lookinUp

I've got an opportunity to purchase a Trek 2250 - probably 10+ years old. Wondering if carbon fiber bikes that old are still ok to ride. I haven't seen it yet and know to look for cracks and chips, but just need some advice on whether CF will hold up when it's that old.

ericm979

Sure. It's made from carbon fibers and epoxy. As long as they are protected from UV (which the paint or clear coat does) those materials don't degrade.

Check the frame carefully for cracks and make sure that the BB shell is still firmly bonded in the frame. Sometimes they come loose. Wiggle all the "braze ons" to make sure they are still firmly in place.

Treks are serviceable but nothing special, so if it's questionable, walk away.

ModeratedUser150120149

Like any other material if it is good condition it will be fine. If you don't know what good condition is take it to someone who does; even if it costs a couple dollars. After all, if you wre buying a car and didn't know how to judge it you'd pay someone to give you advise. No difference.

curbtender

If it wasn't abused it should be fine. https://www.trekbikes.com/pdf/carbon_...Care_Flyer.pdf

stapfam

I have had a C.F. bike for 5 years now and it has lasted well. The material will last and it will show any hard use just like any other material. The worrying thing about c.F. is that IF it has taken a hard knock- it may not show that damage immediately but within not so many miles it will become apparant. Knocks may chip the Gelcoat or spray finish to the bike but providing the Laminated material beneath that is not damaged- then it should be OK. The joints of the frame will show a "Crack" if they have been damaged but this would be rare unless it is where another material has been bonded in like C.F. stays onto an alloy frame or araound the bottom bracket. This is probably where flexing has taken place on the C.F. to the more rigid frame material and the Gel coat could show a crack. This is more prominent on a dirty bike that has those joints wiped clean and not polished so probably not serious if it is just a fine line showing but don't touch it if it is prominent. I know of two bikes that have this line just showing and they have been fine for several years. You can check this out by putting weight on the bike and seeing if those lines get wider. If they do don't touch it.

But a test ride is in order before any purchase. C.F. is not for everyone despite being the "Wonder" material but a test ride will show up any faults in the frame. I have no idea if C.F. goes off like other materials but if there is damage to the frame taht you haven't spotted- then you would feel it on the ride or spot it on the visual frame check you do after a test ride.

I used to be a Fibre glass laminator making boats and Boats made 50 years ago are still good and they do take a lot of knocks and Stress on the type I was working on. Admittedly Bike frames are a lot thinner but Trek would know where strength is needed so will not be as fragile as you may think.

But are you buying it privately or from a dealer? Do you know the history of it? is there any warranty offered? Those points and your own check and test ride should tell you if it is worth buying.

alcanoe

About 6 months ago, my son bought a 15 year old CF Trek. I wanted it, but my son needed a bike, so I let him have it. This particular bike was very little used and was in unbelievable condition.

He's ridden it a lot and so far so good. As stepfam mentioned, even FG boats last forever and they are held together with polyester resin. CF is held together with epoxy which is far tougher. It all depends how well the frame was designed to with stand the stresses and possibly how much it's been used.

I've been told by some amateur road racers that after some number of years, the frame gets more flexible and they get a new frame. How accurate that observation is I don't know. However, I've seen that happen to FG boats and our FG and Kevlar canoes due to high stresses over time.

Al

Wogster

The problem with CF is that there are some dishonest sellers out there. One problem with Trek, from what I understand is that they warranty their CF frames for life, but you need to pay the dealer to transfer the components over to the new frame. This can cost a couple hundred bucks, and the guy figures he can sell the old one for a good price, put $400 into it and get a whole new bicycle. So they fix the old bike up so that it looks good, and sell it. They recommend replacing the frame because the only way to sometimes see damage is to strip it and then used industrial Xray to see what is happening under the surface. This costs more then to simply replace the frame.

CF that fails because it's damaged, tends to suffer a cascade failure, some of the fibres are broken and that reduces the over all strength, which puts stress on the remaining fibres, which causes some of them to break, which puts more stress on the remaining fibres, which causes some of them to break, and eventually they all break and while the epoxy is strong stuff, it's no where near strong enough. From the beginning of the failure until complete failure can be under a second.

Now, if you know the person who has the bike and know it's history and that it's never been crashed, you should be okay, if you don't know the person who has it, and whether it's been crashed, then your better to avoid it.

NOS88

My experience (have had three CF frames fail and the parts put on the new frame) is that a few hundred dollars is way too much. I've never been charge more than $100 and that was for the first two parts transfers. The third one was free.

To the OP, the CF will last well beyond ten years if protected. Like the others have said have it checked for hidden cracks and possible places where it has started to delaminate.

ModeratedUser150120149

Underlined for reference, not because I in any way agree.


These are true for most materials, not just carbon fibre. Corrosion, stress cracks, etc plague aluminium, steel and other structural materials. On the other hand, from experience, carbon fibre tends not to hide significant structural faults.

The underlined is true UNLESS you or someone you trust can properly evaluate the machine. Carbon fibre is not some miracle material. Nor, is is some weird, mysterious spirit incarnation just waiting to spring some surprise on the unsuspecting like a horror movie monster in the bushes.

Don't need to do anything special when buying this machine you shouldn't do with any other. In short, if it looks good and works correctly it is good to go. If it has a readily apparent fault think about it. If you can't properly evaluate the machine hire someone you trust to do so. If it looks bad, you get bad vibes from the owner, it doesn't work correctly, etc. move on to something else. Nothing mysterious about this process as it applies to just about anything a person buys.

CraigB

I don't know if Trek has changed their policy, but about 10 years ago my Trek aluminum frame cracked at the drive side dropout, and they not only paid for a new frame, but reimbursed the shop to tear the old one down and rebuild the new one. The only thing I was out was the cost of new handlebar tape.

lookinUp

Thanks for all the good info. Unfortunately, the bike sold before I ever got a chance to see it. Guess my n+1 will have to wait.

Wogster

The issue is that metal frames, whether it's steel, aluminum or even Ti will elastically deform long before it will break. CF can look perfectly fine, even though it's damaged to the point where it can fail. If this was not the case, do you seriously think manufacturers would replace crashed frames, without inspecting them first.

ModeratedUser150120149

You say carbon fibre can look fine up to the time it fails. I suppose you mean to the naked eye. The other materials can do the same. They can do that in many different applications including bicycles. That is why, regardless of the application, it pays to closely inspect the machine before use. Using a material in a bicycle is no different than using it in any other suitable application. There is no mystery about it. What is a mystery is why all these myths about carbon fibre seem to persist in the face of factual experience.

As far as a manufacturer's business practices are concerned; I suppose that is their business. However, IF it is true that they do not routinely inspect a warranty return frame before replacing it that is most likely a business decision, not an engineering decision.

stapfam

Keep looking.

Main point about a secondhand bike is that it is set up for the previous owner. Components that may have been changed and the fit of the bike. Component changes are usually down to upgrades being required when parts wear out such as Derraillers and Casettes. Not that you would notice a cassette change but if you are expecting a 12/27 cassette and get an 11/21- it can come as a shock.

Fit of the bike- providing it is the right size- can be modified but make certain the bike is the right size in the first place.