Did I ruin my carbon fiber frame?
 

A few days ago I pulled the wheels off my CX bike to swap some different tires on and discovered a scuff/scrape on the inside of the non-drive-side chain stay that is around an inch long, just forward of the disc brake caliper. It's about an inch forward of the disc, so it's possible this happened when removing/installing the rear wheel at some point, or has happened gradually over time from removing/reinstalling the rear wheel (the bike is 3 years old, the wheels get removed frequently to swap tires and wheelsets). When I'm inserting the rear wheel it seems like the disc could briefly rub on this spot. Has anyone seen this before on a disc brake bike?

This bike has also been through a handful of muddy CX and gravel rides/races so it's possible something got jammed in there and scraped it, but it seems like a weird spot for that to happen (and I don't remember anything like this happening) so I'm assuming it's from the disc when removing or installing the rear wheel.

I have no idea how long it's been there, but I'm wondering what others think - is this a cause for concern, or just an aesthetic blemish that I don't need to worry about? I don't see any carbon fibers sticking out or signs of cracks or anything like that, but the paint layer is definitely scraped off. Should I add some tape over it to protect it in the future? Or just wrap some electrical tape around it and fire-sale it on FB marketplace before it assplodes?

I'm planning to take it to my LBS to see what they think, but figured I'd check with the experts on BF as well just to get some additional data points.


https://cimg6.ibsrv.net/gimg/bikefor...6065fb2fa7.jpg
https://cimg8.ibsrv.net/gimg/bikefor...88fb8a929d.jpg

Looks fine. Very robust area for a bicycle, least of your worries. Get ready for the usual, tap with a penny, take it to a shop ask for ultrasound analysis, etc. The final conclusion will be the typical "this is why I ride steel".


I just noticed you are a member since 2006 and you turn to this forum for a reasonable response you are not aware of for a scuffed carbon frame?

Structural integrity looks intact. Paint, not so much. Ride it, but keep an eye on things. Could put some paint protection film on it to stop any further abrasion.

scuffing
 

usable as mentioned but depreciation$$$ took a hit.

Solid criticism.
My defense is that I always thought these stories were made up until one day it happened to me.

This ^^^

Black Knight: 'Tis but a scratch.
Arthur: A SCRATCH? Your arm's off!
Black Knight: No it isn't!
Arthur: Well what's that then? (pointing to the arm lying on the ground)
Black Knight: I've had worse.
Arthur: You LIAR!
Black Knight: Come on, you pansy!

Looks like only paint damage with either residual paint on, or light scuffing, of the epoxy layer underneath, so should not affect function.

Not sure it is actually caused by the rotor though; damaged spot seems too far forward?

I assumed it was caused by the side of the tire rubbing the stay, but it's near the hub end of the stay, nowhere near the tire. How could this get scraped there? It doesn't look like a one-time scrape, more like accumulated damage. It's very odd.

Is it possible for the rotor to touch there when the wheel is being put on the bike?

If it's a 56 you need to send it to me for proper disposal .... don't risk your life on an unsafe bike.

Otherwise, continue to ride it hard.

My shop is doing an overhaul on the bike (unrelated to this) and will do a more thorough inspection on the frame once they strip it down, but they didn't seem too worried about this.

They said this appeared to be surface/paint damage only. It is likely caused by me being careless when removing and/or re-inserting the rear wheel and the rotor is contacting the stay, scratching it a little each time - so over time it's scuffed up that spot and worn off the paint. This is apparently common (according to them) and they said they've seen other carbon/disc bikes with similar scuffs.

I will admit that I can be a little rough on my equipment so I'll be more mindful when removing/inserting my rear wheel in the future, and will probably add some tape to this spot to try to limit any future damage.

If they come back with any more info I'll update the thread.

Oh no! Don't ride it or it was assplode, LOL!

Seriously, that just looks like paint was taken off. Nothing to worry about. Just ride it and don't look at that area!

Flip side of the coin is that it could be used as evidence that you wore the bike out and need a new one. At least that’s how you present it to your spouse.

Since you will keep removing and reinstalling the wheel, perhaps put something like this over the spot for future protection. (I would probably just use electrical tape, which will also work.)

This!!! ^^^

Yes honey, it's totally ruined. I can't believe it either. The shop says the supply chain stuff is really crazy and they have no inventory, but they made some calls for me and managed to find this S-Works Aethos in my size which I'll have to make do with for now.

Im sure you can slum it for a while.

S-Works? Honey, I need some new clothes. I'm sure you will be just as happy on a used Huffy. 🤣

Approved for content. Proceed with implementation. Let us know how that goes for you.

Personally, I wouldn't settle for the Aethos when the new 2023 Scott Foil Ultimate can be had for just $2000 more.

And his answer is, “Of course you do dear. Will that be Ted Baker, Dolce or Jimmy Choo today?”

That is, if he can afford S-Works.

Safety Tip: Do not mention Christian Louboutin

My daughter bought a pair of CL tennis shoes to wear at her wedding reception. All I could do was shake my head.

A cheaper CL option than the style the brand is know for, I would guess. That said, I agree with your response.

I would more than shake my head if that was on my credit card. But if it was hers, shake away.

Her credit card, and she can afford it.