I think we’re talking apples and oranges and grapes. AL has no true fatigue limit and has a finite lifespan. Steel and Ti do not.
It’s not unreasonable to expect a well-built and well-maintained steel/Ti frame to last a “lifetime” under normal use cases.
What is normal use?
I’d argue that a steel bike that is designed for a spirited ride is potentially not going to last as longer under a spirited rider.
Use as intended depending on the design? I don’t think it’s a vague definition. This is why warranties typically contain clauses about this sort of thing. If you huck a 5-foot drop on your Tarmac, that isn’t normal use.
I’m not a materials engineer but there’s some fairly simple physics involved here. It’s extremely unlikely that a rider will subject a well-built steel or Ti frame to its fatigue limit if it’s ridden under its intended use.
it’s not simple, it’s simplified - fatigue limit is something you measure in a lab on uniform test coupons
Sure, it’s a baseline to reference and of course a bike will not have uniform construction. Though ideally a good frame design will minimize local stresses within conservative margins to avoid aberrations. Doesn’t matter the strength of the material if there’s a failure to account for stresses at welds and such. This would be a reason for a warranty claim.
Lifetime guarantees are one of those ‘everyone knows better’ marketing lies that only has teeth when it suits the manufacturer, and we basically have to accept that it’s an acceptable lie.
we call this turdly butts
I bought a serfas bike pump for $20 with a lifetime warranty in line 2006 and I definitely got my $20 worth
depends entirely on how turdly you want to make the buttways. A 7/4/7 wigglebiek frame most definitely has an expiration date on it. A surly with a light rider, maybe not.
Wouldn’t tensile strength of the tubeset also play a role?
All this for some wordplay
To be fair, it is the bike shop thread
I assure you all that your feelings won’t hold up against the fine print
Barely English in here sometimes.
This.
The sad truth that the “nicer” the bike the higher the chance of a failure.
Every time I ride my Kogswell, I’m all, “is this the ride where the frame crumples under me?”
That thing is the wiggliest of wigglers and it feel so goooood
my long haul trucker has been hit by at least 3 vehicles and still lives.
rip several forks.
bikes ain’t shit but hubs and tires
bikes ain’t shit but hubs and tires
oh no it’s only their choice to set up shop someplace with a “low cost of living” where there aren’t competitive wages, which then Lynskey tripled down on
true, i think ferg is the only one that has an english