# carbon frame with hairline crack common



## tjjm36m3

From one of the links in the "daily carbon failure" thread, I noticed a picture of a carbon Time frame with what is described as a hairline crack. I had seen similar "cracks" like this before but they were labeled as crack in the paint instead, not in the carbon layup. I noticed a similar crack in identical length and detail on my BB as the picture below six months ago, but I been riding it since then with no problems mixed with some pretty intense hard sprints. I been thinking mine as a paint flaw otherwise my frame would have catastrophically explored sometime in the last six months. My question is this typical of most paint jobs on carbon fiber frames, or I really do a have crack in the layup? 

http://2.bp.blogspot.com/_V54WWNeyyp4/Sztwade3vAI/AAAAAAAACGY/yxrASqYeVV8/s1600-h/May+31+09+001.jpg


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## Oldteen

I have a similar thing on an 06 Cannondale Synapse carbon. I think mine is just paint/clearcoat not in carbon. A while back I cleaned area carefully & marked end of each crack with fine Sharpie. Nothing has changed after much riding, inc. tough century on some bad Midwest chip-seal roads.


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## wayster

*Same here ...*

Just noticed the same issue on my 3 month old Cannondale Synapse Carbon.


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## Clicker7

Guys, I think that is just the gelcoat!


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## dracula

tjjm36m3 said:


> From one of the links in the "daily carbon failure" thread, I noticed a picture of a carbon Time frame with what is described as a hairline crack. I had seen similar "cracks" like this before but they were labeled as crack in the paint instead, not in the carbon layup. I noticed a similar crack in identical length and detail on my BB as the picture below six months ago, but I been riding it since then with no problems mixed with some pretty intense hard sprints. I been thinking mine as a paint flaw otherwise my frame would have catastrophically explored sometime in the last six months. My question is this typical of most paint jobs on carbon fiber frames, or I really do a have crack in the layup?
> 
> http://2.bp.blogspot.com/_V54WWNeyyp4/Sztwade3vAI/AAAAAAAACGY/yxrASqYeVV8/s1600-h/May+31+09+001.jpg


Hairline craks, even though only in the paint, are not common by design. And should never bee seen as such. However, it is fairly common in reality.

I would just slightly and carefully sand the painted area down to check if there are any visible cracks in the carbon structure. 

If you hear a creaking noise on your rides it could mean your frame is compromised and carbon starts delaminating.


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## Blackss06

I saw one on my frame the other day, probably been there for awhile now. 

A lot of people would probably tell you to trash it or break into a doctors office and borrow an x-ray, or else it will spontaneously asplode and you'll die.

But I will be riding mine, keeping a close eye on it to make sure nothing develops out of it, and if it asplodes, it asplodes.


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## Bombaman

Cracks in the paint or gelcoat layer occur mainly a result of a reduced flexibility of the named layers. This can be due to aging (UV exposure). Such cracks should not occur on new bikes because the paint and gelcoat layer should be flexible enough. 

On an older bike it is always good to keep an eye on such cracks. Maybe mark the ends to track changes. One can also clean the cracks and seal them with CA (thin glue).

My old Trek Y11 MTB has a lot of these cracks but as time proved these are only cosmetic flaws.


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## lamazion

Same on my Cannondale Synapse.


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## latman

Bombaman said:


> Cracks in the paint or gelcoat layer occur mainly a result of a reduced flexibility of the named layers. This can be due to aging (UV exposure). Such cracks should not occur on new bikes because the paint and gelcoat layer should be flexible enough.
> 
> On an older bike it is always good to keep an eye on such cracks. Maybe mark the ends to track changes. One can also clean the cracks and seal them with CA (thin glue).
> 
> My old Trek Y11 MTB has a lot of these cracks but as time proved these are only cosmetic flaws.


one way trek differs from lots of brands is its front triangles are made in a few parts(3) and then glued together (the joints are then sanded really smooth) and they often then seem to show cracks in the paint at those joins.


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## Genshammer

*Carbon Repair*

As Bombaman points out, cracks in paint or clearcoat aren't necessarily an indicator that the carbon underneath is cracked. Carbon fiber is designed to flex and move, especially at the lug lines where two tubes overlap and are bonded to each other. Paint and clearcoat are not designed to flex, which results in hairline cracks in the paint.

We most often see these cracks along lug joints, and the resulting crack most typically follows the exact contour of the lug line (IE a straight crack). Cracked carbon hardly ever goes in a dead straight line - it splinters out in different directions.

Cracks in paint are strictly cosmetic. If it is along a lug joint, the crack is straight, and you've never experienced an impact in that area, you're probably fine. But if you still have concern, tap the area with a quarter. Proper tubes "click", cracked tubes "thud". If you feel a thud, sand off the paint in that immediate area to see if the crack indeed penetrates the carbon - but remember, you might be sanding a lug joint. If its a dead straight line in the carbon, it's not a crack!

If you have any other questions, feel free to get more information on our experience and repair process at the site below.

Sincerely,


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## Kuma601

Hard to say, appears like a scratch over a crack. Now if it has grown then it says otherwise.
If it is superficial, using a automotive cleaning type wax will remove the road grime from the surface area. If it doesn't, it is either pretty deep and or a crack.


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## leeDuvy

had the same problem


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## tihsepa

And you guys are ok with this?

Not a carbon fan because of crap like this. Everyone has convinced themselves that a crack , joint movement, settling or whatever is ok.
If that makes you feel better, ok. In my view no way would Cannondale or any other try to convince people that cracking paint, flexing or whatever is ok.


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## wiggy1

12 years riding with similar symptoms around what look like frame lugs (very early carbon frame) and never a problem. LBS had sent the frame back on warranty for the cracks when I was first concerned and the frame was inspected, repainted and returned. The cracks showed up again and I didn't worry. That was over 10 years ago and I am still riding the bike. I think it will be fine for you.


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## Porca

If I found this on my bike I would take it back to the store where it was bought and get it inspected and warrantied just to be sure that it was the paint and not carbon lay up


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## terbennett

What's with the Synapse having these issues? Two of my buddies have had to have their frames replaced due to cracks that looked like clearcoat cracks untilthe LBS saw them.


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## tihsepa

My feeling is that some of these uber-light frames are made for the pros and the pros only. Normal people are using them well beyond their intended lifespan and they fail.


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## terbennett

tihsepa said:


> My feeling is that some of these uber-light frames are made for the pros and the pros only. Normal people are using them well beyond their intended lifespan and they fail.


Hmmmmm. I think you have a point there. Even Specialized has put a 250 lbs. weight limit on their carbon frames. I wouldn't doubt that others will follow suit soon.


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## svard75

In a recent article in MBAction they rated life spans of different material Mountain Bikes and associated parts. Carbon frames were given a 3 year life limit *as a Mountain Bike*. But then again take this info with a hand full of salt because they gave aluminum 4 years and cromo 7!

But anyway that crack just looks like a paint crack as everyone mentioned. If the frame rides as it did without any unusual movements or noises I would say you're safe. Do the coin tap trick as mentioned as well to give you peace of mind.


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## curacao0311

My stepmothers Synapse has a similar crack that I've been keeping an eye on for a year. Seems to just be the paints reaction to extended stays in the sun, as I have seen no advancement in the line


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## robdamanii

Traci said:


> I really don't understand the reason for today's Carbon-frame, if you're racing. However, there's no doubt that Carbon is the future.


Whiskers1/Look75 is back again I see....


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## dhtucker4

I know that Time, Giant, Specialized, Serotta, Fuji, Litespeed, Merlin, Orbea, Trek, Parlee, Cervelo, Calfree, Crumpton, etc. guarantee their high-end carbon frames for life - if their owner doesn't have a major accident or crash while riding. I heard that the Trek warranty isn't worth squat - their consumer relations are very poor at best. Parlee least-expensive frame is guaranteed for 10 years. 

Look, Ridley, LaPierre, Colnago, etc. warranty their frames for 5 years or less. 

The Pros ride 10,000-plus miles per year, training and racing.


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## spookyload

I had a Look 481SL that did that. I was told by Look that there is a filler material similar to Bondo that is used at the joints to smooth them prior to painting. As a frame ages it becomes brittle and cracks under the paint making the frame looked cracked. Look warrantied the frame for me anyways BTW. I would guess that is what is happening to your frame as it is about the right place for a joint in the frame.


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## Fireform

All materials fatigue eventually. I've seen forged steel front dropouts fail (not pretty), steel rear hangers, aluminum welds--it's hardly restricted to carbon, but there are just so many carbon bikes on the road. Ti is the best, but even there its not impossible.


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## hoopingkld

Fellas,

Spot a paint crack on the 5.2 my friend ride. start in the middle of TT right where TT meets the seat post and goes to the right side...pretty freaky. There is no flexing when riding but we don't race ....

Have you been experience such a crack on your Madone? Is there a better way to detect that rather than bring it to inexperience LBS who does not have much exposure to Trek frame crack.


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## jsedlak

^ that is probably a paint crack but have it double checked if possible.

The Madones were prone to paint cracks in that area due to the seat mast. My 08 5.2 had a similar issue in that area. The seat mast is designed to flex a little in that area for comfort but the paint is... well it is paint.


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## HurtLocker

*is this a crack in the paint or possibly an underlying crack?*


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## HurtLocker

My initial thoughts are that it's in the clearcoat, because I can't see the carbon cracking in so many different directions.


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## Clicker7

It looks like the gel-coat/paint.

Take it in to your LBS for some live opinions.


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## skill3

Generally, carbon that is failing cracks linear (straight line along a a seam or joint). The only time you would see a crack going in different directions would be if you crashed it. The ORBEA in the photo, press the cracked area and see if it is "soft". If it is, it's definitely cracked carbon.


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## froze

I did read some place that Cannondale was having an issue with the gelcoat cracking on their bikes since China took over production; but it's just purely cosmetic.


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## HurtLocker

the bike has been raced a lot, but i have (thankfully and knock on wood) never crashed it...there is no give when i push around the area, so my thoughts are that it is just the top coat, my wrench seems to think so too.


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## PaxRomana

The "crack" on that Time is a common paint issue.


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## Christopaul

Are there any inexpensive ways to X-Ray a crack in question? If so, where? If not, then the coin test mentioned earlier is the best way. If you hear a muted thud sound, then you would be wise to discontinue riding the bike. Some club members have sent their frames to Calfee in Santa Cruz California for repairs (including frames they don't make, i.e. Trek, Specialized & Orbea etc.). A more common place of failure is around the chain stay and derailleur hanger.


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## andresmuro

curacao0311 said:


> My stepmothers Synapse has a similar crack that I've been keeping an eye on for a year. Seems to just be the paints reaction to extended stays in the sun, as I have seen no advancement in the line


Cool stepmom!


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## gordy748

The trouble with carbon is the rapidity of failure. They go from crack to catastrophe in an instant.

I have a friend (a 1%er) who had a Lightweight wheelset. The front simply, utterly assploded one day when he was in the Alps. I ran into him a year later in London and he still had scars on his face.

I also used to row, and practicing a racing start one day saw a crewmate's oar snap in half. One stroke it was fine, the next he's sitting there looking at a pole with the other half of his oar floating merrily down the river.

Carbon is great but I'd treat any cracking with concern.


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## froze

Christopaul said:


> Are there any inexpensive ways to X-Ray a crack in question? If so, where? If not, then the coin test mentioned earlier is the best way. If you hear a muted thud sound, then you would be wise to discontinue riding the bike. Some club members have sent their frames to Calfee in Santa Cruz California for repairs (including frames they don't make, i.e. Trek, Specialized & Orbea etc.). A more common place of failure is around the chain stay and derailleur hanger.


What happens to a bike that is brought in for inspection and the LBS, along with the bike manufacture, decides to send the bike back to the manufacture for inspection? I'm sure the manufacture isn't going to do a coin check! I would think they would do something a little more high tech then that.

I did read however that X-raying a CF frame did NOT guarantee that a crack would be found. The kind of cracks that a X-Ray can detect are those that go all the way through the CF; if the crack only goes partially through the X-Ray will miss it. And X-Ray also will miss damage called a barely visible impact damage. This type of damage has no visible clues on the outside of the tube, but it stressed cracked inside the tube, this sort of damage is detectable by using ultrasound.

Something I did learn recently about cracks that are just in the GelCoat, you need to fix it as soon as possible because any water that penetrates that GelCoat crack will start the corrosion process of any aluminum lugs either external or internal lugs, or AL bottom bracket housing.


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## sovereign

Seat tube. 4 inches long. The quarter test does not produce a "thud" sound, but a higher pitch, which makes sense being in the center of the tube. Right? Opinions? It will be a while before it can make it to the shop.


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## froze

That is just a photo so it's difficult to tell what's going on. But from the photo it looks to be a scratch, or a crack in the paint. Can you feel "hairs" sticking up from that mark? I would take it in to be safe and get whatever they say in writing...just in case their wrong, they won't charge you to look at it.


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## sovereign

Appears cosmetic.


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