Gave the roadie a long overdue service today and discovered some wear on the chainstay from the tyre. Looks like the wheel isn’t dished properly and has been rubbing when the frame flexes. Idiotic mistake not to notice sooner but hey-ho. It’s about the size of a 20p piece and looks to have gone through a couple of layers of carbon, maybe 2-3mm deep. So the question is, is it safe? I’ve been riding it like this for a while I guess on some pretty fast and bumpy descents and it hasn’t broke yet, but I’m not taking that as proof. New frame time?

No one can tell you definitively.

You’d think it would crack over time rather than go quickly

2-3mm would be most of the way through the tube wall I would have thought…

As above, I wouldnt expect a carbon frame to be any thicker than that unless it’s a joint. If you are sure it is that deep then get a quote from a carbon repair place. They will be able to sort that easily and cheaper than a new frame.

Some pics…

New frame time?

…yes, absolutely, it’s for the bin, buy that shiny new frame Daz. 😉

Edit: bloody hell, how did you not notice that rubbing? Good resistance training though I suppose… 😯

Didn’t rub when I wasn’t on the bike. Supposed to be buying a new full-susser imminently, the Mrs will kick off I get a new roadie too.

So the question is, is it safe?

I’ll answer a different question…

Would I ride it? – Yes, while periodically (more frequently than your current regime!) inspecting it to see if anything unpleasant was happening.

Would I advise you to ride it? – No I wouldn’t, I’d not suggest to someone else that they ride with a damaged frame like that when I don’t know the structural details of that particular frame and it *might* pose a risk to them, I wouldn’t want it on my conscience if something bad did happen.

^ taking those two answers on board I think you need to realise that you need to make your own mind up either way!

The good news is that if/when it breaks it’s probably easily repairable, but a ‘pre-emptive’ reinforcement repair may be better in the long run as if it were to go while riding there’s no telling what other damage will occur because of a failure there.

that’s a good job you’ve done there.

It will probably keep going for ages as it’s nicely done in a taper so low stress concentration but in reality I would get some photos with a ruler against it to a carbon frame repair place. The good thing is they can get good hints of the layup from that wear patch 😀

That’s probably repairable – have you got a buckled wheel?

Ah. Hmm. There’s carbon repair places that can fix that sort of thing up so that’s probably your best option. That’s quite a lot of layers it’s gone through so worth getting it sorted at some point I reckon.

yes, absolutely, it’s for the bin, buy that shiny new frame Daz.

Ignore such Horse shit! It’s Completely repairable.

But yep, I would say that it almost rubbed through, get it fixed, or when it goes it’s going to be much more expensive…

**** hell, proper job there! You appear to have gone right through the tube in the top right quadrant, I’d be getting that repaired certainly before I did all that much more on it. Then again… it’s a chainstay, failure is fairly unlikely to be catastrophic.

Is this one of those magic eye things – I can never get them

The wear patch looks like it’s standing proud of the tube to me. Can’t make myself see it as indentation

Ignore such Horse shit! It’s Completely repairable.

Keep calm, he was joking. He knows my propensity to use any crap excuse to buy a new bike! Obviously you weren’t to know that though. 🙂

I would guess the problem is that if it’s been rubbed there it will be rubbed there even more if you got it repaired as the repair won’t be flush.

It will be somewhat weakened there, and carbon doesn’t tend to fail in fatigue – cracks can’t propogate as it’s the fibres that take the load so they just fail one by one, but the matrix between should be less stiff and remain intact. It would take one big hit to break it, if it was going to break.

I’d probably want to replace it as it looks like you’ve gone through quite a few layers of the lay-up there – unless I’m wrong about not being able to leave clearance with a repair in place.

I would guess the problem is that if it’s been rubbed there it will be rubbed there even more if you got it repaired as the repair won’t be flush.

If the wheel dish is off that will be a factor (worth confirming OP)…

Looks like the wheel isn’t dished properly

As for the repair protruding; it doesn’t have to, at least not in that area, relative to the tyre, scarf back the tube a couple of inches either side, take the paint back a bit further, blend/fill to get a smooth support, and then then bridge over the whole lot with a couple of 12k layers.

The better outfits will sort the paint to make it near enough invisible if you want, but given the location you might be happy enough with a structural repair only…

Consider maybe slapping some helicopter tape over as well to prevent future rubbing?

Wheel dish wasn’t off, but the wheel was off-centre. Stupid mistake which is pretty embarrassing to admit, but I’d changed the bearings in the hub (Novatec) and put a washer on the wrong side when re-assembling it 😳 When unweighted the wheel ran fine (and didn’t look particularly off centre), but obviously when I was pedalling, probably out the saddle, the wheel was rubbing when it flexed. Like I said, idiotic mistake! Now that I’ve put the washer on the correct side of the hub there’s plenty of clearance on both sides.

Another bike maintenance lesson learned!

A gritty wet rotating tyre causes a huge amount of damage in a very short time; I’ve seen a deep groove in a titanium stay caused in just a few minutes.

The tube only carries 50% of the general stress. The tube is only, say, 20% damaged. The damage is a smooth area so less of a stress riser than a sharp cut would be. I would fill it with Araldite and carry on riding. If it broke I would then pay to get the whole tube repaired.

I was gonna say I’ve done the same thing running 25mm tyres in a frame that came with 23mm, then I saw the pic. Looks like Pac-Man has been at your bike.

If you’re getting repair quotes, give HQ Fibre a bell, they did a good job at a reasonable price on a similarly deep bit of cable rub for me on a previous carbon frame.

Talk to Rob Hayles at Re-Carb, he’ll sort it right out. No way I’d ride it in its current state.