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An LBS mechanic told me that the usual lifetime for carbon frames and most carbon components like handlebars are 2 to 3 years, and after that there is a risk of developing cracks!!:mad:
What is the truth behind this info??
 

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Yes anything is possible if you constantly putting load on the parts. Like in testing environment, if they project to last 1 million cycles and it ended up doing 2-3 times more.

Does it happen to a properly installed and maintained bike in that time frame? Unlikely. If it is we'd seeing all kinds of lawsuits.

Most will start cracking? That guy is a retard.

No worries;)
 

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Realistically, I would be far less concerned of the fatigue life of a carbon frame than an aluminum one. Unless it is subjected to a chemical or heat extreme, an average use xc frame would not have a set 'limit'. That does not mean an indefinite life per se, but it would mean a different life prediction system. I would call it an on-condition basis, similar to steel. Unabused, it should be good unless you find it damaged(profound, eh?).

In aviation composites(which are used very frequently in high stress areas), the simplest check is to tap lightly with a metalic tool. Not hard enough to ding the paint but learn what resonant sounds like. If the sound changes or goes 'flat', check it closer. Joint areas and metal interface areas would be the first areas to fail if produced/designed improperly.
 

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In general carbon will outlast aluminum. Aluminum has a definite fatigue life. Carbon does not. As long as you aren't bashing the carbon on rocks all the time, or over tighten derailleur clamps, brake clamps etc. it should last a long time. The weakness of carbon fiber is the epoxy, it can be cracked by impact and damaged by UV light (but clear coat or paint protect it from UV light).
 

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If the frame is built like it should (FEM calculated and properly sealed against moisture), carbon fibre structures are not at all prone to fatigue failure. The problem is, that you generally don't know if the manufacturer knows what he's doing.

Aluminium on the other hand, will eventually break after a (great) number of loading cycles, if it's not extremely rigid and heavy.

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What bike shop would push a customer towards a carbon frame knowing it has a 2-3 year lifespan only. I certainly wouldn't buy from that shop or that vendor.
Most reputable builders have 5 year warranties on their carbon frames and Cannondale has a lifetime warranty on carbon frames as long as you are the original buyer/owner of the bike.
I would guess you are dealing with shop employee who has his own opinions of carbon frames, not the bike builders or the bike shop owner for that matter.
 

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The carbon proponents will always come up with some test
which 'proves' that carbon lasts longer. The industry can cook the books to make iy look
like carbon lasts longer, but as they say, the (real) proof is in the pudding.

Carbon frames are NORMALLY replaced every 2-3 years and in general will not even come
close to alumunum in the time you would be able to keep our frame with out it developing
ttypical 'cosmetic' defects in prone areas.

Even the best made carbon frames will eventually develop cracks in the most stressprone areas, i.e.,
BB shell and other places that see a lot of contact from small rocks and such. Carbon can be
incredibly strong in a given direction, and would generally exceed the stiffness of AL franes,
at least in the direction that the weaves are aimed at, So carbon has some ride qualities
that exceed AL, and can alspo be molded into exotic eye candy, so they are great showroon stoppers,
and you can do a lot of advanced shaping processes that youo can't do with AL.

However, as far as the ultimate endurance of the frame, aluminum is superior because of its more
ductile, doesn't weaken or chip with repeated strikes to the same region of the frame.

If the carbon frame sees mosstly XC type riding, and you live in a region without a lot of fast
trails with loose rocks, I'd say it would be worth getting the carbon frame, as it in this type
of riding situation could last much longer that the typical 2-3 year figure that is hte most
bandied about in reference to the lifetime of carbon frames.

On the other hand, if your rides involve mostly AM terrain with lots of sharp loose rocks,
(thinl places like Tucson, AZ), aluminum is more of a sure bet as far as longevity goes.
Since AL is more ductile, you generally won't get sudden catastrophic failure as you would
with carbon, since you can easily inspect AL, whereas with carbon, smallish cracks that are
usually referred to as 'cosmetic', with continued stresses will eventually spread into
the deeper layers and become something more than just on the surface layer (cosmetic)
over time.

I'm not trying to denigrate carbon, I think it can offer substantial weight saving in xc
applications, and some superior qualities over AL in that arena.

But if you want to be sure that your frame will last more than a few seasons, and you
don't want to be bothered with the posibility of needing frame fixes during that time,
than a well constructed aluminum frame is the way to go. I've done a few decent rides on fs carbon
bikes and had sno issues with them. If I could afford a 'quiver' of bikes or had the means to replace/repair
the frame when necessary, I would definitely have a carbon bike in my stable of bikes.
But if I could only afford one do-it-all bike that I could ride with confidence for more than
a few seasons (my situation) then your best bet is to stick with good old aluminum
 

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Airplane parts are made of carbon and last time I checked that was a pretty critical and highly tested and regulated application. But plane bits are replaced after crashes and xrayed etc. I for one don't feel comfortable buying a used carbon frame. Maybe perception or something but hear of carbon failures

Sent from my SAMSUNG-SGH-I997 using Tapatalk 2
 

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Carbon should last the longest of the typical frame materials as long as it is properly sealed from the elements and not crashed. :nono:

Properly designed frames which are much more the norm these days than a decade ago, can be overbuilt in all the areas that other frame materials cannot be, for ex. steel particularly inthe area of the bottombracket, etc. Thus it should at least outlast a steel frame which one can typically expect somewhere between 35k miles to 50k miles lifespan barring any collision damage. Collision damage and uv exposure are about the only things to worry about. Btw, uv damage is pretty much a non-issue with standard production methods. Also it's easy to throw on a uv protecting clearcoat.
 

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Carbon should last the longest of the typical frame materials as long as it is properly sealed from the elements and not crashed. :nono:

Properly designed frames which are much more the norm these days than a decade ago, can be overbuilt in all the areas that other frame materials cannot be, for ex. steel particularly inthe area of the bottombracket, etc. Thus it should at least outlast a steel frame which one can typically expect somewhere between 35k miles to 50k miles lifespan barring any collision damage. Collision damage and uv exposure are about the only things to worry about. Btw, uv damage is pretty much a non-issue with standard production methods. Also it's easy to throw on a uv protecting clearcoat.
You're crazy, I had my steel hardtail frame for 15years before it got stolen. It was still in good stat even though it had developed a little rust from my locking it in an outside bike rack for a year. Can you honestly say a carbon would last any where near that
 

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You're crazy, I had my steel hardtail frame for 15years before it got stolen. It was still in good stat even though it had developed a little rust from my locking it in an outside bike rack for a year. Can you honestly say a carbon would last any where near that
Remember your rigid steel frame weighted 5+ lbs. i bet a carbon fiber rigid frame of the same weight would outlast it and be rust proof too.

No M.E. here but in "theory" the carbon frame will out last your steel because a carbon frames is designed from the start to be stronger. In the old days 3x stronger used to be throw around but if you watch those Santa Cruz frame destruction videos it looks like the lighter carbon frame is only 50% stronger to its alloy counterpart which is still a lot and it translates into the stiffness we all feel. Not a roadie so don't know if this still holds true today but 10 years ago my tri-athlete friends would crack their ultra-light carbon race frames at the bb within 3 years so they would sell them every 12-18 months, maybe this is where the LBS mechanic got his 2-3 year theory from.

So think of a carbon frames vs other materials like an XC frame vs a DH frame. Carbon frames are over built because they have to be. Carbon does not have elongation and compression number that metals do. Specialized is making this very claim to justify alloy rear triangles.
 

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An LBS mechanic told me that the usual lifetime for carbon frames and most carbon components like handlebars are 2 to 3 years, and after that there is a risk of developing cracks!!:mad:
What is the truth behind this info??
Total bs only because what if i only used my bike 3 times in this 2 to 3 years? How can someone give a time-span life cycle? It has zero basis.

I don't care for carbon frames myself. I've helped two friends with three different carbon frames do a teardown and rebuild with a new replacement frame due to cracking. Frames with less then 300 miles too! Reputable manufacturers also.

Yup, they can show those cool carbon destruction vids, but what they don't show is the other high stress areas like seat tube to seat stay cracks. Suspension pivot points. The are all areas carbon frames I've seen have consistently cracked. Sorry, but the bike industry has not perfected carbon yet.

As far as planes being made of carbon.... Ask Boeing how their Dreamliner is working for them.
 

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Airplane parts are made of carbon and last time I checked that was a pretty critical and highly tested and regulated application. But plane bits are replaced after crashes and xrayed etc. I for one don't feel comfortable buying a used carbon frame. Maybe perception or something but hear of carbon failures

Sent from my SAMSUNG-SGH-I997 using Tapatalk 2
Airplane parts are also made of aluminum, wood, fiberglass and even fabric. Planes are not really subjected to heavy stresses fyi.
 

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Not all aircraft components are heavily stressed but certain components are. I assure you the manufacture of aircraft components are under far greater scrutiny than the manufacture of a bike frame. Also, they are regularly inspected by during maintenance and annuals.
 
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