# Frame carbon crack or just paint



## lmar77 (Dec 12, 2008)

Please let me know your thoughts...


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## tlg (May 11, 2011)

No way to diagnose from a picture on the internet. But sure looks like a crack. Stop riding and take it to your dealer.

It's a really straight crack. Perhaps it's where the two parts are joined and it's just a paint crack. No way of telling from a picture or knowing the frame construction.


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## fronesis (Jan 22, 2014)

We'll all be guessing from the picture....

But my guess: that definitely looks like a crack to me.

I've had two carbon bikes with cosmetic damage to the outer finish that weren't cracks. But what you have there looks like a crack because it's moving/spreading around the tube the way a crack in the structure would do. 

In the China carbon thread someone posted a picture of his bike after he was hit by a car: the frame is cracked in half a dozen places (but not broken, just cracked). If you go look at his images you'll see that they look A LOT like yours. 

I have a small crack in the seat tube of my current bike (right at the FD band) that I am pretty sure is just in the outer gloss finish. I've been riding the bike and watching it carefully. I tell you that so you'll know I'm not hyper paranoid about these things before I say this: I would NOT ride your bike if I were you.


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## ljvb (Dec 10, 2014)

Same response as other, hard to tell from a picture. But.... Typically a chip in the paint would be asymmetrical and jagged in nature. Yours is a straight line, parallel to the weave. That said, typically the types are made up of multiple layers, which each layers weave perpendicular to each other, so the crack may only be in one layer, and not through the entire frame. Get it checked out though.


See picture below (TSA chipped my frame by throwing the lock they cut off my travel case.. even though I included the key inside a manila envelope tapped with clear packing tape and instructions to toss the key into the care after inspection) It bounced around and left a few chips like you see here.


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## 9W9W (Apr 5, 2012)

I have a giant chain suck caused carbon gash in my BMC and I am riding around on it like a flaming bat out of hell.

No guts. No glory.


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## pmf (Feb 23, 2004)

ljvb said:


> See picture below (TSA chipped my frame by throwing the lock they cut off my travel case.. even though I included the key inside a manila envelope tapped with clear packing tape and instructions to toss the key into the care after inspection) It bounced around and left a few chips like you see here.


God, would that ever piss me off. It's almost like those TSA jerk offs enjoy doing that kind of crap. Did I say almost?

Back in the days when I traveled with a bike, I always took my titanium Litespeed. I remember once standing in deGaulle airport watching two French gorillas unload our plane en route to Italy. The luggage compartment was maybe 5' off the ground. They grabbed one of the hard cases, pulled it out and let it fall to the ground. Did the same to my wife's case. We're thinking great, WTF are we going to ride on our bike tour in Tuscany. They showed up late at the Pisa airport, but the bikes were intact.


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## ljvb (Dec 10, 2014)

I filed a complaint, which included the cost of repairing (really just a clearcoat respray) as well as the cost of a replacement frame.. never heard back.. I was pissed.... hell I am still pissed.. and I have to see those jokers twice a week (I am on 4 flights a week.. every week.. have been for almost 5 years now, always through ATL... I hate that place).


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## bradkay (Nov 5, 2013)

I am surprised that no one here has mentioned the simple test for a carbon crack. Take a large coin (a US quarter will do nicely) and tap the tube in which the crack appears. The tone that you hear will change from a high "tap" sound to a dull "tonk" sound if there is a crack. Tap up and down the tube to be sure that you hear a definite change in the tone that is being produced.


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## tlg (May 11, 2011)

bradkay said:


> I am surprised that no one here has mentioned the simple test for a carbon crack. Take a large coin (a US quarter will do nicely) and tap the tube in which the crack appears. The tone that you hear will change from a high "tap" sound to a dull "tonk" sound if there is a crack. Tap up and down the tube to be sure that you hear a definite change in the tone that is being produced.


No one mentioned it because it's useless. 
If that is a joint, it's going to have thickness changes so it's tone would change no matter what.


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## pmf (Feb 23, 2004)

ljvb said:


> I filed a complaint, which included the cost of repairing (really just a clearcoat respray) as well as the cost of a replacement frame.. never heard back.. I was pissed.... hell I am still pissed.. and I have to see those jokers twice a week (I am on 4 flights a week.. every week.. have been for almost 5 years now, always through ATL... I hate that place).


Atlanta and Chicago O'hare are two airports I'll actually pay a higher ticket price to avoid going through. 

You have to love little big people like TSA. They're low skilled, barely educated losers who suddenly get power to push people around and revel in it. I was once flying out of Austin TX and dealing with TSA and they were really nice and polite. I said to one of them, I appreciate you being polite to me -- you could teach the TSA guys in DC where I come from a few lessons. The guy smiles and says 'you're in Texas -- everything is better here'. 

I'll never forget finishing my Ph.D. 25 years ago. This was back when you got one free run at the laser printer to print out the 8 copies of your dissertation you needed. They had all kinds of stupid rules about the font, the margins, etc. Before defending, you had to submit two copies to the graduate school. Why, I'll never know. It's not like they did anything with them. So I took it into the grad school office and there's this secretary there. I plop it down on here desk, and she pulls out a ruler and starts measuring the margins and equations on random pages. I just about had a heart attack watching her. And she was obviously loving every minute of it. All the professors probably treated her like ****, and here was her chance to reign over someone -- even if it was a lowly grad student.


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## lmar77 (Dec 12, 2008)

tlg said:


> No one mentioned it because it's useless.
> If that is a joint, it's going to have thickness changes so it's tone would change no matter what.


Actually, i don't hear a change at all, no matter where i tap it sounds the same to me


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## ljvb (Dec 10, 2014)

pmf said:


> Atlanta and Chicago O'hare are two airports I'll actually pay a higher ticket price to avoid going through.
> 
> You have to love little big people like TSA. They're low skilled, barely educated losers who suddenly get power to push people around and revel in it. I was once flying out of Austin TX and dealing with TSA and they were really nice and polite. I said to one of them, I appreciate you being polite to me -- you could teach the TSA guys in DC where I come from a few lessons. The guy smiles and says 'you're in Texas -- everything is better here.


I fly out of BWI every Monday morning. DCA is horrible compared. I have not used IAD in a long time but the last time was painless for my flight to South Africa. 

I had an ex who was tsa at DCA... and yeah, authority complexes, almost every one of them. Last few weeks have been to Tallahassee via atl, Tallahassee airport staff are as friendly as can be. And no lines at security. I left my office at 445, drove tommy hotel to check out quick, drove to the airport, got their around 515, went to the delta desk, got on the standby list for the 6pm flight, went through security, sitting at my gate by 530 lol. (My original flight was for 8pm but I wanted to get home earlier. And I still got bumped to "first class".. as much as that exists in the boring 717s or crj900s)


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## tlg (May 11, 2011)

lmar77 said:


> Actually, i don't hear a change at all, no matter where i tap it sounds the same to me


Maybe you're tone deaf. 
Here's some resources on why coin testing is not a safe method for determining frame damage.

The Limitations of Tap Testing
Carbon Bike Repair | COIN TAPPING CARBON: DOES IT WORK?


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## Migen21 (Oct 28, 2014)

My LBS often cut's up frames for warranty purposes, and we've experimented with the tap testing stuff. It's not reliable at all.

Sure, it *can*, *sometimes*, indicate a problem, but it might not... It's not definitive.


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## Lombard (May 8, 2014)

Two words - bike shop. Take it to a good reputable one where they can determine if it's safe or not. A picture may be worth a thousand words, but seeing it in person is worth 100 thousand words. They will come to a much better conclusion than us schmucks on the internet.


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## biscut (Dec 15, 2016)

Sorry to *hijack* (pretty good right?) I can't let a chance to get a dig at TSA go...

HATE EM!!!!!!!! Every time they get tested they FAIL, time and time again. Desperate to be somebody.


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## charlitin (Oct 2, 2011)

lmar77 said:


> Please let me know your thoughts...
> View attachment 318972
> View attachment 318973


That is a crack. Very similar to two warranty replacements I got for one on the bottom bracket and seat tube of a scott cr1. If it is under warranty they would replace it. If it is not under warranty you can repair it. 400-500$ depending on the area and the demand. They do pretty good jobs now days. I got a repaired frame and you can't even tell. 


Sent from my iPhone using Tapatalk


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## GKSki (Nov 12, 2014)

What exactly is that riveted to the BB shell?


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## Migen21 (Oct 28, 2014)

I don't think that's a rivet. Pretty sure it's a low profile allen head screw that holds the internal cable routing access cover on.


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## Pirx (Aug 9, 2009)

My two cents: This is clearly cosmetic. Manufacturers often use additional layers in the BB area, which can result in a step change in carbon layers there which is smoothed out by additional resin in the form. That outer resin layer can crack under stress, but such cracks have no effect whatsoever on the strength of the frame. A structural crack in the tube you show would _never_ have such a beautiful regular appearance. On top of that, your "crack" is not in a highly stressed area.

Having said all of the above, sure, take it to the dealer and talk to them. Pictures can be misleading.


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## jaggrin (Feb 18, 2011)

I can definitely tell from the picture it is a crack


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## kapusta (Apr 26, 2004)

I had a crack that looked a lot like that near my bb on an old Y-foil frame.

It was just the paint where the bb was bonded to the downtube. A common issue on that bike.

Not saying that is in fact the situation here, just that I would NOT assume for sure it is a crack in the CF.


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## okiefo (Jan 10, 2009)

Looks like a bond line paint crack to me. I've seen it a thousand times.


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