shelf life for aluminum frames?
 

It was brought to my attention that aluminum frames have a shelf life. Anybody know about this? I'm on a 20 year old aluminum frame, been riding aluminum frames for the last 15 years. And I have never considered this "shelf life" thing.
Fill me in please.

I'm guessing that's crap. And if it's not, I wouldn't recommend flying if 15 years is the limit.

Metals fatigue. This is why airplanes have mechanics and repair cycles. As for the mtbf, I don't know and it depends on how hard the metal is pushed.

Yeah, but they don't replace the entire airframe. Which is aluminum, and goes through stresses you won't be putting on a bike.

I can't speak to the reliability of any frame in particular, but I don't think aluminum non-moving parts "expire".

Metals do fatigue, and the long-term performance of aluminum is such that it will eventually break if it is used... "eventually" meaning 5 or 10 or 20 or 50 or 100 years of use. But this only applies if the metal is stressed. "Shelf Life" generally refers to a product that can only be stored (not used) for a certain time before it is no longer useful... I do not believe aluminum frames have a finite "shelf life"

Any bicycle frame made of any material, if used long enough will fail.

As with any frame, when you clean it, look for signs of problems like small cracks, bubbles in the paint, or anything else unusual... I understand these are the same signs they look for on airplanes when performing maintenance.

If you don't see anything unusual, there are still no guarantees, as even brand new frames (of all materials) will rarely fail, but you have done all that you can to ensure that you are riding a safe frame.

Shelf life? Probably about the same as a B-52.

Aluminum fatigues, steel may or may not fatigue, carbon fiber breaks. In each case, it's a design issue of dealing with the material, not just some material flaw. I sure wouldn't worry about a "shelf life".

Bare aluminum will develop little pockmarks of corrosion, just like bare steel will rust, and maybe somebody is deducing a shelf life from the bare material or something flaky like that. But that's an issue of how long it'll loook pretty enough to sell, not related to be useable.

Bit of trivia: I was scanning a book at the library on the Tour de France. It showed one guy fixing a flat, and mentioned that he had been thrown out of the TdeF two years in a row by broken forks. That was back in the 1920's.

I am sure the halflife of Aluminum though it may be less than steel is not affected in a humans lifespan to make a difference. Besides that the bike is covered in paint and is not expose to oxygen. If it were, unlike steel bikes that rust, aluminum would be far less affected by it. Most likely that means that in a humans lifespan, aluminum is a better choice in metal deterioration. All of this is trumped with the fact that there are way to many variables to even put this to the test properly. Riders weight, riding style, conditions, terrain, maintainence, etc...

Shelf life no, fatigue life is what you should be aware.
Useful life span for an aluminum frame can range from 50+ years for a sturdy, overbuilt frame to 2 or less for a 2.5 lb. race frame that's ridden hard.
Design and execution of the construction and how it is used all come into play.

Can you back that up with any data?

I dont think we are comparing quality here. the OP strictly asks the difference in the metal. Like if you took the exact same frame made by the same person with the same care exactly the same way, just one is steel and one is aluminum? The only thing you would notice in a lifespan is how different you rode the thing.

The fact that you fall alot or hit a curb on multiple occasions in a bikes lifespan has WAY more to due with how long it is going to last. It is Easier to make a more durable HEAVY ass frame because it is cheap. But if aluminum and carbon and compsite were THAT bad to reduce it's lifespan to 5 years or less because it is light, there is no way that they would sell them like they do. Most likely, they probably would not be the primary selling frames in the world.

Half-life of an aluminum frame =

Time from new till it falls apart underneath you

DIVIDE BY TWO:thumb:

No algebra or calculus required, even the biggest fool can determine it.

(LIKE ME):roflmao2:

It won't be the aluminum as much as the quality of the construction.

LoL

+1 but why would the quality be different? You can not compare the two if there are not at least using the basic principles to the experiment. If the quality is not the same, the experiment is at "Need Input" status.

Johnny Five Alive!

That concern and my race bike's 800 dollar rims; one of the reasons I leave my Sunday bike for Sundays.... Besides weekday rides are often commute rides and I carry weighty stuff. During the week, steel is real.

Pretty sure my Le Tour will be there after the bombs are done going off, I know how you feel. I just like my Aluminum FCR too much not to ride it the most.

Cute but...

the more correct definition would be the time it would take half of all frames of a given manufacture date to disintegrate. So if you have 128 new frames on the shelf, after one half-life you'd still have 64 good ones, then after another half life you'd have 32... etc. So for any particular frame, there'd be a 50-50 chance of it decaying in one half life period.

...but that assumes that the probability of a frame failing at any moment is proportional to the number of the original batch still remaining at that moment. Radioactivity behaves this way (which is why the term "half-life" has crept into the popular vernacular. I suspect Diabloscott was slyly referring to this with his/her reference to "disintegrate" and "decaying".) So do some drugs (roughly, for a while) as the liver and kidneys metabolize and excrete them. Unless you know that the system obeys "first-order" kinetics, it is not meaningful to talk about a half-life.

A term that requires no assumptions about the system, just simple counting, is the "median" survival: the time by which the first half of the frames in the original batch will have failed. If quality control was really sloppy, but some frames were built very well, you could have half of them failing in the first year, but the ones that didn't fail might last nearly forever, i.e., you couldn't predict that half of the survivors would fail in the second year just because half of the originals failed in the first year. Conversely, if the factory produced mediocre frames of nearly constant quality, none might fail for, say, 5 years, then they would start failing all around the same time.

Does anyone actually know of an aluminum frame failure resulting from fatigue? Rule out crashes and neglect.

Anyone seen a "BEST IF USED BY 02/22/2049" label on a frame?

I have seen this many times. Frames just crack after some time - often years and years. I have seen it justr as much with ti and steel frames, though.

The failure, though, is often at a joint or lug where the manufactuing process has presumably weakened the material.

Bingo.

I know some lbs will use this idea to make more sales. if your frame or bike is 4 & plus years old they will tell you it do to stress of time and must be replace . by the way my cannondale is 14 yrs and at this point show none . my lbs even try to tell me at the time cannondale would buy it back if i buy a new bike. i believe the shop owner was giving me a line of bull at the time.