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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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