keidal

Do carbon frames have a safety shelf life ?

I am wondering if carbon frames have a useful life, especially with regard to safety and resistance to cracks and breakage. Are there different types of carbon material used and the way in which frames are manufactured ?
I read recently that several Cinelli XLR8R frames had failed particularly at the top end of the down-tube, when apparently the frames were not abused. I would have thought that Cinelli, of all the "big name" manufacturers would not want to be associated with dubious frames.
Having thought over a considerable time, whether to buy a secondhand carbon frame, I have now been told that a frame which is now probably ten years old and even with moderate amateur use, could certainly be structurally suspect and the inference being - do not spend money on an old carbon frame, Cinelli or otherwise.
Does anyone have specialist knowledge of the possible deterioration of carbon or carbons used in old frames please ? The Cinelli XTR8R frame inmy opinion looks attractive visually even though it's perhaps not a particularly lightweight example.
By the way, if I built one up and being 80+, I wouldn't be giving the bike "some stick" !

RobbieTunes

My 2004 XLR8R-2. 15.37 lbs.


Very light, rode like a Cinelli. The wheels were inferior in durability to the frame.


My 1989 Centurion. 17.4-17.5 lbs.

Now has DA9000/Velocity Aerohead wheels. Don't waste DA9000 money on a 30-year old carbon bike. Let me do it.



My 1987 Trek, right at 17.0 lbs.
This bike could enter any crit and would be well matched with the Cannondale SC's and Criteriums. Which means side by side with the modern stuff. Shelf Life? Hmm. Ask BF member ldmataya about his pair.


Kestrels have been running around for 30+ years. Some of the carbon frames are more susceptible to misuse, storage damage, etc, just by design. Some are not. I find an abused or hard living bike is the same no matter the frame material. The most susceptible I've seen are the OCLV Treks, but let's face it, people beat the hell out of them.

Look the bike over, and ride it if you can. These bikes, over the years, were under Tour riders, on the Paris-Roubaix, and other places. They did as well as any bike ever has. If there is a particular issue (such as the early XLR8R, maybe?) it would be documented by now.

What you've been told is not what we find here on Bike Forums, C&V. You may hear it on the Road Forum. We're older, heavier, slower, smarter, are better endowed and the women love us. Take our word for it.

repechage

Any used item needs to be looked at carefully.
I am skeptical of any carbon frame where one can see the structural weave, (a number of frames have an outer layer that really is just for appearance- but how do you know?)
A good question.
One thing I can state is that the structural resin that holds the fibers in place is vulnerable if you can see it.
So, the more UV exposure the worse off. How much is too much? Who knows.
I think the later carbon frames where there is an opaque top coat all things otherwise being equal will be better off.

uncle uncle

Maybe there is a "use by" date on there somewhere...

Steve Whitlatch 

Carbon bikes look good on a shelf. I am sure they would last a long time there.

Tape2012

The epoxy in unpainted carbon fiber frames may yellow over time (years), but this is purely cosmetic and does not affect the integrity of the frame.

I can't state for certain what the 'shelf life' of an unused carbon frame is, but it's certainly longer than you or me. Or our children.

RiddleOfSteel

This is a valid question, IMO, for carbon bikes that are vintage now as well as ones that will be vintage in time (aka the ones made today). The scrutinizing is still the same in any case, but I think it's more important with carbon. I don't know but...I'll be looking at that stuff from now until whenever. I just have to find that perfect combination of condition, looks, and height/"tall enough" with "tall enough" being the tallest order. Seems a number of carbon frames were designed to look great at 56cm give or take, and by the time 61-62cm are reached, they are pretty ugly.

Wildwood 

1999/2000 Calfee TetraPro, 60cm, 3.0lb frame with Ti dropouts, bb sleeve. 19.2lbs as built with Campy 10 (mix), 1" full carbon threadless fork and tubular wheels.

Has not yet outlived the 25yr frame warranty. Ridden regularly.

cpach

It's harder to see structural damage to carbon frames so it's more risky to buy used equipment, and as with anything there are products that are poorly manufactured (in metal bikes too!), but if a carbon frame does not degrade under normal riding conditions and can have an indefinite lifespan. Carbon can be damaged by forces that would not damage a metal bike, as carbon bike frames are more likely to be damaged by impacts to sharp objects and crushing forces.

That said I wouldn't buy a frame with a known history for structural failure regardless of material.

Tape2012

I agree with what you have said.

The main concern for me is that building a quality carbon frame takes more skill and diligence than metal frames. It is easy to build a poor quality carbon frame with thin spots and inconsistent wall thickness and all of that is impossible to see once a frame is built without expensive imaging or other non-destructive testing.

Having said that, I think buying a 10 year old carbon frame may be as safe or safer than a new frame. If the frame has survived 10 years, your past the point where failures from mfg defects should have manifested. Consider it 10 years of non-destructive testing.

Chombi1 

My 1972 Line Seeker. It's still alive, despite its close to half a century age and I still ride it once in a while but could really be riding it more but the horrible Fiamme Ergal rims won't stay true for me for enough miles to do so......

Johno59

It is important to be able to stand up on the pedal.

Lean on a wall or get someone to support you.
​​​​​Place all your weight on the lowered pedal and observe the amount of BB swing to the opposite side away from your foot. Rotate the crank and do the same for the other side. Don't be shy, try to break it.
The swing should be nowhere near as much as your favourite steel bike. Plastic bikes were designed to alleviate this problem and thus transfer more power into where the rubber meets the road and less into the frame as per steel bikes. Good carbon is untouchable in this regard hence its propensity with all pro cyclists.

If it looks excessive or feels spongey the layers of carbon and resin thruout the bike's triangle have begun to delaminate. The frame is a write off.

Unlike a bent/repaired/dinged metal frame the owner could be innocently unaware the frame is toast and is selling it on in good faith.
Just visual the rest as you would any frame, forks are obviously replaceable but the triangle is not and a delaminated frame will continually delaminate until the bike becomes unrideable in a straight line.

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fietsbob

epoxy is damaged by UV like all polymers so a dark closet is best.

Bikerider007

The concern most seem to have is how they go when they do.

CliffordK

Shelf life is probably not an issue, at least if kept from getting dinged up and out of the direct sunlight.

The one issue is likely a slow evolution in design. Metal lugged to carbon lugged to monocoque.

The OP asked about failures in 10 to 15 year old "Name Brand" CF frames. If a failure mode had been identified by a reputable company, then it would have been fixed long ago... in the newer released frames.

So, the 10+ year old frame wouldn't have all the latest improvements.

RobbieTunes

There is little empirical data supporting anything above negligible power loss from BB and frame flex. I always see this argument. It's nice to think anyone reading this has ever had that "power loss" affect their ride one iota, but that would be BS. I have never seen a photo finish in a triathlon and sprints are won by strategy and wattage.

Pro cyclists ride what they're told and many wish for less stiff frames.

ingo

I am currently testing the premise that carbon frames have a limited life. My 1992 TVT was raced for 3 years, then ridden for training for another 15 years. Total of >35,000 km. Now it is on Kickr trainer for Zwift, and has done more than 500 hours (~16,000 km) including races and 900W sprints. People say that the old carbon frames will blow up under such "abuse" especially on a trainer, but to me this is what the frame was designed to do. My view is that if the frame is not crashed, it should last longer than you would want ever want to ride it, at least 50,000 km?

keidal

Thank you for all your comments.
I suppose that if exposure to sunlight / daylight has a detrimental effect on carbon frames, then the same concern should be shown to other components [handlebars etc.] which don't usually have a "protective" paint finish, as most bicycle frames do ? The failure of any of these components could be very dangerous indeed.
I wonder if the car and motorcycle companies producing carbon bodies / chassis etc. have any structural concerns reference sunlight / daylight !
Does the number following XTR8R on the Cinelli frame have any reference to the year of manufacture or frame size etc. please ?

Johno59

You don't lose power you lose acceleration. If the frame is bending that absorbs your power and thus there is less transferring to where you want it - where the rubber meets the road.

But we are talking folks who generate 2000 watts here. If you watch the sprint finish featuring top sprinters the rear wheel literally skid sideways as the frames are so rigid. A steel frame would fishtail under such extreme power and the man on steel would find himself being left behind - not for lack of wattage but less efficient power transmission.

Triathlon bikes rock you over the BB and onto the aerobars to provide speed, rest and sparing your running muscles- a different suite of determining factors to road racing.
I personally am nowhere fit/strong enough to tap into the obvious advantages carbon gives to riding a bike and as such choose to avoid the disadvantages.
If a carbon bike hasn't been damaged or not been placed under elite pressures it should last a long time. Resin does change over time, but as to how long ageing becomes a problem who knows. The aircraft industry promises 40 years and it is early days on proving/disproving that promise.

Colorado Kid

As they say, " Steel is Real." Never had worry about such stuff with my Steel bike.

repechage

UV degrades the epoxy. It is the epoxy that stabilized the fiber matrix. if that breaks down, you have a near equal to a bundle of carbon threads. this is separate from the clear coat paint failing.
There is a magazine that has had articles about and surrounding this over the years, Professional Boatbuilder. There was a short time where guys who bought carbon fiber rigging wanted to show off the carbon, that is passe.
Also, online forums for the "rice burner" Asian Import hot rod car crowd lament the short life of carbon fiber hoods, outside mirrors, trunk lids where the weave is visible and the sun attacks.
True, a car will probably see much higher UV load over time than a bike, but the process is the same. Kestral and Calfee where they painted the frames - a terrific job of protecting from UV.

Salamandrine 

Nice. The Calfees are the one carbon bike I'd consider, if I had room and money for more expensive bikes. The 25 year warranty on many of their models is reassuring. I get the idea that they use the best available aerospace materials. I don't get that feeling with the mass market companies' bikes. Also, they are made near my hometown, which is kind of cool.

In general though, I wouldn't expect many carbon bikes to last that long. It isn't the carbon that breaks down, it's the resin.

Wildwood 

I lived a few miles from the factory. Test rode Trek, Aegis, Kestrel and many others. Didn't ride a Colnago. It was clear at the time that the carbon tubed bikes had a significantly different road feel than monocoque frames that absorbed too much road vibration - the 'dead feel' or the 'wooden feel'. Craig was/is such a good human - let me demo bikes, showed me his first carbon tandem (to ride with his daughter), got to ride (briefly) an early bamboo prototype, etc. Took me 2 years to convince myself carbon wasn't a fad and pull the trigger on the Tetra with Ti bits over the Luna with Al bits.

Tape2012

Yes and no.


It's the quality of the materials and the quality of the build that determines the quality of the bike, just like any other frame material. But a well made composite bike will be around and ride-able longer than any metal frame bike, especially aluminum. All composite manufacturers (one of which I worked for) add UV stabilizers to the resin to prevent or significantly slow UV degradation. Although in practice with any frame material, a well cared for, maintained and properly repaired bike frame will outlast any human owner, which kinda makes these comparisons academic.


I think that composite bike frames get a bad reputation because people don't understand the properties and limitations of the material and that anyone who has ever fiber-glassed a car or boat repair feels like they can build or repair a composite bike. That is just not true. Composite bikes are (with certain limitations) stronger, easier to repair, and longer lasting. Now, I could walk up to your composite bike and stomp on a chain stay and break it. That's because the chain stay wasn't designed to resist forces in that direction. That doesn't mean it is fragile. Just like the composite air frame of a Lear jet can be expected to last for decades and millions of miles but an accidental bump or wing strike can easily cause damage.


I see a lot of posts about composite bikes just failing with no warning. While I am sure that has happened, just like with any frame material, any damage suffered by the frame that would lead to catastrophic failure is almost always visible and easily detectable at the surface. Also, a bike that has been in an accident can be inspected by a competent person with sonographic, IR tor any number of NDT technologies

Wildwood 

Santa Cruz area of Monterey Bay is a universe away from Los Angeles. Maybe in a neighboring state soon?