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Old 06-28-07, 11:47 AM   #1
Carbon Based
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Carbon fork damage-is this significant?

I just purchased a Serotta Ti frame with EMS carbon fork that I'm starting to build up. I'm a little worried about the fork though, as there seems to be some damage to its top layer. Is this damage potentially dangerous? Should I replace the fork? I'm hoping its mainly cosmetic, as the project is stretching my budget as it is.

Pictures here:
(click for larger)
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Old 06-28-07, 12:03 PM   #2
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Hard to be SURE from the photo, but that does look purely cosmetic to me. You may want to find out the thickness of the fork tubing and compare that to the depth of the scratch.
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Old 06-28-07, 12:05 PM   #3
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Looks like a long split running the full diagonal of the picture frame. If it's not a trick of the pic, yeah, I'd say it's significant. Try contacting EMS.
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Old 06-28-07, 12:07 PM   #4
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Looks like the clear coat got chipped off from the picture, with partial clear-coat delimination. Do the tap test to make sure the under-layers are not delaminated.
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Old 06-28-07, 12:08 PM   #5
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Originally Posted by DMF
Looks like a long split running the full diagonal of the picture frame. If it's not a trick of the pic, yeah, I'd say it's significant. Try contacting EMS.
I think this is just some sort of join line from manufacturing, as it runs the full length of the fork on both sides and the inside and outside. I'm more worried about the scratching/"peeling"
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Old 06-28-07, 01:13 PM   #6
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If you're 100% SURE it's just the lamination, you're fine. If you're 99.9% of less, I wouldn't risk it. I have a fork sitting next to my computer right now because I'm not sure (the front wheel failed and struck the legs). It's only here so I can take measurements and ask ebay sellers to measure the same, and hopefully find a fork with the same dimensions. I went over the bars once, and don't plan on risking it again.
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Old 06-28-07, 01:28 PM   #7
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In regards to the picture - it appears that the layer underneath is a little rippled - is the carbon dented at all?? I am no expert, but it looks like more damage than just a scratch, or maybe just bad lighting?

I would like to suggest that you buy a cro-mo fork. A lot more reliable - never really have to worry about them snapping like twigs.

I would never ride bike with any carbon on it. I don't even trust aluminium - except my Mongoose Tetra SX Mountain bike which has thick tubing with big welds and reinforcements.
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Old 06-28-07, 01:40 PM   #8
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I would never ride bike with any carbon on it. I don't even trust aluminium - except my Mongoose Tetra SX Mountain bike which has thick tubing with big welds and reinforcements.
Big welds and reinforcements may look comforting, but they're not really the issue here!

Carbon fiber is VERY STRONG when done right. Aluminum is strong too (about as strong as steel per unit weight).

The issues with CF and Al are their failure modes. Steel is pretty forgiving, it usually bends a lot before it breaks. Al and CF have been observed to fail in more catastrophic and sudden ways. Big welds and thick tubing may make a frame stronger in the first place, but it's doubtful that they'll affect how it ultimately fails. (I, for one, will ride just about anything )
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Old 06-28-07, 01:46 PM   #9
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Quote:
Originally Posted by C_LOGAN
...

I would never ride bike with any carbon on it. I don't even trust aluminium - except my Mongoose Tetra SX Mountain bike which has thick tubing with big welds and reinforcements.
Are there really stastically significant problems with the materials? Yes, we've all hear stories - or in my case, I've not actually heard stories, but heard "of" stories. But geeze, there's so many people using these components, are they dangerous on a statistically significant level? Especially aluminum, but carbon also.
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Old 06-28-07, 01:47 PM   #10
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I'm pretty sure now that it's just the top lamination. The weave below isn't dented or marked, so hopefully it'll be ok. I tried the "tap test", which didn't indicate any damage to the fork. I've heard this isn't so effective, though. Well, now I'll change the fork from an immediate task to long-term, when I decide to upgrade to a modern headset. I'll probably get a modern CF fork when I do replace it. Experience with automotive uses of carbon fiber makes me a little skeptical of the "carbon fiber is fragile and you will kill yourself if any part on your bike is made of it" crowd. Do agree about the failure modes, though. Thanks everyone
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Old 06-28-07, 01:50 PM   #11
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Quote:
Originally Posted by moxfyre
Big welds and reinforcements may look comforting, but they're not really the issue here!

Carbon fiber is VERY STRONG when done right. Aluminum is strong too (about as strong as steel per unit weight).

The issues with CF and Al are their failure modes. Steel is pretty forgiving, it usually bends a lot before it breaks. Al and CF have been observed to fail in more catastrophic and sudden ways. Big welds and thick tubing may make a frame stronger in the first place, but it's doubtful that they'll affect how it ultimately fails. (I, for one, will ride just about anything )
I know they are strong materials - I was referring to the failure mode when I said that you don't have to worry about steel forks snapping like twigs.

I just don't like the idea that a bike can fail in an instant without any obvious signs.
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Old 06-28-07, 01:55 PM   #12
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Quote:
Originally Posted by Camilo
Are there really stastically significant problems with the materials? Yes, we've all hear stories - or in my case, I've not actually heard stories, but heard "of" stories. But geeze, there's so many people using these components, are they dangerous on a statistically significant level? Especially aluminum, but carbon also.
It all comes down to what can happen. Carbon and Aluminium can fail in an instant, whilst steel fails over a longer time period with clear signs that a failure is occurring in most cases. This is what I have read and I would rather be safe than sorry..

I would probably exceed the weight limit of any carbon fibre bike anyhow.
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Old 06-28-07, 02:51 PM   #13
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I, for one, will ride just about anything
If it feels good to ride, I will ride most anything, also.

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