Getting Carbon frame repaired?! Broken rear wheel stay.

As it's a seat stay the risk from a repair failing is less life threatening than if it were a repair to a fork or head/down tube. I'd have a laugh and buy a carbon repair kit to have a go at fixing it yourself and keep it as a winter bike. It's fairly easy to do a solid and safe but not massively pretty repair.

It's a Canyon Ultimate, yes? With no sentimental value and, even after being repaired, much reduced monetary value.

Stick the whole bike on eBay. Someone will buy it either to repair, or for the components. Repairing it, assuming you are honest when it comes to sell, will add barely any value, as there are very few people who would risk a repaired third-hand frame from eBay.

When you've got shot of the broken bike, buy a new one from Canyon, enjoy that "new bike" feeling, and don't ever mount it on a turbo trainer.

I know the guys at Target Composites, and I know they have some pretty high tech kit for checking frames out for hidden damage, and the repairs & paint matching he does is fantastic. Fairly standard job for them, so I'd not worry about the repair at all - whether it stacks up financially is up to you of course, but to reply to some of the above, I'd certainly be getting it looked at first before just binning a frame you seem to be pretty happy with otherwise.

Ive used my carbon cyclocross bike on a turbo for nearly 5 years.  It hasnt broken.  However I have heard of the odd failure, but its extremely rare.  I understand the extra stresses if you try and mimic outdoor power riding-standing up trying to rock the bike.  

In my quest to improve my indoor experience I built a full length rocker board, which does allow rocking motion and has I suspect lessened frame stresses.

Carbon fibre is extremely strong in longitudinal direction, but easy damaged under side impact where its vulnerable.  Just gently squeeze a top tube with your hand feel it bend.  Thats why in high stress areas the lay up carbon fabric layer is rotated 45 degrees to increase multi directional strength.  Tubes could be made thicker walled ,but would offer less ride comfort and add weight.

Personally I would scrap frame and rebuild bike onto new cheap carbon frame or even go for another material.  I like steel or titanium more these days

Put it on eBay. Some idiot will underestimate the repair and overpay...maybe. Worth a shot.

 “The £400 odd quote above is on the upper price end for a seat stay repair, I'd guesstimate more like £250.”

The other £150 will be used up trying to match the scrapes, scratches and general wear and tear to the paintwork to make the repair look invisible! 

PP

I suspect that your frame was damaged before you sat on it a bit hard and heard a crack. 

And if you'd not been hard on it, it's logical that it would have been damaged on a trainer. If I were Canyon, I'd not warranty race or lightweight bikes used on trainers either. I can only imagine the force being put through the seat stays by a big guy sprinting. 

However that's totally repairable and a very common fix for a carbon repairer. A decent repairer will let you know of any other damage also. The £400 odd quote above is on the upper price end for a seat stay repair, I'd guesstimate more like £250. 

I think what concerns most of us is not whether the damage can be repaired...it is the fact that such a simple and soft impact caused it in the first place.  Then, even with a short ride, there would have been a lot of very unusual stresses on the other areas (particularly the other seat stay which is the bit that would be a concern given the location of this break).  

So, more about the damage that cannot be seen rather, than the simple fracture that can be seen/fixed.

At the end of the day, this is one for the OP to decide on.  Hindsight will dictate the right choice in the end.

Carbon can usually be repaired. It's one of its advantages as a material over alloy or welded (not brazed) metal frames.

Please let us know what the carbon repair companies say.

Try @re_carb in Manchester. I've seen him repair far worse than that, you'd never know it had been broken.

I'd say the stresses of mounting the bike on a turbo is likely to have created that stress point, all you did was give it the final knock.

I'm with the others, probably the softest way to crack a seatstay I have ever heard of. I would bin it, buy a replacement and swap everything over.

If that lets go descending a bumpy hill or in a left bend with oncoming, you could be history.

Please get advice from a specialist.

Manufacturers aren't keen on carbon frames being used on a trainer, I'd guess because it stresses the seat stays. See https://road.cc/content/feature/216681-it-okay-use-your-bike-turbo-trainer

I'd bin it and sell the parts, or bin it, strip it, and find  a new carbon frame (PlanetX currently have the Pro Carbon for £400, or the team-issue Holdsworth Super Pro for £500). That way you get to build your bike up, don't have to wait for a repair, and it's brand-new with a guarantee. Vs what, £3-400 for a repair where you're without your bike for a while.

That sounds a seriously soft way to break a frame. No way would I trust that frame even after a repair.

Unsure what Canyon's viewpoint on turbo trainers is but it could be that usage that led to the crack.

I reckon £300 to £400, but don't take my word for it, send the same photo to carbon bike repair in surrey, (or someone more local to you) and let them give you an estimate.

I've seen grubbier frames, it's what tends to happen if you ride every day.  It's repairable by a specialist company but you need to consider if it's going to be worth it taking into account the age of the bike and its general condition.  How did it break?  Did you respect the weight limits?  You may have overloaded the other stay and caused internal delamination, without ultrasound/X-ray it won't be possible to tell.  That costs $$.  Or the previous owner may have crashed it and there may be other weak spots, there's no telling.  One of the reasons why I'd never ever purchase a used carbon frame.

Did it crack under the weight of the dirt?   

Looks repairable to me...

Have you contacted canyon to enquire about a replacement frame?  When the frame of my words specialized bike cracked on the head tube (aluminium) they replaced the bike, which was 10 years old