Seventeen years, steel. Aluminum ages way faster and just snaps. Carbon fails without any warning, too—no plastic deformation, no signs, nothing. Those fork welds are particularly sensitive. Maybe they should start using old railroad methods and just tap the frame occasionally to listen. A section with a crack should sound dull. Of course, X-ray and ultrasound inspections aren't exactly something you can do on your own.
... have you checked for corrosion yet? From what I can tell, it’s the tube running through the frame that snapped... maybe you could try to wedge something in there to fix it, or just—get a new fork...
Exactly. That’s why aluminum frames usually come with a five-year warranty, while steel ones (the real deal, Reynolds tubing and such) often carry lifetime guarantees...
There's also a massive difference in aluminum alloys. For instance, the 7000 series starts out incredibly stiff, but it gets brittle and sensitive over time. Meanwhile, the 6000 series is softer, which makes it a bit more flexible and durable... I wonder what the 5000 series was like; they don't really use it much anymore...
By the way, someone mentioned that a good, proper weld (regardless of the method) can actually end up being stronger than the base metal itself. Is there still a place like Lincoln Electric out there somewhere where you could get an ultrasonic test done?
I once had a frame split right under my seat—though that was because some previous owner had secretly welded it, so it actually cracked right at the weld site. Even on my new, high-end, triple-butted, hydro-formed, PM-coated masterpiece, I hear this vaguely unsettling creaking. I don't really notice it, though... but if I do, I'm terrified... 😬
