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Carbon frame scratches

Hi folks, 

 

 Just looking for a bit of advice/opinion.... I've been getting into road cycling steadily in the last three years and four monthas ago invested in a carbon Planet X RTD-80.

Last week a taxi slammed on its brakes in front of me to avoid a collission and I slid under the back of his car (nobody's fault, just one of those things). My back wheel buckled (beyond repair IMHO) and caused a little scratching on the inside of my chainstay. I can't work out if the scratch has gone through to the carbon, there's no fraying, however I've heard horror stories about carbon frames failing. 

Also, when I removed the rear wheel, which has threaded axle, I noticed the threads seem to have indented into the droputs, in particular the driveside one... (wheels came with the bike - Fulcrum racing sport disc). I was thinking, surely Planet X wouldn't supply wheels that would damage the bike...

 (I've gone to LBS for advice but they're not interested)

Otherwise the frame seems perfect - no visible cracks, tapped over the scratched area and no difference in pitch (don't know if that's an old wives tale about tappping carbon). 

For the scratches I'd thought about just putting a little nail varnish on (as Specialized recommend for their carbon frames) and some chopper tape over that...

Can't get out on it until my new wheelset arrives. Incidentally - ordered cheap and cheerful Mavic Aksium Discs - anybody had any experience with them? Reviews seem quite good.... 

Thanks,

J

 

 

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12 comments

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surly_by_name | 7 years ago
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Errrr .... I had to look a couple of times to even find what you were talking about. I can't see the rest of the bike, but neither of the scratches shown in the photos are signs of impending structural doom. You should stop worrying and go for a ride.

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jamoose | 7 years ago
1 like

Thanks guys. I've emailed PX but haven't heard anythinbg back. I took the forks out and they seem fine, so I'm a lot more confident. New wheelset is arriving today smiley, so hopefully should be up and running soon. 

Not having a bike is absoluteley awful!! 

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freebsd_frank | 7 years ago
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I think Jack Osbourne snr above makes a good point. Give your fork and steerer a good look over since you've had a crash. You don't want those bits to give way at any sort of speed due to some damage you may have overlooked.

The damage on the chainstay looks superficial. It doesn't look like it's damaged the carbon fibres. I would get in touch with Planet X if you want to touch it up. They should know what matrix material (ie. plastic or resin) they've used in construction and hence what is safe to use on it.

The dropout looks like it's just got regular wear and tear and shouldn't be anything to worry about.

 

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madcarew | 7 years ago
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None of that looks anything more than superficial to me. Certainly my frame has much worse scratches on the chainstay and that has been cleared by a carbon frame maker for use. Certainly the drop out doesn't look  bad at all. 

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Jack Osbourne snr | 7 years ago
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Emailing PX makes sense.

In my humble opinion the scratches are superficial and absolutely not going to cause any issues. Seal them up to stop any further deterioration and you'll be good to go.

HOWEVER... as with any crash damaged frame, I would be examining every square millimeter of it for any signs of damage ie cracks, cracks in lacquer, whitening in lacquer etc.

I would also take the fork out and examine both the blades and the steerer. Don't just assume it's okay.

I suspect you'll be fine though.

 

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jamoose | 7 years ago
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The hanger is metal, the bit it's attached to i beleive is carbon as it's ever so slightyl frayed around edges. I suppose the metal hanger strengthens it. The other dropout seems fine. I'm going to email Planet X to see what they say now...

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part_robot | 7 years ago
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Isn't the dropout metal?

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jamoose | 7 years ago
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And this is the dropout.... When I crashed the wheel came out of the dropout a bit which is why there's a bit of extra scratching going in the direction of the mech...

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jamoose | 7 years ago
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Thanks everyone for your comments on this, much appreciated! Having looked at it again I feel a bit better about it. Sorry about the links to the pics, I'll try to post them underneath here to give you a better idea...

 This is the chainstay... 

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fixit | 7 years ago
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if there is no fiber, don't wory , if you can see fiber like torn cloth, throw it away. you can cover it with some epoxy glue to seal it.  for the grooves on the dropouts from the axle, dont worry with that too, everybody has that when there is a threaded axle present.

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StraelGuy | 7 years ago
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Agree, doesn't sound like serious damage (pitch is used by carbon fibre repairers but using pretty sophisticated kit). Buy a bottle of cheap clear nail varnish and paint it over the scratch to seal it.

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madcarew | 7 years ago
1 like

This is one of those funny ones. Anyone on here can say anything and there is no comeback, little evidence of their expertise or anything, Your LBS won't beinterested because of liability. That said.....

I have a cannondale evo 6 hi-mod. The chain came off the chainrings and scored the frame deeply. I took it to Graeme Pearson who is a world reknowned carbon frame builder, and very very good repairer and he ok'd it. I can't see any fibres, there's deep (.5mm deep?? scoring through the clear coat and in to the epoxy. 

My local LBS also manufactures bikes, and they have manufactured a few carbon bikes. They've (as yet) not had a single carbon frame from any manufacturer fail catastrophically (as in failed in such a way that it put the rider in unexpected peril) post crash. Carbon frames tend to either break completely immediately, or fail gradually over a period of time. They have had broken seat stays, chain stays, down tubes, seat tubes, bottom brackets, head tubes cross tubes that have all cracked through or around and the bike has still been rideable, much as you would expect with an aluminium or steel bike. 

I can't view your pictures but my personal opinion is that the drop outs are fine, and probably the inside of the chainstay. If you want something to compare it to, look under your fork crown where stones chip and score the carbon fibre. You'll like as not find it quite messy in there and be able to compare those to your chainstay scrape. Either way, even if your chainstay does fail completely, it is very unlikely to deposit you unceremoniously and unexpectedly on the road.

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