Mountain Biking - Carbon Fiber Bikes

What is the lifespan of carbon fiber bike. I am looking at buying a used 2000 Trek 9800 OCLV with a few paint chips and scraps. I am not that hardcore of a biker. I just ride my bike around campus and do some occasional weekend mountain biking. I this kind of a frame going to hold up for me for 5 or 6 years to come?

It's important to see YOUR specs too e.g. your weight height etc. and more specifics on your riding style. Any drops, jumps hucks or anything like that?

Why would you buy a carbon fiber bike for riding around campus? Its nice, its stiff, its light, but for riding acound campus and "occasional" weekend trails your kidding yourself. But besides that, yes it will hold up. I do not own a full carbon bike, but a friend of mine owns a full carbon frame (road so it has the fork too) and loves it, they are actually using carbon on bridges so yes it will hold up.

occasional weekend biking to a new comer can be very extreme or very moderate. better safe than sorry so we'll see how extreme it is first

Duh, cause.....

carbons pimp factor > anything else

its a hell of a lot of cash to pay for a pimp factor. Support the economy

What is the lifespan of carbon fiber bike. I am looking at buying a used 2000 Trek 9800 OCLV with a few paint chips and scraps.
I don't even recommend buying used carbon ROAD bikes. I damn sure ain't going to recommend buying a four year old carbon MTB (that's most likely been ridden to hell and back) with chips and scratches. In my opinion carbon is a one owner deal - you can never be sure of what you're getting and because you're not the original owner you have no recourse should something go wrong.

I don't even recommend buying used carbon ROAD bikes. I damn sure ain't going to recommend buying a four year old carbon MTB (that's most likely been ridden to hell and back) with chips and scratches. In my opinion carbon is a one owner deal - you can never be sure of what you're getting and because you're not the original owner you have no recourse should something go wrong.

While I love my carbon bikes and I do believe in the material, CF also comes with it certain care requirements. I totally agree with Raiyn on this. The biggest problem with CF is that damage is not immediately obvious. There are ways to discover it though. However, why take the chance?

Again, I agree with Raiyn and Khuon.

The problem with carbon is that when it fails, it's usually sudden and explosive. It's not like steel or even aluminum that will deform first. When it breaks, it SNAPS!

Plus, although carbon is improving, I think it's a "Special Niche" market. It's more of a XC Racer Boy type choice.

Indeed, carbon is the stiffest, strongest and lightest stuff but if it gets a chip its strength is reduced greatly. It still has a way to go before i will ride a carbon frame.

Indeed, carbon is the stiffest, strongest and lightest stuff but if it gets a chip its strength is reduced greatly. It still has a way to go before i will ride a carbon frame.

I don't fear carbon but I do fear not knowing the history. A CF bike made by a reputable builder and taken care of properly will last as long if not longer than similar bikes of other materials. While, I can check out and research the build methodology of the frame and component manufacturer, I cannot do the same for the care unless I'm the original and only owner. I feel that CF as a family of materials has its greatest strength in its versatility and not necessarily in its lightness or stiffness because again, it's the versatility that will allow a builder to tune those other properties to a much higher degree than with any other material. However, because in engineering a CF structure, one is essentially producing the material at the same time as construction and assembly, there are greater potentials for screwing up. In short, CF is very easy to screw up and the more exotic the CF such as the emerging nanotube stuff, the more potentials exist for QC problems to arise. As for things like "runtime" durability and notch-sensitivity, CF has come a long way and continues to improve. All materials have distinct failure modes and a good bike designer will be able to exploit the advantages of a material while mitagating the weaknesses.

What is the lifespan of carbon fiber bike. I am looking at buying a used 2000 Trek 9800 OCLV with a few paint chips and scraps. I am not that hardcore of a biker. I just ride my bike around campus and do some occasional weekend mountain biking. I this kind of a frame going to hold up for me for 5 or 6 years to come?

Trek carbon frames have a lifetime warranty. If you know the owner well, get the recepit off him and you should be OK. But why a carbon frame just to ride around campus?? If you dont have a good place to lock it up, chances are, your bike will be gone in two weeks....

I would always use my beater if I rode my bike to school.....

Indeed you get a reputable company like easton products or Trek, giant etc. your carbon will be high grade and serve you well. I doubt i willl ever buy a full carbon frame in the near future, i feel like with my AL frames i can do whatever i want with it, not hte feeling with carbon. So in the mean time i believe carbon has some more advancements to be made.

Scratches and chips on a carbon fibre frame/fork/component are like a tear along this line mark on forms. Once there is damage the part is weakend radically.

Scratches and chips on a carbon fibre frame/fork/component are like a tear along this line mark on forms. Once there is damage the part is weakend radically.

Really? I have several scratches and a few chips on my CF frame. To think that this will radially weaken the frame is absurd. Do you really think Trek, Giant, Scott, etc will design and sell a CF frame that weakens after a few chips? What mountain bike in the world can get away with no scratches or chips?

Having said that, I would also stay away from a used CF mountain bike.

Its the natur of carbon, trek or giant can't change carbons properties, when you buy a product you assume all responsibilities. I see more carbon bikes for road use, than mtb use. If i was in the market to get a frame beside steel or al for mtb i would use titanium, that is for the entire frame though. FOr components i like carbon :)

Its the natur of carbon, trek or giant can't change carbons properties, when you buy a product you assume all responsibilities.

Yes and no. A scratch or chip if deep enough can compromise the integrity of a particular laminate layer. This may or may not have detrimental impact on the entire structure. In short, it depends. Many road frames are made up of over five layers of carbon fiber. Many MTB frames are made of ten or more (upwards of 20 to 30 in some high-stress sections such as the head-tube). Also, it depends on the nature of the layer. A single unidirectional prepreg reacts differently in both load bearing and impact than a multidirectional. Generally speaking a twill weave or for high-impact resistance, chopped-strand mat is used for the outer layer for aesthetics and resiliency purposes such as in MTB applications. Chips and nicks in this layer usually is considered superficial and may have no structural impact whatsoever.