Carbon frame "life expectancy"

I'm not sure exactly how long a carbon frame would last however Trek backs their carbon frames with a lifetime warrenty.

cpalomo:

Carbon fiber does not have a life expectancy.

Eventually, all metal frames will fail if used long enough due to the finite life cycle all metals have. Your old Pinarello has tons of cumulative stress worked into the metal. Time for a replacement for sure.

The only way carbon can fail is with a catastrophic load at which point the tubes break completely. Don't worry about that happening. Whatever stress you could give to break a tube, a metal frame would fail first, then carbon.

Carbon fiber is the strongest frame material you can buy. The metal parts glued into all carbon frames are the weak links you have to worry about.

Modern carbon frames are highly durable, more than any other frame you can buy.

Trek frames are very good and they will take care of you if there ever is a problem. They were good before, but in the last few years have improved even more. 5200's/5500's are excellent frames!!!

Enjoy your new bike!!!

J-MAT:

Thanks for your reply! It was both informative and encouraging. It backs up a lot of the information I am finding about modern carbon frames from my research.

cpalomo

My knowledge of carbon is limited, the post above is well written, however it did not address a few questions I have about carbon frame, and it had one part that I found in conflict with information I have received from other manufacturers.

I have heard the following statements from independant sources:

Carbon fiber should be replaced or repared if it suffers a cut or scrape to into the fiber themselves. (Which seems like an annoyingly difficult problem if you lean your bike against things)

Ultra-violet radiation can weaken the breaking load of Carbon.

Steel and titanium only fatigue if loads abnormal (possibly unheard of) for cycling are placed upon them. Where aluminum fatigues at any load level, ie. every pedal stroke contributes to the frames death. As for the "all metal frames fatigue and eventually fail" statement, that is not a realistic view to take. How long are you going to live? Steel and titanium are going to outlast you by far, and titanium will outlast your children. I have a freind who rides a penny farthing it is 110 years old, and it is still used for training. She won the 2002 high wheel world championship in Belgium, I don't know if that was her competition bike.

Carbon is not a comfortable material, with no flex, all of the larger shock are transmitted directly into you rather than being stored in your frame as potential energy and then with a slower acceleration springing into you. Carbon absorbs high frequency vibration though, so a carbon fork or rear triangle is good for your comfort.

Other than those concerns, I would test ride carbon vs other materials extensivly. It may be a cool concept, and have benefits, but, steel seems to be a great material for me.
check out
www.serotta.com
They have reasonably priced custom steel and titanium frames. They have been the source of innovation and cutting edge design in the cycling community for decades, if you ask them a question, I am sure they would give you good information.
I am sorry to potentially confuse the subject even more, but, I view a frame as a serious investment, and the years you got out of your Pinarello are testiment to the materials used to build it. Steel and Ti are the way to go from the research I have done, and I have spent many many hours learning. I have a hole in my knowledge about carbon which is what brought me to this post. I have heard some good things, but, I want comfort first, so I am still sticking with steel (price and function steel is a better choice for my budget than titanium)

-Jacob

Can:

Let me say that I have had bikes made from steel, titanium, aluminum, and carbon fiber. I like aluminum and carbon the best, which for me means Cannondale and Trek.

There are several different ways carbon can be made into a frame, and they differ in the way they look. They are all strong and don't scratch easily or break easily. Worry about your skin burning in the sun, not your frame.

All metals fatigue, that is the nature of metal. It doesn't matter what the material is. Aluminum failures are bad because aluminum doesn't slowly bend when it fails like steel, it snaps completely making for bad crashes.

If you ride hard enough or long enough any metal frame will fail. All metals have "life cycles" which is the number of stress cycles it can take before failure occurs. Every pedal stroke on a metal frame contributes to it's death, it's just that some have longer lives. Most people won't ever get a steel frame to fail, but the longer you ride it, the more stress you will put into it.

Carbon fiber IS the most comfortable material you can make a frame out of. Carbon frames absorb shock better than any other material.

Steel is actually one of the best materials for frames. It's very comfortable, and rides well. It's a little heavy though. A great value for sure.

My least favorite material??? Titanium by far. I can flex a titanium bike like a wet noodle. If you are big or strong, or big and strong, titanium will provide a ride that is probably way too soft.

Carbon can not "soften" as some detractors claim. That is physico-chemically impossible! It certainly does give a comfortable ride provided it is well made. I recently bought a Bianchi carbon which is far more comfortable than my old steel bike. I test rode the Trek 5500 and the Bianchi has a more lively, less wooden feel than the Trek. Also, there is a fair chance that you will have to replace the crappy headset that comes with the Trek.

A good carbon bike should last you a long time. A light weight steel (eg ultrafoco) probably won't. If you ever see ultrafoco after a crash - it is like aluminium foil - hence you will be lucky to get more than a couple of seasons on it.

Titanium is a very hard metal to work with. Any flaws in it will weaken it greatly. If going for titanium, select a company with plenty of experience that gives a lifetime guarantee.

There is a lot of good info here and there is quite a deal of bias...

Quoted post said:

A good carbon bike should last you a long time. A light weight steel (eg ultrafoco) probably won't. If you ever see ultrafoco after a crash - it is like aluminium foil - hence you will be lucky to get more than a couple of seasons on it.

Depends on how you take care of the bike.

1) If you don't prep the inside of the steel bike with some type of frame protector such as J.P. Weigles' FRAME SAVER then it could rust from the inside out. If you don't take care of chips in the paint then it coulr rust from outside in.

2) I've seen carbon break in a crash. And when it breaks there is no chance of riding it. A metal frame may take a ding whereas a carbon frame would shatter. Also the metal can survive a ding whereas carbon with cracks or deep scratches will only get worse over time.

Quoted post said:

Carbon fiber IS the most comfortable material you can make a frame out of. Carbon frames absorb shock better than any other material.

Steel is actually one of the best materials for frames. It's very comfortable, and rides well. It's a little heavy though. A great value for sure.

My least favorite material??? Titanium by far. I can flex a titanium bike like a wet noodle. If you are big or strong, or big and strong, titanium will provide a ride that is probably way too soft.

Opinion...

1) Carbon is the "most controllable or mailable" It is not the most comfortable. Comfort in carbon only comes from know-how.

2) Steel can make comfortable frames. It is not really so much it is heavy but it does have problems with maintanance.

3) Ti... Well here I am biased because after 16 years of riding quality steel I think the exact opposite of Ti than this... Plus Ti serves simillar life-time as that of Carbon. Long life due to lack of rusting away but will eventually hit a lifecycle issue.

Quoted post said:

There are several different ways carbon can be made into a frame, and they differ in the way they look. They are all strong and don't scratch easily or break easily. Worry about your skin burning in the sun, not your frame.

This is true and false. Different frame designs are possible... This is true... What does this mean? It means that not all carbon frames are equal. you must be very careful in choosing a ride as one design can differ vastly from another.

What is the false side... Scratch and break easy. Other than mountain bike Aluminum frames, the second most common frame I've seen fail is Carbon. And if not fail, scratches. I've seen bottom brackets pop open in sprints (trek), delaminations due to oils penetrating cracks in the paint (Kestrel) and I've seen deep gouges into the BB shell caused when the chain poped off the small ring while a guy was hammering up a hill and the darn chain dug right into the shell and hung fast.

Quoted post said:

Carbon fiber should be replaced or repared if it suffers a cut or scrape to into the fiber themselves. (Which seems like an annoyingly difficult problem if you lean your bike against things)

Ultra-violet radiation can weaken the breaking load of Carbon.

This is one of the better infos in this thread...
Add this along with the comments about metal cycle lifetimes and you get a good picture of all the materials talked about in this thread.

Don't forget to be careful where you get grease and lube on that frame too as the solvents can penetrate the scratches in the paint or down the seat tube and the 'poxy can begin to soften...

Quoted post said:

Carbon fiber does not have a life expectancy.

This is just flat out wrong. And Trek knows it... And so would anyone riding a bike, well almost anyone. All parts have lifetimes...

Quoted post said:

I'm not sure exactly how long a carbon frame would last however Trek backs their carbon frames with a lifetime warrenty.

True. And so do many non-carbon frame manufacturers. Now to finish my say...

It seems the good modern frames, such as the trek 5200/5500 have simillar lifetimes to that of a Ti or well maintained steel frame. A friend of mine has as 5500 and I think he said that the duty cycle of the frame was something around 24,000 miles. I'm going to check with him tomorrow on this... I know that he knows the actually rated life of the frame as he was telling me a few rides ago that he was about to go past that point in miles recorded on his cycle-computer.

I also wondered that as I am using carbon for my fork and carbon spokes (was spinnergy but now topolino)...

I replaced the fork at 12,000 miles "just because" no one could tell me how long a carbon fork should last.

Later I read that either Rynolds, Easton or Look run tests that simulates like 14,000 miles so I guess that could be a resonable limit... Though I think it is actually longer... Probably the same as the trek frame of 24,000 miles.

Again I'll post what the trek rated duty cycle is for Carbon when I get it tomorrow.

But again to conclude... Carbon should give you the same life as Ti or good steel... Just watch the scraches, sun, and oils/lube and you should be fine.

John.

quick reply,

First, thank you all for your input, I have more to draw from in future decisions.

Second, titanium as with any other frame material can be given differant properties based on how it is processed and the shape of the final product. There are companies out there making titanium frames with oversized, ovalized, and probably more techniques to reduce the flex. I am an endurance rider, though I am 170 pounds of leanish cycling specific muscle mass, I cannot flex most frames I come across unless I am sprinting up hill, but, again I live in Illinois.... pretty flat (unfortunatly? *shrug*)

Thanks for the backup John, it is always nice to have some validation.

In summery, all the materials we have listed can be made into bad-ass frames, it all comes down to your preferences regarding fit, function, comfort, and maintanance. So if you want a carbon fiber frame go for it, I have been checking out the Look ones myself, they are very pretty! Not quite as pretty as a De Rosa Cuore in the second paint option, than again nothing is....sigh

prestonjb:

first of all, carbon fiber is a fatigue free material. All metals are not. For carbon to fail, it must recieve a catastrophic load, at which point it or any other frame material will fail.

I've owned frames with made from every material going. My carbon bikes regardless of manufacture were by far the most comfortable. I put well over 50,000 miles on my first one before the metal dropout glued into the rear triangle snapped. I weighed about 185 pounds and put 12,000-15,000 a year on it, and used it for training and racing.

Anyone who knows anything about frame materials, knows that titanium is by far the softest, most flexible material you can make a frame from. I spent a lot of money on a titanium frame from the most famous Ti frame maker in the world, who specializes in "oversized" tubes that were supposed to not flex.

At 185 pounds, I could see the big ring physically move a few millimeters and rub against the front derailleur on every pedal stroke when climbing out of the saddle. It made a nice metal-on-metal grinding sound too!!! How many track bikes do you see made from titanium??? Maximum power transfer does not take place when your frame is flexing like a noodle.

Carbon frames do differ in how they are made. Improperly designed/made carbon can fail. What about a metal bike with bad welds??? That will fail just as easily.

Steel is not that heavy??? Well, it's absolutely the heaviest material you can make a frame from. Steel frames typically weigh up to twice the weight of carbon/al/ti frames.

I've seen all kinds of failures on all kinds of bikes. Most people underestimate the catastrophic forces of crashing at high speed. All frames can easily snap under these conditions.

A Trek duty cycle of 24,000 miles would be only 2 years of 12,000 miles (250 miles a week), which many riders do. Let's make it 6,000 miles over 4 years. 6,000 miles a year, works out to around 125 miles a week.

Anyone with a 5200/5500 put more than 125 miles a week on their bike over 4 years??? If Treks failed the way you claim, they would be out of business, with the every person breaking their frame in only a few years once they hit the critical "24,000" mile "limit."

Like I said, I had over 50,000+ plus miles on my first carbon bike and the metal failed on it not the carbon.

If there is a problem with a carbon bike, it's not because it's carbon, it's because it was poorly designed.

Look at the critical use applications of carbon fiber from reinforcing bridges to superbike motorcycle wheels to aerospace applications.

Whenever designers/manufacturers need a material that is incredibly strong, fatigue free, and extremely lightweight, they reach for carbon fiber, not titanium, steel, or aluminum.

I have found some new resources to shed some light into the current state of metallurgy in todays frames.

http://www.reynolds-cycle.com/internet/english/tech/tech.htm
the above site has comparitive information on the reynolds tubing.
check out the 6\4 titanium tubing's stiffness and strength on the second table. It also seems that aluminum is kicking some butt!

http://www.columbustubi.com/english/saperne/index.htm
This second site is some of colombus's announcements, if you look down by the bottom, aluminum apparently is growing much stronger in their labs as well.

I am getting sidetracked from my chores now, I just found a manufacturer called strong frames, though, they don't list the materials used beyond steel,ti,alum ect.. I am waiting back for some more information on Reynolds carbon fiber forks, I found a page on www.reynoldscomposite.com (approx address) that lists the tests the do on the fork, there is a repetitive stress test they do, and so I am curious if that would infer a fatigue life. Anyway, I am sure carbon is fine and dandy, but, I need to re-evaluate my thoughts on aluminum.

Oh I missed part of your response, the parts about having one of the worlds best ti builders build your bike. What kind of ti was it? If we are going to compare these materials we need to compare them along a standard of quality. The 6\4 ti is as stiff as the stiffest aluminum and much stronger. I cannot except the argument therefore on your passionately personal experiance X years ago using X titanium. What kind of metal was your carbon frame joined with? aluminium? The point about how many track bikes you see made from titanium.. how many people have the money for a titanium track bike or a carbon track bike for that matter? I see quite a few steel ones =) I suppose ultra high end track racing is all about weight reduction as well, and until recently aluminum and carbon fiber have always been the lightest. I cannot find density information on carbon fiber though, so I don't know how to compare. Now the "steel is the heaviest metal" part, well that is true perhaps, however there are steels now that weight less than aluminum alloys. Anyway, weight has never been a serious enough consideration, a pound...? who cares? do you have an enema before each race? I am sure you could drop a pound or two perhaps more with the tenacity and oversight you attacked metal =) the enema option would probably save you money as well... =) I am going to enjoy my next competition with a clean butt and a comfy inexpensive steel bike. You can't say steel is not a good frame material, there are still many benefits of steel frames. Especially for the 5 billion of us who cannot afford a carbon fiber frame or the best custom titanium frame in the world. I will be content with my steel until it fails me, and that will not be in my lifetime. What you failed to see is the concensus of our debate, is that all materials have their strengths, I have no doubt carbon fiber is wonderful is a lot of cutting edge technology areas. Our debate is common applications of bicycles and the advantages and drawbacks of materials used. I don't know why I just spent so much time arguing the weights of materials...
Jacob

"accept" not "except" above

I've had two carbon frames for a couple of years now- Trek Y22 MTB and YFoil 77 road bike - no problems at all with either. Some of the early carbon fiber frames were prone to breaking, but this was more frame design and unfamiliarity with carbon on the part of the manufacturer than any inherint weakness in CF itself.

Sun damage? I've never heard of this being a factor. There are any number of premium CF components on the market - Cinelli Ram bars, Campy (and others) seatposts, Zipp wheels - that are made from unpainted CF. I tend to think that these premium companies would be painting their equipment if sun fatigued CF. My Y22 has a clearcoat, no paint, and so far no indication that sun is affecting it. Looks really cool, too.

More comfortable? Hard to say - my Foil road bike is very stiff, though the Vector Pro wheels are probaby a contributing factor. Even though it's a beam frame, the parts that aren't protected by the beam (hands and feet) get a full dose of road vibration. My partner's steel framed LeMond rides much smoother, though he can't touch me in a downhill sprint, and normally I'd say he was a stronger cyclist than I am.

One weakness of CF is puncture damage. If you crash and the frame hits something sharp, the CF can crack, in which case you toss the frame. OTOH, how many people do you know that continue to ride an aluminum frame after it got a serious dent? Simple scratches in the paint or topcoat are not a problem.

I've lost count of the number of times I've cracked up on my Y22, and so far the frame remains undamaged.

Give them all a try and see what you think. In all fairness, frame geometry and component selection will have a greater impact on performance and comfort than frame material.

Good points JohnO,

I found this article while searching for prices on the Y Foil
http://www.cybercyclery.com/Members/rich/1043169507/1043160142/news_view

Basically, if you have a 99 Y Foil, there is a recall on the stem sold with it.

Enjoy your riding.
Jacob

Quoted post said:

Originally posted by J-MAT
cpalomo:

Carbon fiber does not have a life expectancy.

Eventually, all metal frames will fail if used long enough due to the finite life cycle all metals have. Your old Pinarello has tons of cumulative stress worked into the metal. Time for a replacement for sure.

The only way carbon can fail is with a catastrophic load at which point the tubes break completely. Don't worry about that happening. Whatever stress you could give to break a tube, a metal frame would fail first, then carbon.

Carbon fiber is the strongest frame material you can buy. The metal parts glued into all carbon frames are the weak links you have to worry about.

Modern carbon frames are highly durable, more than any other frame you can buy.

Trek frames are very good and they will take care of you if there ever is a problem. They were good before, but in the last few years have improved even more. 5200's/5500's are excellent frames!!!

Enjoy your new bike!!!

As a mech. engineering student, I can categorically say that all structures may fail at any point due to material defects. Although many failures of Carbon-fibre are described as sudden and catastrophic this is still due to cyclic loading (fatigue), the catastrophic sudden bit is just cos the initial stages are not detectable.
The main factors in determing the life of a frame are how well it is built (ie are there defects in the material increasing local stresses) and how well is the frame designed (ie is there material where it needs to be).
The best thing to do, even if there is a lifetime warranty, is to inspect the frame every now and again for cracks-but don't make the mistake with the trek carbon fibre frames of thinking that the joints in the tubing are cracks!
Carbon fibre is very nice though...
enjoy yer bike!

First, because I know someone is waiting with baited breath, I will retract my 24,000 mile statement.. Remeber I said I would check on that... We I musta been mixing half-and-half in the coffee at the local bagel shoppe <in my bike shorts which is a no-no... Oh wait that is another thread... Seems when I had the cream-cheese in my ears I converted the conversation from 24,000 miles left on the frame from... I'm about to go a distance approaching the circumference of the earh on my carbon bike...

Ah well...

As for the way this thread is going I see someone (same someone) showing an extreme partiality to carbon...

But at the same time while it is stated that carbon never fails they point out that another weakness of carbon, other than someone's bad design, is that where there is metal on metal you can experience a different type of failure... The cited example is the BB shell coming un-glued from the frame...

OK then let me add to that... What about drop outs? Hmmm... What about seat-post binder bolt contact areas? Hmmm...

And to make matters worse, this person has an adverse reaction to aluminum <but then so do I> to which we find that most of these pieces that are glued or run through the inside like a skeleton... Well these pieces are Aluminium so they are also going to cause the frame to fail... Sure it's not the carbon that fails but I think if a for drop out of aluminium cracks off and the front wheel pops out then you may find yourself picking up pieces of your carbon frame <after you pick up the pieces of yourself>...

Anyway to move on... Different materials for different jobs...

Examples:
Steel... Good cheap bikes... Commuter bikes... Touring bikes
Al... Good cheap bikes and can handle moisture better... But has a fixed cycle life.... Also has a harsher ride than steel... Commuter bikes.. Often used for ATBs.
Ti... Like steel for the ride, impervious to rusting or cycle failure <like steel> Good for high end bikes (because it is $$)
Carbon... Same as Ti but can be special molded into wierd forms to which could produce better ride... Requires special care with greases... Also contact areas must be metal so there are some glue-point issues.

Now let's take a different look...

Carbon Fading in sunlight...

1) My commuter bike is a cheap mountain bike made of Al because I don't care...

I live in South Florida where we get tons of sunlight. Saddles left out in the sun while I'm inside at work will fade and rot in no time. I use a garbage bag to cover the saddle and sack to make them last longer. The paint on the frame is faded on one side (the side that faces the sun) and the tires tend to rot off <on one side, you guessed it the side the sun is on>... Same for brake cables... The housings either rot away or rust from inside out <don't forget it rains in Fla and rains HARD>. Baking water into the frame <steel bikes have fun with this!>...

Now I know most of us don't leave our $3000 carbon and Ti bikes out on a bike rack 5 days a week in front of the office in the baking sun... It just aint right and it just aint smart...

Of course that is only if you scratch into the fibers as the epoxy could be UV resistive <but resistive indicates a lifetime>. This came from a check of the use of carbon fiber in, not aerospace, but aero-planes... "Sunlight can damage glass and carbon fiber cloth and resins used in composite-construction airplanes." So if you left your bike outside instead of inside the hanger for countless weeks/months on the tarmac of a shadless runway... Well... You get the idea...

Also I know someone with a Klein ATB... On the maiden voyage he spilled and dinged the frame on a rock. Yep it looks like someone took an oversized metal punch and knocked a dimple into the frame... No sever damage. paint is even intact. Assume there is some reduce in the life of the Al but not enough to toss the frame...

Nuf is Nuf. I will use steel and Al for frames where this makes sense, Ti is my choice because I like the feel of my Litespeed frame. My #1 riding buddy loves his Trek 5500 and I'm not knocking him for it... High end frames are exotic and so you can do or buy what you want... Be positive and friendly and remember that most of what we say here is talk and therefore laced with opinions...

Time to move on and ride those frames... None of them last for a lifetime... Well esp if you keep them indoors and keep typing...

Going to go take some more life off of my bike <and add some to my life!>...

See ya!

Ti... Like steel for the ride, impervious to rusting or cycle failure <like steel> Good for high end bikes (because it is $$)<<

My Merlin (Spectrum) broke in two places with about 40,000 miles on the frame, so don't tell me Ti won't break. On the other hand it was an early (1991) model with straight guage Ti tubing. I'm hoping my 10 year old Ibis (which sat in my garage for 5 years and only has 25K miles or so on it) will last me another 5 seasons (25K miles at my current rate).

Ti is mushy? Maybe that's why pros don't ride it much (they all ride carbon/aluminum in Europe). But I'm not putting pro wattage into my bottom bracket. I'm a 47 year old club rider/sometime racer. My Ibis is plenty stiff for me and sucks up road shock beautifully. Best damn bike ever built, lighter than a Litespeed Vortex and infinitely cooler. By the way, @ 170-180lbs I'm hardly a lightweight and my Ibis Ti is perfect for me in every respect.

i have read a fantastic theory postulated, that if a frame lasts a certain number of fatigue cycles under a given stress it will never fail. maybe that treviso will outlast us all.
unless we ride much more than post...

[quote="J-MAT"]cpalomo:

Carbon fiber does not have a life expectancy.

cycle all metals have. Your old Pinarello has tons of cumulative stress worked into the metal. Time for a replacement for sure.

[quote="Hypnospin"]i have read a fantastic theory postulated, that if a frame lasts a certain number of fatigue cycles under a given stress it will never fail. maybe that treviso will outlast us all.
unless we ride much more than post...

J-MAT said:

cpalomo:

Carbon fiber does not have a life expectancy.

cycle all metals have. Your old Pinarello has tons of cumulative stress worked into the metal. Time for a replacement for sure.

Mr_Potatohead said:

steel has what is called a fatigue endurance limit. Meaning there is a stress level at which or below the fatigue life is infinite.

Aluminum does not have an endurance limit. A low stress level can still induce fatigue given enough cycles.

But a heavy-walled steel bike, with infinite fatigue life, isn't what most of us ride these days. My 1973 Raleigh, built with the thick gauge 531 of the day, might last a lifetime, but I'll pass on the weight and harsh ride in favor of something modern.

The local custom builder does a lot of race and TT frames. He offers the usual "lifetime" warranty on defects, plus a specific 3 or 5 year warranty on fatigue failures. While most of his steel frames have the 5 year fatigue warranty, the thinnest steel tubesets, (eg, Ultrafoco) come with the same 3 year warranty as his AL & CF.

I have one of his AL/CF frames. My goal is to ride it long and hard enough to break it in the next 10 years/50,000 miles, and have it put on display in his "Hall of Fame" of broken frames. Will be great bragging rights if I can ever manage it.