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Is this a crack?


TooManyMatts

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Ya its absolute rubbish. I bough a bike a couple years ago that had a "lifetime warranty" only to find that the small print contained a clause that states that the lifetime of a carbon bike is 5 years so after 5 years the warranty didn't apply.

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Ya its absolute rubbish. I bough a bike a couple years ago that had a "lifetime warranty" only to find that the small print contained a clause that states that the lifetime of a carbon bike is 5 years so after 5 years the warranty didn't apply.

 

Which brand?

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Oh, so you are sure that isn't an alu lug?

 

Absolutely.

 

Look, okay there will be an aluminium collar (tube-shaped) inside the carbon structure, but the structure around the collar will definitely be carbon. And the carbon bit is the bit that is looking as if it is cracked.

 

What Pain said is correct, to a point! The "paint" is in fact more of a gel-coat that covers the entire carbon section of the frame, as well as the face of the BB insert / shell. That's why it looks so thin - it is actually the gel coat, which forms an integral PART of the carbon structure (protects it from the elements) but is not the actual carbon itself.

 

The carbon itself would be under & next to the alu section (shiny bit in the picture) and the alu would be glued flush against the carbon.

 

The piece in question, however, is NOT alu. That forms part of the carbon frame. The only alu bit in there would be a collar that the suspension bolts go through. You cannot weld that section, but you may be able to get someone to do a carbon repair on it. Much like you repair fibreglass structures. But you need to know what you're doing in order to carry out the fix, and it's quite a long process.

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Which brand?

 

It was a Scott.

Absolutely.

 

Look, okay there will be an aluminium collar (tube-shaped) inside the carbon structure, but the structure around the collar will definitely be carbon. And the carbon bit is the bit that is looking as if it is cracked.

 

What Pain said is correct, to a point! The "paint" is in fact more of a gel-coat that covers the entire carbon section of the frame, as well as the face of the BB insert / shell. That's why it looks so thin - it is actually the gel coat, which forms an integral PART of the carbon structure (protects it from the elements) but is not the actual carbon itself.

 

The carbon itself would be under & next to the alu section (shiny bit in the picture) and the alu would be glued flush against the carbon.

 

The piece in question, however, is NOT alu. That forms part of the carbon frame. The only alu bit in there would be a collar that the suspension bolts go through. You cannot weld that section, but you may be able to get someone to do a carbon repair on it. Much like you repair fibreglass structures. But you need to know what you're doing in order to carry out the fix, and it's quite a long process.

 

This makes me sad, a carbon fix in such a high stress area sounds like a bad idea. Is there a chance that it is a surface crack caused by the flex int he carbon at this point? A friend's carbon bike once had a crack near the seatpost which looked a lot like this one and the manufacturers said it was just the paint and that he shouldn't worry.

 

It looks like I'm stuck with this now. So if I do sand down to find that its just surface damage, then I could just repaint with clear.

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It was a Scott.

 

This makes me sad, a carbon fix in such a high stress area sounds like a bad idea. Is there a chance that it is a surface crack caused by the flex int he carbon at this point? A friend's carbon bike once had a crack near the seatpost which looked a lot like this one and the manufacturers said it was just the paint and that he shouldn't worry.

 

It looks like I'm stuck with this now. So if I do sand down to find that its just surface damage, then I could just repaint with clear.

 

The carbon shouldn't be flexing at that point... It should be designed with high load forces in mind and made as strong as possible. If it flexed, it could be far worse than just a crack.

 

But yes, it COULD potentially be as a result of flex. But in that case, it's a predictor of failure. And chances are that you won't be able to see the crack (if there is one) with the naked eye, unless you use something to penetrate the area and then sand it down again (think of tippex and how it will seep into cracks)

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Dude, Sorry to say... But her days are numbered...

 

This is one of the risks of carbon frames, the paint should never crack, as it technically is not as stiff as the carbon under it.

 

The lug is bonded into the Carbon and if I look at the crack progation, it seems as if it will become circular around the lug, and on the alu, section of the lug., it will look like a paint crack and eventually more and more movement will be experienced as is a tension crack on the non-drive side. Each pedal stroke is opening the crack.

 

Have you ridden the frame?

Was it creaking?

 

 

Thanks

Ken

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