Originally Posted by
KonAaron Snake
Quick question on aluminum and fatigue life...
I know that's absolutely true...aluminum will, at some point, fail with usage. CF also has a fatigue life as I recall. I know the air force learned that the hard way when planes with aluminum wings kept failing. My question is - is it a theoretical problem because the frames are over engineered and the point at which they fail long after we're dead? In other words - how many aluminum frames truly are failing due to fatigue life? How long does it take? My gut reaction is that, while they will fail, the point it happens is so far down the road as to be irrelevant in the real world.
Hi there KAS!
That's a fair question. The answer is usage dependent. The more the aluminum frame is ridden and the harder it's ridden, the closer it approaches its fail point. The aluminum frame is also subjected to the rider's weight. That too contributes to a shortened fatigue life. However, that's not the only negative factor about aluminum that should be considered. Aluminum has a very low yield strength or yield capacity. That means that in an accident, aluminum will prefer to break or snap, as opposed to bend or flex. It therefore, is not too impact-resistant. Also, while aluminum will suffer dents, fractures, and gouges, steel will only suffer nicks and scratches, upon most minor to medium impacts.
- Slim
