Originally Posted by
Robbo_Rider
Is there a key to prolonging the longevity of an aluminum frame? Is it as simple as washing and cleaning the frame on a regular basis? Personally, I was thinking that 6 year mark might be grossly understated for full suspension bike since the shocks should absorb a signification portion of stress? I mean, that's their purpose, correct?
OP had some good questions. Not all of them are addressed by the Usenet-vintage "aluminum has a fatigue life" canard.
Taking care of things definitely helps. But think more armor than cleaning. A really good thing to do on a mountain bike is cover up the right chainstay, to protect it from the bouncing chain, and use frame protector decals. Mostly mountain bikes are made of thick enough tubing that a gouge can't start a crack but you can choose not to risk it.
The purpose of rear suspension is to keep the bike under control. It allows you to ride faster on worse trail. I don't think anyone would reasonably argue that it makes a bike more durable. It creates more locations where forces are transferred and the leverage is increased and adds moving parts.