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Spot Ryve 115
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You need to re-think what you said there.
Guide me then, which source tell you otherwise.
Aerospace industry seems to have fatigue life of material figured. Aluminum parts have pretty low fatigue life so it usually design to not flex to minimize its fatigue cycle. Its strength degrade at quite a fair bit higher rate than steel and titanium, while carbon fiber can flex over and over without losing integrity (as long as you don't cross the line and destroy it).
You can also see example of ancient aluminum road stem completely break apart from fatigue after a decade of use. My 10 years old aluminum road frame is also no longer feel stiff. I guess micro cracks are all over the frame and weaken it significantly by now.
You won't notice this on carbon fiber that even design to flex (which, in theory, use up a lot of fatigue life), or only after a life time on titanium and steel frame.
 

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Magically Delicious
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Aluminum work hardens or commonly referred to to as strain hardening. ... To soften the metal, you would need to anneal the metal. Aluminum does not get softer, it hardens to the point of becoming brittle. But that service life will be far beyond you can subject it to.
 

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Magically Delicious
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Right. I guess the aluminum itself harden, but micro cracks it form from being more brittle make my old aluminum frame feel less stiff?
uh...nope. Even work hardening will increase stiffness in those areas subjected to 'micro-movements'. We might be getting a bit granular here though.

Making micro cracks assumptions might be just that...an assumption.

Easily validated.
 

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Spot Ryve 115
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Yeah, I give up.
For whatever reason my old aluminum frame get dramatically softer at the bottom bracket during the late stage of its life. Since it's no longer ride like new (or even a few years back) I don't trust it anymore and retire it.
Maybe a one off that contradict the normality of aluminum frame get harden and brittle with use.
 

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And also have virtually infinite fatigue life. Unlike Aluminum frame that get softer after years of use. Steel and Titanium also get weaker after decades of use as well but not degrading nearly as fast as aluminum. But carbon bike, as long as it doesn't crack by hard impact, it stay the same stiffness.
So, Carbon bike is more of a forever frame than Steel, Titanium and Aluminum bike
Sorry
but steel is much more likely to be in service 100 years from now than CF or even Ti

actual evidence from millions of bikes in use is more convincing than theoretical discussions

if you want to buy a hardtail or a road or gravel bike or commuter and your main concern is; will it still be ridable after 25 years to 50 years of use - get high grade steel
 

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Sorry
but steel is much more likely to be in service 100 years from now than CF or even Ti

actual evidence from millions of bikes in use is more convincing than theoretical discussions

Have you drawn actual evidence from millions of carbon fiber bikes over the years? Or is this just a theoretical discussion?
 

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Evolutionsverlierer
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I don't see any bike frames getting repaired. I know there are companies that do repair I have just recently looked into it. And you can argue that they are busy but if you go to your LBS you will see that it is rare that they get sent out rather than replaced.
I put a hole in the downtime of my carbon bike. Pricing out a repair was going to be about 1/2 the price of a new frame. My LBS got me a crash replacement discount and if I got it repaired I would of had to pay shipping 2 ways.
I also think if I had a current geo frame that I damaged I wouldn't get it repaired because I wouldn't trust it for anything other than a townie. Even a road bike,
 

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Have you drawn actual evidence from millions of carbon fiber bikes over the years? Or is this just a theoretical discussion?
I certainly have over a million observations
More data on steel and aluminum than on CF
But the sample size on CF is way more than enough to indicate the likelihood of a CF being in use in 25 years without a major repair is less than 40%, Steel used daily for 25 years will be fine unless there is a major event

minor impacts on steel frames are no big deal, on CF those often result in repairs needed that cost more than the OEM cost of the frame

i think everyone knows this, honestly

not saying which is best
just that steel is mostly likely to last for decades and decades under normal regular use including falls and such
 

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I certainly hope not
@71 I would like to outlast the average CF frame


How long do you think the average carbon frame lasts? I see 10 year old ones all the time and it's not uncommon at all to see 20+ year old ones still in service.

I take pretty good care of my bikes so maybe I'm not average in that sense. Also though I would fully expect a quality carbon frame to last the rest of my days it's way more likely I'll get a new one while my current one is still serviceable within 10 years anyway. I'd do that no matter what the frame material.
 

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How long do you think the average carbon frame lasts? I see 10 year old ones all the time and it's not uncommon at all to see 20+ year old ones still in service.

I take pretty good care of my bikes so maybe I'm not average in that sense. Also though I would fully expect a quality carbon frame to last the rest of my days it's way more likely I'll get a new one while my current one is still serviceable within 10 years anyway. I'd do that no matter what the frame material.
Never fall on a rock, curb, tree, another bike, an armadillo , turtle or a teenagers head or any other hard object
and your CF frame should last a long time

on the other hand ; high grade steel frame, you can shot it with a 12 gauge and still ride it another 5 decades easy

to answer your question, there are three typical types of averages, mean , midian and mode
I would say mean life of CF frames is under 10 years, mainly due to impacts

note: I do not build steel FS bikes - just AL and CF
but there are reasons for that

but if anyone wants a forever frame, steel is the only proven option under normal riding and treatment
 
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