Crack in carbon frame ?

davmol

Hi all. I am buying a bike and saw what appears to be a line in it. It's at the bottom of the saddle post. Can anyone offer advice of opinions on this ?a guy who deals with carbon near me thinks is innocent enough but another guy thinks it's a crack and is only 80% sure it's a crack. Any ideas?[/php]

Eamonnator

That looks like a crack to me, furthermore, it's at a place, that comes under a lot of stress.
Even if it's only the paint, that is cracked, you have to ask yourself, what stress caused the paint to crack.
I certainly would not take a chance, and buy that bike.
Equally, I would not take a chance and ride that bike.

davmol

Eamonnator wrote: »

That looks like a crack to me, furthermore, it's at a place, that comes under a lot of stress.
Even if it's only the paint, that is cracked, you have to ask yourself, what stress caused the paint to crack.
I certainly would not take a chance, and buy that bike.
Equally, I would not take a chance and ride that bike.

What kind of outcome would you foresee with it?do you think riding it could be dangerous?

Eamonnator

Worst case scenario, you're riding along, frame breaks, suddenly you're sitting on the back wheel. In fact, thats not the worst case scenario.
Best case, it's only the paint, thats cracked, and there's no damage to the carbon.
And you've got yourself a bargain.
And there are a lot of thing, in between, that could happen.
But, why take the chance. Buy something else.

Daroxtar

davmol wrote: »

What kind of outcome would you foresee with it?

Ever watch Love/Hate? You know Fran?

Eamonnator

Daroxtar wrote: »

Ever watch Love/Hate? You know Fran?

Yeah, that too.

braddun

I would not buy

Cee-Jay-Cee

There is no real way of knowing without stripping back the paint and examining the carbon fibre itself.

It could be just the paint that's cracked from the flex of the seat post through the seat tube/top tube junction but it's impossible to say.

What bike is it?

davmol

Cee-Jay-Cee wrote: »

There is no real way of knowing without stripping back the paint and examining the carbon fibre itself.

It could be just the paint that's cracked from the flex of the seat post through the seat tube/top tube junction but it's impossible to say.

What bike is it?

It's a fuji super lite carbon frame. CAn u definitely tell if it's the carbon that's cracked by peeling back the paint ?i heard of an x-Ray being needed and thermal imaging?? A Guy I spoke to said he could repair the carbon. A guy in carbontec. Any thoughts??

carltonleon

I had a similar looking crack across my carbon fork. Brought it to my LBS just thinking it was the paint that had cracked. To my amazement it ended up that the manufacturers replaced the fork even though the bike was 3 years old. Don't take a chance.

iwillhtfu

davmol wrote: »

CAn u definitely tell if it's the carbon that's cracked by peeling back the paint ?i heard of an x-Ray being needed and thermal imaging?? A Guy I spoke to said he could repair the carbon. A guy in carbontec. Any thoughts??

No it can't be 100% determined one way or the other without some form of scan be it thermal or otherwise.

You'll always find someone who can do a repair on carbon frames. It might be worth a shot but then again how much would it cost for a new set of nashers if it does let go? Although from the look of where the damage is it would probably be a gradual collapse as opposed to the one mentioned above. A crack in a fork I'd never have repaired.

Depending on price I'd probably give it a go and see if there's any sign of the crack spreading.

zurbfoundation

doubt it will fail catastrophically if it does fail. Depends on the price I guess

sherlok

it's a gamble, but because it's an irregular crack, personally i'd be more willing to take a chance as it may just be in the paint. Also, where it is on the seatpost means the stakes aren't quite as high compared to a similar crack on fork. Something like the crack that carltonleon posted looks a lot more sinister to me, as it's a straight line.

ultimately it's up to you. if it does turn out to be a crack it really comes down to whether it's worthwhile to repair it, or you just put it down to experience.

Pinch Flat

Run (or cycle) a mile

Brian?

If you're getting it cheap, buy it and repair.

davmol

Brian? wrote: »

If you're getting it cheap, buy it and repair.

I'm getting it for 900€. It has carbon handle bars and full set of ultegra gearset. Seeing a guy tomoro regarding checking the cracks to see if they are actually cracks or paint it some other issue. Many thanks fr the advice so far

Zynks

I found something very similar described as "Small fracture near the top tube, seat tube, down tube junction. The cause of this was because the original seat tube was simply too short, despite complying to the “min. extension” warning on the tube."


Source: http://www.randorichard.com/carbon-bike-durability

Eamonnator

davmol wrote: »

I'm getting it for 900€. It has carbon handle bars and full set of ultegra gearset. Seeing a guy tomoro regarding checking the cracks to see if they are actually cracks or paint it some other issue. Many thanks fr the advice so far

I would be taking my 900 Euro elsewhere.

Cee-Jay-Cee

I wouldn't psy anymore than €400 for that bike as I'd effectively be writing off the frame and buying it for the groupset only.

iwillhtfu

Yeah op as above at €900 I'd be going elsewhere.

The reason for the crack above makes perfect sense.

macnab

Just a guess, but I'd say the seat post was too short for the rider. You need at least 3 diameters (100mm is safe) below the clamp.
I have seen an almost identical crack on a small sized alloy frame, which was being used by a large powerful rider.
It is repairable but I wouldn't buy it for more than €100 as a bare frame.

carltonleon

For €900 i would definitely stay away. For €1599, you can get the full Ultegra on the 2015 Cube Agree Race. Save up the extra and get a brand new bike and if you can get the Bike to Work scheme, then it would work out at about €1000 net, at least that is what I would do.

http://www.chainreactioncycles.com/ie/en/cube-agree-gtc-race-compact-road-bike-2015/rp-prod127967

Koobcam

It's probably the paint, but at the very least I'd get it checked out by a professional before buying. If it's a crack in the carbon, you should be able to feel it, like a slight difference in height between the two affected pieces. Press down hard on the affected area and see if there is any flex. Probably though you might be better off thinking about a different frame, just for peace of mind.

jmoore50

Its just the paint.
I had the same issue with a Fuji Frame last year in exactly that same place.
Went back to the Distributor and they assured me it was just a paint issue.
Sent pictures and said if I removed the paint it would show it isn't cracked. I did that and it wasnt.

Here was their response:

thanks for choosing a FUJI.
We regret that you have problems with your bike but we are sure that we can convince you that your bike is safe and that the frame is not cracked.
Paint cracks on carbon frames are not something unusual. Carbon is a material that is flexible and strong. The flexibility of the carbon is the reason for the paint cracks. The clear coat does harden over the time and will show small cracks because of the frame flex.
If these clear coat cracks happen on white or light color prime coat, you will see them as some dirt will fill the paint crack.

See attached some photos of a carbon frame with paint cracks. I hope these will convince you, that also the crack on your frame is a paint crack and not a carbon failure.
Our warranty manager Andreas has reviewed the photos of your frame and he believes that your frame does not have a carbon failure based on his experience.

should you have any more questions do not hesitate to aks us again.

with kind regards


Armin van Hoogstraten |
FUJI, KESTREL, SE BIKES, BREEZER, OVAL
Advanced Sports GmbH | Bergstrasse 16 | 73557 Mutlangen | Germany
Phone +49.7171.7799022 | Fax +49.7171.7799010
mobile +49.171.9322555
fujibikes.com | kestrelbicycles.com | sebikes.com | breezerbikes.com

Cee-Jay-Cee

jmoore50 wrote: »

Its just the paint.
I had the same issue with a Fuji Frame last year in exactly that same place.
Went back to the Distributor and they assured me it was just a paint issue.
Sent pictures and said if I removed the paint it would show it isn't cracked. I did that and it wasnt.

Here was their response:

thanks for choosing a FUJI.
We regret that you have problems with your bike but we are sure that we can convince you that your bike is safe and that the frame is not cracked.
Paint cracks on carbon frames are not something unusual. Carbon is a material that is flexible and strong. The flexibility of the carbon is the reason for the paint cracks. The clear coat does harden over the time and will show small cracks because of the frame flex.
If these clear coat cracks happen on white or light color prime coat, you will see them as some dirt will fill the paint crack.

See attached some photos of a carbon frame with paint cracks. I hope these will convince you, that also the crack on your frame is a paint crack and not a carbon failure.
Our warranty manager Andreas has reviewed the photos of your frame and he believes that your frame does not have a carbon failure based on his experience.

should you have any more questions do not hesitate to aks us again.

with kind regards


Armin van Hoogstraten |
FUJI, KESTREL, SE BIKES, BREEZER, OVAL
Advanced Sports GmbH | Bergstrasse 16 | 73557 Mutlangen | Germany
Phone +49.7171.7799022 | Fax +49.7171.7799010
mobile +49.171.9322555
fujibikes.com | kestrelbicycles.com | sebikes.com | breezerbikes.com

So the warranty manager only reviewed the photos of the bike/damage and not the actual frame itself! I wouldn't be accepting that explanation from anyone! I don't care how experienced someone may be in their field, a review of a photo (no matter how HD the photo is) does not allow a proper examination and therefore diagnosis of the problem.

monkeyslayer

That response from Fuji is disgraceful, how would they know its just paint cracks from looking at a picture? and why should their paint job flaking away be acceptable anyway?

I'd a similar problem with a focus frame a few years back and they took it back and replaced it immediately with a new one, they just weren't going to take a chance that the frame wasn't going to fail. I'd imagine most manufacturers would be the same.

OP, I wouldn't buy that bike, even if its fine just that little bit of doubt will be enough to ruin your enjoyment of a pretty pricey purchase. There's
some sales coming in the next few weeks, maybe wait and see if you could pick up a bargain in them and a get a brand new bike with a warranty.

Eamonnator

You would have thought, that by now, somebody would have invented a paint, that would flex with the carbon.

Now, as it happens @jmoore50, I think, I have come up with just such a process.
If you send me @5,000, I guarantee a 100% return on your money. Do not hesitate.

davmol

jmoore50 wrote: »

Its just the paint.
I had the same issue with a Fuji Frame last year in exactly that same place.
Went back to the Distributor and they assured me it was just a paint issue.
Sent pictures and said if I removed the paint it would show it isn't cracked. I did that and it wasnt.

Here was their response:

thanks for choosing a FUJI.
We regret that you have problems with your bike but we are sure that we can convince you that your bike is safe and that the frame is not cracked.
Paint cracks on carbon frames are not something unusual. Carbon is a material that is flexible and strong. The flexibility of the carbon is the reason for the paint cracks. The clear coat does harden over the time and will show small cracks because of the frame flex.
If these clear coat cracks happen on white or light color prime coat, you will see them as some dirt will fill the paint crack.

See attached some photos of a carbon frame with paint cracks. I hope these will convince you, that also the crack on your frame is a paint crack and not a carbon failure.
Our warranty manager Andreas has reviewed the photos of your frame and he believes that your frame does not have a carbon failure based on his experience.

should you have any more questions do not hesitate to aks us again.

with kind regards


Armin van Hoogstraten |
FUJI, KESTREL, SE BIKES, BREEZER, OVAL
Advanced Sports GmbH | Bergstrasse 16 | 73557 Mutlangen | Germany
Phone +49.7171.7799022 | Fax +49.7171.7799010
mobile +49.171.9322555
fujibikes.com | kestrelbicycles.com | sebikes.com | breezerbikes.com

The more i hear the more i think ill steer clear.
Just out of interest jmoore50,is the bike still running/any further cracks?
Excuse the noob question but should paint not crack anyway,is there a paint that will flex with the frame?

Cee-Jay-Cee

davmol wrote: »

The more i hear the more i think ill steer clear.
Just out of interest jmoore50,is the bike still running/any further cracks?
Excuse the noob question but should paint not crack anyway,is there a paint that will flex with the frame?

Vinyl paint is flexible but it's also heavy and probably expensive and I'm guessing that's the reason it's not used.

jmoore50

Yes it was absolutely perfect, trained, commuted and raced on it and probably put about 10,000km on it since I first saw the crack. Used it on Turbo regularly and no other issues. It was stolen back in November so not sure how the 'new owner' is getting on with it now!

Alek

I dont buy the Fuji guy explanation at all.

Carbon or not, frames do not twist, bend or elongate at joints.... at least not to a degree that would crack the paint.

davmol

Alek wrote: »

I dont buy the Fuji guy explanation at all.

Carbon or not, frames do not twist, bend or elongate at joints.... at least not to a degree that would crack the paint.

Doesnt carbon have an element of flexibility?

Where the seat joint is ,iassumed it was from the previous rider who is a big lad putting strain on the frame and the flexing of the carbon subsequently cracking the paint?
Just my assumption from very limited knowledge.

Alek

Every material is flexible to some extent. Bicycle frames are engineered to flex in a controlled manner, in specific areas and versus adequate forces. This should however not be happening at rigid joints.

disco1

Walk away from it...it's cracked