Carbon Repair - Is my frame fixable?

[jannmayer]

I dropped my chain when downshifting on my road bike, and it got sucked between the chainring and chainstay. It wedged in there sideways and put some deep gouges in the carbon (after tearing off the aluminum protection plate). I suspect the damage is worse than just the gouges because there are some hairline cracks in the finish nearby, suggesting that it flexed quite a bit, and it fails the tap test.


I'm reaching out to Canyon to see what they will do for a crash warranty, but I'm curious as to whether damage like this would be repairable using a carbon repair kit.

[carbonazza]

My gravel had  this kind of marks for years.
Hit a coin around and in the area, if the sound is kind of the same you're fine.
If it is muted, it is cracked.
Chain stays at the thickest parts of the frame.

[jannmayer]

I already did the coin test. It did sound muted, so I think the game is deeper. 

[carbonazza]

Bummer 
You mean on the nearest mark from the BB?
I would sand around it to see better what it looks like.

[RDY]

I dropped my chain when downshifting on my road bike, and it got sucked between the chainring and chainstay. It wedged in there sideways and put some deep gouges in the carbon (after tearing off the aluminum protection plate). I suspect the damage is worse than just the gouges because there are some hairline cracks in the finish nearby, suggesting that it flexed quite a bit, and it fails the tap test.


I'm reaching out to Canyon to see what they will do for a crash warranty, but I'm curious as to whether damage like this would be repairable using a carbon repair kit.

Canyon should warranty this.  Because the aluminium protection plate should be bonded well enough to stop this.  It looks like it was just stuck on (over the paint??) with some glue though.

[jannmayer]

I'm hoping they will cove it but haven't heard great things about their warranty support. If not, I'll start sanding it down to see if I can fix it.

[Sebastian]

I don't know how Canyon attaches that plate. But I've seen it on other frames where it really is nothing more than a very thick sticker. So I can see how a chain would rip that off easily.

As for the damage itself. If Canyon refuse to help you, first thin I'd do is sand off the paint to assess the amount of damage.
The chainstays close to the BB are a high stress area. Not sure I'd attempt a DIY repair there.

Before you try, you can always get a quote at one of the many carbon repair shops and see if the cost is worth it to you.

[agomezda]

It looks like a 300€ epoxy repair. Do not get worried about the sound, material being removed with the chain but not yet sanded, can mute the coin test.
A posibility is to ride the frame off road, jump and so on until it really breaks and then claim to Canyon or if it passes the test, sand it, reglue a metal protection and enjoy...
I had a very similar one in a Canondale Synapse, same story, mateal part went away and I touched the carbon, was never an issue. I inspected after every ride for months and at the end re-glued a new metal cover.
Finguers crossed.

[badIuck]

Your frame has no problem just keep riding it. All my mountainbikes have marks like this eveywhere after some time.

[abedfo]

I would just give the area a light sand, then a few protective coats of clear nail varnish to seal it. Then never think about it again.

[ExclusiviteChinoise]

I had a nice crack in the middle of my top tube, if you want to fix it the "right way" you apply epoxy + a carbon fiber laminate, you can buy DIY repair kits, you get 2 bottles one with the resin and another with the hardener, you need some compression tape to help squeeze excess resin and make it almost a pro job, then after few days of drying just sand the excess resin and ez like new

[Sebastian]

I had a nice crack in the middle of my top tube, if you want to fix it the "right way" you apply epoxy + a carbon fiber laminate, you can buy DIY repair kits, you get 2 bottles one with the resin and another with the hardener, you need some compression tape to help squeeze excess resin and make it almost a pro job, then after few days of drying just sand the excess resin and ez like new

Same here. I successfully repaired the broken seat clamp area on my VB 218 frame (see the VB218 thread). The frame was replaced by VB under warranty. So I thought I'd give it a go.
Only thing I would add is that I did actually make sure that the fibres I used for repairing actually had the same tensile strength and e-module (elasticity) than the T700/T800 that the frame is made out of. The shop I ordered this stuff from had many different fibres, weaves and densities on offer. So it took a bit of time to do the research and understand it all.

That being said, I would probably never attempt to repair a fork steerer or a handlebar myself. The seat cluster is now holding up fine. I've been riding the frame for around 1000km. No issues. I still haven't painted over the repaired area to be able to inspect it every now and then.

[FHS]

Hopefully Canyon honors your warranty but, if not, I'll second third and fourth what everybody has said about sanding and inspecting for damage. I'd be surprised if you found cracks. The responsible person in me says go see a professional for inspection and repair, but, having done some home fiber carbon repair with a $90 usd DIY kit off Ebay, I can say it's not something that requires tons of skill or lot's of specialty equipment, especially around the area you'd be repairing.

Here's about the most complete, start to finish,  DIY job on a chainstay anybody would need to do.

[jannmayer]

I talked to Canyon and they wouldn't do anything with the warranty. According to them, the chainstay protector is designed to shear off and absorb some of the energy, which it did. (There are a couple of dents in the metal piece.) They wanted $1600 for a crash replacement frame, which is quite high. (I paid about $2100 for the whole Shimano 105 bike.) I would have gone with a Carbonda or Velobuild frame instead if it wasn't fixable.


I sanded the area a bit to get a better look at the carbon, and I spent some more time tapping it. There did appear to be a crack running vertically from one of the gouges, and it sounded different right there.


I decided to have it fixed professionally, and I'm glad I did. I went through Moment Bicycles in San Diego, and it ended up being only $180 to fix it and match the paint, and it took less than a week. (The cost was only half of the initial quote!) The paint match is nearly perfect and you can't see any difference when the cranks are back on.


I though about fixing it myself with one of those kits, but for the money I'm glad I didn't. I could not have gotten it nearly as smooth or matched the color, and it probably would have taken me longer with all that I have going on now.

[Sebastian]

Great! I think you made the right choice. And also good that you kept this frame out of the landfill. Enjoy riding it!