I've recently acquired a Colnago CT1 knowing that there is a crack in each of the carbon seat stays very near the dropouts. I've been in touch with Calfee, who've been great in detailing what they think the issue is, that basically boils down to corrosion with the dropouts, which can be a common occurrence with CT1's. They've offered to look at it and possibly fix the issue by replacing the dropouts and repairing the carbon, but they may not be able to fix it upon actual inspection depending on the severity of the corroded carbon...





Rather than waiting a potentially considerable amount of time shipping my frame to the US to have it repaired, I was considering simply replacing the entire carbon B-Stay with something like a ready-built rear stay set like the Columbus Tusk rear end kit. Or possibly a Deda Firebox:

http://www.cycle-frames.com/bicycle-fra ... STEEL.html" onclick="window.open(this.href);return false;
http://www.cycle-frames.com/bicycle-fra ... Steel.html" onclick="window.open(this.href);return false;

Since these rear ends are for steel, would they possibly not work with the titanium of the Colnago frame?

If it will work, I assume that the Colnago's carbon rear end can be pulled out somehow and one of these replacement options simply fitted into place with epoxy resin or some such? Any advice would be appreciated.

This is what the end of the CT1 look like connected to the stays:

CT1s seem to break. At least the ones around here have. I wouldn't try the home repair route on anything I'd ride. If you're not in the US, perhaps Calfee could refer you to someone in your part of the world. Otherwise, I'd suggest it's a wall decoration.

Thanks for your advice, but I'd like to investigate replacing tubes before attempting a repair (or getting a shop to attempt a repair).

After looking at the Columbus and Deda complete stay sets more carfully it looks like the chain stays wouldn't be compatible anyway as the CT1 has a 2-piece design straight into the BB shell.

Another option is to simply replace the seat stays - Columbus do an option for this too:

http://www.cycle-frames.com/bicycle-fra ... STEEL.html

The shaping is essentially proprietary, though that may be the same B stay as found on most of Colnago's bikes at that time.

I'd contact Colnago and ask them if it can be replaced or they can supply a new rear end for installation by Calfee.

I managed to replace a single dropout on a carbon rear triangle, but I had to have one custom made for this purpose, it cost a lot and required many hours of work. In case of the CT1, you can only replece the rear triangle if the wishbone has a round profile, or you can manage to get the a Colnago-specific RT. The chainstay stube size also has to match, and since you cannot modify the titanium tubes, your choice is very limited.

The bad news for you is that I have seen at least a dozen discarded CT1s because of this problem - the repair is simply not cost-effective. I know one guy who had TITANIUM RT from another discarded frame (broken at the downtube) welded to the main triangle of a CT, but it did not look very good or safe...

Thanks for that - something to think about. I was given the frame by someone I know for free who didn't want to go through the hassle of fixing the frame, and now I'm seeing why

Nevertheless, I'd like to try getting it on the road one way or another. I guess I'm willing to put a bit of cash into the 'project' since I paid nothing for it, and if this means getting a custom made seat stay that will fit into the titanium sleeve, then I'd like to find out what my options are.

I've measured up the carbon tube of the wishbone and it's completely round - measuring 28mm in diameter, so I believe the Columbus Link seat stay will work... if it's of the same or slightly smaller diameter - I can always use a carbon shim of sorts?

Perhaps I need to speak to someone here in the UK who has experience using carbon, gluing seat stays/dropouts.

Why not try a different tack - have someone in the UK who builds in Ti do the opposite - copy the Carbon section in Ti. Might be more expensive, but might ultimately last longer. Burls do Ti builds as do other builders locally.