Well that is an ugly failure, but I wouldn't think that anyone is going to warranty an 11 year old bike.

I don't see that as a carbon repair and I can't see being able to re-rivet those big holes. My guess would be that the only option would be to put a washer and nut on the inside of downtube. This might be reasonably easy if you have access through the bottom btacket. The easiest option is 1X.

If I tried to repair that myself, I would get a piece of stainless steel and shape it to get inside of the tube with a hammer. I'd drill out the old rivets in the derailleur and use the holes as a guide to drill into my homemade backing plate. Then I'd unbend a metal coat hanger and hot glue the plate to the end. I'd push it down the seat post until it lines up. With help from a friend I'd rivet the front derailleur through the bad carbon holes and into the backing plate I made. If that failed, I'd set it up with 1x.

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http://www.sfuelsgolonger.com

I would use the original plate and drill holes in 2-3 different areas. I would river it back on, and use a good structural adhesive or JB Weld behind the plate. Wait overnight and you should be good to go.

So this exact failure happened to me under almost the same circumstances (starting uphill big ring under very high standing load…realize wrong ring, try to shift down…everything locks up and chain snaps) 2008 cervelo soloist.

At that point the bike was 9 years old and I couldn’t be bothered with warranty etc (where the hell is the receipt?) especially considering maybe some fault was mine. So my repair is as follows:

-light sand/rough up on contact area
-drill out holes for rivets one size up
-rough up contact side of aluminum
-two part epoxy back in place and install larger rivets.

It’s been fine for almost 5 years now, I don’t have a problem riding it but definitely wouldn’t sell this bike.

Ironically I am thinking of sanding it down and making a lighter tubular 1x so will likely remove it in the spring.

Cheers,
Maurice

I'd call Calfee Design and see if they can fix it.

If they can't, I'd investigate moving to single speed.

There seem to be more and more carbon fiber repair options. I would think for something this simple it would be great to have one take a look at your frame. Where are you generally located? If you have to ship it then the cost of that probably exceeds a small repair.

If it was mine I would just do what Maurice outlined above. I have a rivnut tool and I'd use that and wouldn't have to drill out the hanger base itself.

Since there is minimal damage to the carbon fiber, I'm going to attempt to go the rivet nut route... roughly using this process as a guide: https://www.youtube.com/...b_zbIedQ&index=1

I'll post back after I get all the tools and parts.

I ended up using m3 aluminum rivnuts prepped with alodine and alumniprep, and bonded with araldite 2015. Aditional araldite 2015 was added behind the front derailleur mount. The original mounting holes were slowly sanded by hand with a diamond hand file. I also needed to replace the front mount with a new once since the old was so bent out of shape from the force. Finally I replaced the cable -- the old one was frayed thrashed.

Tools & parts I used:

• Alodine: https://www.aircraftspruce.com/...pnpages/09-01628.php
• Alumniprep: https://www.aircraftspruce.com/...pnpages/09-01621.php
• Araldite 2015: https://www.amazon.com/...dt_b_product_details
• 5mm hand files: https://www.amazon.com/...uct_details&th=1
• 10mm hand files: https://www.amazon.com/...uct_details&th=1
• Hand rivet nut kit: https://www.amazon.com/...dt_b_product_details
• M3 Aluminum rivet nuts: https://www.amazon.com/...uct_details&th=1

Photos of the process and end results are attached.

More pictures: