up to 30 or more years may be the ticket. I am not exactly sure in which category i myself fall.
"Just a more general word about alloy vs. steel frames: Aluminum and steel have very different fatigue characteristics. When talking in terms of flex cycles, aluminum fatigues many times sooner that steel. Even minor flexing can contribute to metal fatigue which will over time lead to the failure of aluminum components. It is for this reason that airplanes are "retired" after a given number of hours in the air. The odds of a structural failure grow and grow. So, with regards to alloy frames and seat posts, it should be considered that they have a finite lifespan. If ridden long enough, even without abuse, they will fail. Steel has a lifespan too, of course, but it is probably longer than the lifespan of the rider."