143gadgets

I was told by a friend of mine that carbon frames have a limited life. Is this true? After so many miles they tend to not be as stiff?

Shinnster

Technically all bikes regardless of material wear out.

If not abused, i believe carbon is one of the longer lasting materials. longer fatigue life.
aluminum might be shortest?

You would have to put some serious miles to wear it out. serious like ridiculously serious.

MONGO!

Carbon doesn't fatigue.

txvintage

Eventually they turn into diamonds.

Seriously though. There are Carbon frames that have been out there sine the early 90's and the technology has come a long way since they were built.

desmodici

Don't believe the hype. I have an aluminum frame Cannondale mountain bike that I bought in 94 that is still going strong after 15 years of hard trail use. I remember reading articles when I was buying the bike saying that aluminum has a 10 year max life, and that Titanium was the way to go. By the time any of these bikes reach the end of their usefull life, you will have upgraded bikes 4-5 times.

Metzinger

Carbon frames experience a limited life span of their aesthetic appeal.

patentcad

It's not really a problem if you follow Standard BF Protocol and replace it every two years with a brand new $4K-$8K road bicycle.

TrippleB

if you are worried about your new cf bike wearing out (like an S2 for example), then you can always buy a cheap bike to ride around and train on (like a motobecane for example).....hmmmm i think i can recall a BF member who does that

ride your bike and ride it hard. CF is strong stuff and extremely resistant to corrosion from water and grime. provided your frame wasn't engineered by idiots and you don't crash it, you will grind several BBs into paste, break your crank arms and wear enough steel cogs and chainrings down to the nub to build yourself a new steel lugged frame before your CF one wears out.

The Weak Link

Just don't leave it out in the sun or it will catch fire.

rangerdavid

+1

:d:d
rd

coasting 

my bike suits me just fine. i intend never ever to get another bike. ever.

i said it 3 bikes ago too.

Trucker Dan

I know a guy that just got a crack in the bb area of his 96 carbon trek. It had over 50,000 miles on it and had been crashed several times. Trek is going to replace the frame under its lifetime warranty.

coasting 

if companies are offering lifetime warranties, it suggests that they generally don't expect frames to wear out.

jrobe

Somday someone will do "carbon dating" on your bike and it will be 30,000 years old.

bigtea

Norcal_Cyclist

I have a '94 Trek 8700 that has CF tubes and Al lugs. I was told the glue at the lugs would de-bond or the CF wear out by nay-sayers when I got it. Here it is 15 yrs later and I have well over 20k miles on the bike and still have it as a "ride around the MUT or neighborhood with kids" bike (and for sentimental reasons - first CF bike and from wife). CF is a durable material that is not going to wear out - at least not before you have decided you "need" a new bike or have crashed it (CF doesn't fair as well as metal frames in crashes).

143gadgets

Thanks everyone for the info!

BigBlueToe

There was some show I watched about factories and how they build stuff. One was the Trek factory and it showed them making Madones. They wouldn't show everything, like some of the carbon layup, which they said was proprietary and secret. But they did show the stress testing of a complete frame. They had it in a machine which bent various tubes back and forth, repeatedly. The amount of stress they were putting on the frame was far more than a rider would do - even a 350 pounder. They said it could withstand the abuse for an almost unlimited number of cycles - far more than a rider would do in a lifetime of riding.

It impressed me.

Ames

Mine has a life time warranty but I do not but I do plan to live till I break and die. I bet it outlasts me.

benajah

Carbon frames dont wear out really. A lot of the "durability" issues come from the relatively fragile reaction to impacts, nicks, dings, etc. You simply cannot treat a carbon framed bike the same as other materials in terms of storage, transportation in a car, etc. I lean lumber in my garage up agaisnt my Al bike all the time, but I would never lean something on my carbon framed bikes.
If you babied the frame, and really protected it, you could expect a good carbon frame to last at least as long as an Al frame.
Think of it like this, light carbon frames are built to be ridden, and nothing else. Treat it like that and it will last a really long time.

BillyD

Should I do the explosion?





Naaaaw, too easy.

rooftest

There was a show on Discovery Channel where they visited the Trek factory. This is one of the points that Trek made. An impact that doesn't break or crack a steel frame could still weaken it. With carbon fiber, if the impact doesn't break or crack it, it's as strong as before.

bigtea

Or, to the layperson, carbon fiber is not elastic, it is brittle.

Sundae

That's actually a really bad way of working it for a layperson, because they don't think of brittle as meaning what it actually means. They think of brittle as "really weak and cracks easily" instead of just not capable of high %s of deformation.

It'd be better to just say "Carbon takes a ****load of force to hurt it, but if you manage to hurt it it'll break". That'll get the point across well enough.

DannoXYZ 

My 1991 Specialized Allez Epic is still going on strong after over 60k-miles, 10-years of racing, numerous crashes and 2 replacement forks.

Carbon-fibre like any other material such as aluminium, steel, titanium, have a fatigue and ultimate strength limit. The engineers design a useful lifespan in fatigue-resistance much, much longer than you'll keep the bike. If you apply enough force, like hitting a tree or hitting a garage-door or getting run over by a semi-truck, yes, you can overcome the ultimate strength of the bike and it WILL break.

During my 10-years at a shop, I made A LOT of money on selling Specialized carbon bikes with a simple demo. I had 6" section of Columbus chromoly steel, 6" section of Cannondale aluminium tubing and 6" of carbon-fibre from an Allez Epic bolted to a board. I told people to take a hammer and whack each one as hard as they wanted. The steel and alloy tubes both squished and the CF was intact with a slight chip in the clearcoat. Guess which bike people bought after that demo? And I got a $250 commission in my pocket, ka-ching!!!