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Carbon becomes brittle with age?(30 posts)

Carbon becomes brittle with age?wielerpret
Sep 3, 2003 4:00 AM
I was told the other day that a carbon frame has an av. lifespan of a meagre 10 to 15 years. The solvents (or whatever they are called) that make the carbon flexible evaporate over time and cause the frame to become as hard and uncomfortable as if made of ceramic material and equally brittle. I had a greater longevity in mind for my precious and pricey TREK OCLV and feel rather cheated if this is really so. Titanium may be a better choice in that case.
Does anyone know about this?
Luke, Amsterdam.
It melts if you leave it out in the sunpmf1
Sep 3, 2003 4:52 AM
And if you get the bike below freezing, it'll shatter if you drop it.

Really, you should only ride a carbon bike for 2-3 years in 70 degree temps. After that amount of time, it starts falling apart.

Yeah, titanium bikes are way better.
It melts if you leave it out in the sundivve
Sep 3, 2003 5:04 AM
My MTB has (vertically) flexible chainstays which are an integral part of the rear suspension. I asked the manufacturer whether this would pose a problem in cold weather. The answer was a resounding no. I've ridden the bike off road in temps as cold as 0F (about -18C) last winter and it's still okay...I guess there's a possibility that it could be different for a Trek though.
It melts if you leave it out in the sunflyweight
Sep 3, 2003 2:58 PM
You're either joking or wildly misinformed.
Everyone is so serious here ...pmf1
Sep 4, 2003 5:52 AM
Of course I'm joking. When I got my first carbon bike 11 years ago (a Kestrel 200 Sci), I told my office mate that story (one of these steel is real-Campy types who spends a lot more time talking than riding) and he believed it!

I still have that Kestrel and it still rides as nice as the day I bought it. I also have a Colnago (C-40) carbon bike, so that ought to tell you how I feel about carbon fiber as a frame material. Carbon is good stuff!

In the meantime, I've had steel bikes, an aluminium bike and a titanium bike. I kept the titanium bike. Frankly, I've never met a bike I didn't like, with the exception of my old Cannondale 3.0. Ugh.
Everyone is so serious here ...flyweight
Sep 4, 2003 8:18 AM
Sad thing is I still encounter people everyday who say stuff like "carbon melts" or "aluminum is stiffer than steel" (certainly explains why track bikes use steel handlebars!)

Lot of people are painfully ignorant of very basic science.
--->> Well I'm not so sure; you might just want to read this....Synchronicity
Sep 4, 2003 8:55 PM
CF certainly won't melt if you're just out there riding along in the sun.
I don't know about you're climate, but here in Australia, the odd day can get up to 43degC (110F). If you put something made of plastic inside a car sitting in the sun at that temp - it usually severly distorts! BTW everyone should really refer to it as "polymer", anyway, not "plastic".

For example, everyone here knew NEVER to leave cassette tapes on the dashboard or inside the back windscreen (in their heyday at least). What I mean is the plastic cassette itself gets distorted, not just the tape inside. Same most likely happens with CDs. So having said that, there's no way in the world I'd leave a part made of thermoplastic composite inside a car. Some handlbars (scott?) were made of it, so were the old SPIN tri-spoke wheels.

Most CF these days has a thermoset-polymer matrix & doesn't deform until the temp is higher. What is the max temp? I know Kestrel stated it. Does anyone know? Ahh, found it. Do not bake over 150F.

The actual ground surface during one of those days get's so hot it would probably be pretty close to that, if not surpass it. "Ripley's: believe it..... or not"
"Hot enough to fry an egg" is the old saying from an old paint commercial.
So there's no way I'd lie my CF frame on the ground during one of those days. It **would** totally ruin it. People from texas might know what I'm talking about?
Oh spare mepmf1
Sep 5, 2003 5:50 AM
And you didn't even mention your coveted degree in material science (or whatever it is).
Ok then - you bury your head in the sand!Synchronicity
Sep 7, 2003 5:44 PM
But don't have a go at me for attempting to bring some factual knowledge to this forum.

I don't pretend I know everything. Far from it. I believe that old saying "the more you learn, the less you know"
But only in the sense that there is sooooo much info out there & if you (not literally you) aren't aware of it because of ignorance, then you have no idea of all the knowledge out there.

I DO think that there is a lot of speculation out there. Some people haven't studied anything, and they think they can offer a reliable suggestions/advice based soley on their own personal experiences. (Well they can, but usually it's waaay off!)
Honestly, people like you have zero respect for science & engineering degrees. I don't know why I bother.

Then when you /really/ need to know something, we're supposed to come running to your aid.

**pmf1 if you don't like what I write then skip it**
re: Carbon becomes brittle with age?divve
Sep 3, 2003 4:57 AM
I've heard similar stories and also that UV (sun) light accelerates the aging of carbon. I can't substantiate it, however, if it's any consolidation Trek has a good warranty program and I'm sure you'll get a free replacement if they're still around.
Campy carbon crank manual says...the bull
Sep 4, 2003 6:41 PM
not to leave in hot car or expose to high heats.Maybe they will melt! Probally only weaken.
and how old is your car?filtersweep
Sep 3, 2003 5:02 AM
Even if it IS 15 years... what would you want with a 15 year old bike? How many 1988 frames are still ridden? At the rate I'm riding, I'd have about 75,000 miles on mine in 15 years. There'd be no original components anyway- so what is the big deal??
fair point, however...wielerpret
Sep 3, 2003 5:33 AM
...I don't think the next 15 years we'll witness an explosion in new frame materials such as Carbon, Titanium and even Magnesium like we did during the past few years.
Steel has always been around and my trusty 20 year old steel bike I could even bequeath to my offspring if I had any. Appropriate for any $$$ handmade object I should think. Hence my disagreement with you.
I despise all this merely commercial trickery with a vengeance.
Trek backs it up with a lifetime warrantyFez
Sep 3, 2003 4:26 PM
Although the point about 15 year old frames is a good one.

How many of us ride the same bike for over 15 years?
Hummah Hah. nm.Sao
Sep 4, 2003 10:26 AM
Are you sure?Fez
Sep 4, 2003 3:13 PM
I know HH has some nice retro bikes, but does he ride the same one for over 15 years?

I think he bought an old Paramount but has only completed it this past year.
He's had Humma Hah the Cruiser umpteen dozenOldEdScott
Sep 5, 2003 6:07 AM
years. Since the 70s? There've been many tales told about it. It was the world's prototype mountain bike, I believe.

I've ridden my Miyata essentially daily (lately, weekly) since 1984. It's not uncommon among the older, steel set to ride bikes for 15-plus years. At 15 years, the drivetrain's just getting broken in good.
Me. nmOldEdScott
Sep 4, 2003 11:14 AM
re: what would you want with a 15 year old bike?Straightblock
Sep 4, 2003 11:30 AM
You haven't checked out the Retro Forum, have you?

I have a 1986 Santana tandem, a 1984 Stumpjumper mountain bike, and a mid-1970's Laing track bike that all get regular use. They may not be the lightest or latest things on the road, but they're still good rides.

If I were to get back into racing, I'd probably want to have a bike that's up to date. My year-old Bianchi would be fine for that. But many of us also enjoy older bikes, just as others are into classic cars, antiques, etc. Admittedly, everything has a usable life, and a 30 year old bike might not be the best choice for your only bike if you ride 10,000 miles a year, but a bike frame that's given proper care should last many, many years. I don't think of bikes as being disposable, but if you think your bike is worn out after a couple of years or just like to have the latest new bike, more power to you. It puts a lot of barely used bikes on the second-hand market at bargain prices.
re: Carbon becomes brittle with age?hudsonite
Sep 3, 2003 5:24 AM
If you are buying a Trek OCLV, do not worry about it. The warranty on the Trek frame is for as long as you own the bike (original owner only). If something were to go wrong with the frame, Trek will be there to fix you up. The warranty makes the frame material choice irrelevant with respect to durability when you buy a Trek.

There are long-term issues with certain Carbon frames, particularly the ones that mate the carbon tubes together with aluminum lugs. Over time there is a bonding issue between the two materials. Some experts suggest that this frame construction technique will not last more than 20 years and probably less.

This is one of the driving forces to lug-less Carbon frames (eg Look kg486, Kuota Khan). These frames are constructed without aluminum lugs or joints. Without lugs to corrode (or interact with the Carbon), they cannot fail. However there is always some Carbon/Aluminum joints in these frames, like the dropouts or BB. So I guess that these could become a problem with age.

Titanium also has durability issues as well. A German company tests frames and as documented the results of some of their tests.

The test show many frame materials failing with repeated loads applied. If you look through the site, you will also see that the Trek OCLV frames never failed in the tests, while Titanium did.

So for piece of mind, buy a bike with a warranty that matches your needs. The Trek companies (Trek, Lemond, Klein) all offer a lifetime warranty on the frame to the original owner. You will probably find though, as I have, that replacement parts for the other parts of the bike will become a problem long before you have a problem with the frame, no matter which frame you buy.
Reassuring newswielerpret
Sep 3, 2003 5:48 AM
Thanks Hudsonite
Thankfully the market for used quality parts is alive and well...
more ...Jas0n
Sep 3, 2003 10:12 AM
there are companies which mate carbon tubes of the bike together with carbon lugs, and do not use al in the bike at all (i.e. calfee tetra and dfly). when you use ti in the bb, heatube, and dropouts, there is nothing to eventually corrode and the mating of carbon and ti is actaully very stable. its also the perfect wet weather bike, if you can get past riding a 6,000 dollar bike in the rain. i can. maybe you should have gotten a calfee. jk. i have a dfly and a 5200, and expect to get bored with the bikes before any of these issues arrive, if they ever would.
Protective Coatingsbimini
Sep 3, 2003 6:35 AM
My understanding is that it is not age that cause carbon to become brittle but UV rays in sun light. The carbon frame makers us Protective coatings on the finished frames to eliminate this problem.

If the protective coatings get scratched or scuffed it is important to touch up the area with touchup "paint" from the manufacturer.

There are a lot of supersonic planes flying around with carbon wings. Normal life span for a plane is 20-50 years. WITH PROPER MAINTENANCE. I am certain they take great care keeping the UV away from the carbon and the epoxy matrix surrounding the carbon. You will need to do the same if you wish to keep the bike that long.

Personally, I'm a low maintenance kind of guy so high end frames to save a fraction of a KG are not for me.
To touch-up or not ?Steve Young
Sep 3, 2003 7:31 AM
"If the protective coatings get scratched or scuffed it is important to touch up the area with touchup "paint" from the manufacturer."

Is this really true ? - I remember reading in a bike rag recently that scratches to carbon fibre frames should not be touched up but left as they are. This because the risk is not corrosion (as for a steel frame) but because a scratch in a carbon fibre frame is a potential stress riser which subsequently may be a focal point for subsequent frame failure. Consequently the advice was to leave the scratch as it happened and inspect regularly to ensure that it was not "developing".

To be fair this might have been in particular reference to a chain gouge on the chainstay (but I can't remember for sure).

If the manufacturers sell touch-up paint/lacquer/material then this would tend to put the lie to the advice in the bike magazine.

I don't have an opinion on this - just curious really - it's kind of irrelevant for me as my bike is steel :)

Well, If your're really worried...Synchronicity
Sep 3, 2003 5:36 PM
... you could apply sun-screen to your bicycle frame!

A nice SPF 50+ ought to do the job.

That way, you can still keep an eye on the crack, to see if it's developing.

ANYWAY, I hope /I/ am still riding my frame in 15 years.
(The lovely Kestrel 500EMS)
A few years ago (aout 3 or 4) I saw a dude riding around on an old Kestrel 4000. That looked fine & it must have been, what, eight years old?
Carbon PlanesWesman
Sep 3, 2003 8:05 AM
Don't forget about all the carbon fibre fighter jets and bombers in the U.S. fleet. Some date to the 60's. They fly under incredible pressures and wide variety of temperatures.
Carbon Planesflyweight
Sep 3, 2003 2:56 PM
Actually the planes that date that far back are not carbon. The oldest of those only go back to the late 80's.
Carbon Planesbimini
Sep 5, 2003 8:10 AM
The SR-71 used many carbon parts. It is from the 60's. Fastest / highest flying airplane that the military can admit to now.
re: Carbon becomes brittle with age?dotkaye
Sep 3, 2003 10:22 AM
not the carbon, but the epoxy.. a carbon fibre structure is made of a carbon fibre mat and an (or several) epoxy resin. Certainly some epoxy resins may deteriorate over time, typically as a result of UV. But:
1. Trek knows this, so they will apply UV inhibitors
2. since Trek has its lifetime guarantee, anything that happens is going to be covered as long as Trek is in business.

As a general statement, the 'lifespan of 10-15 years' is false. For a particular carbon structure it may well be true. There's no way for us to know..
you are right...venga venga venga
Sep 4, 2003 12:39 PM
...according to calfee. usually the clear coats that applied to carbon frames have a UV inhibitor to prevent the epoxy form deteriorating (like most modern car clear top coats). the folks at calfee suggested i use 303 protectant on my nude (no clear coat) luna pro. the stuff looks suspiciously like armor all though, hmmmmm...