I’ve noticed a vertical crack on the seat tube of my carbon frame, likely caused by overtightening during routine maintenance.
Due to the design, I can’t just replace individual components—probably the entire frame or even the bike would need replacing.
What do you think? Is this the end?
Most importantly, is it safe to ride?
by FedeCata
8 Comments
I think it’s not a very forgiving design. But many modern frames have similar issues.
Trek have (or had) a crash replacement warranty. You likely wouldn’t get a free frame but might get 30% off.
This looks like the perfect place to engage a carbon repair tech.
But since it is a hollow tube, you also have the opportunity to make a repair yourself by adding a bunch of material to the inside. It would add weight, but if the option is to scrap the frame, it’s worth a shot. I would lay up a bunch of layers of carbon and epoxy around a cut and tied off piece of inner tube. Slide the mess inside the seatpost (use a small dowel in the wrapping to help slide it down, then take the dowel out while inflating), inflate the tube, and you will have a nicely compacted new inner layer of carbon. You could even do this a few times to build it up and I would extend it several inches below and to the top of the mast. For belt and suspenders, put some playdoh in the tube as a stopper and fill it solid with epoxy afterwards and you won’t ever be able to crush it again.
Good carbon shop will fix it for ya. If you ask them, they even reinforce.
DYI is an option, but if you have zero experience and have no vacuum pump I would not risk it. Eating asphalt is not a fun thing to do 😀
Shouldn’t be that expensive as well
I think that frame is done.
Maybe you could sleave another tube inside to add support but it would have to fit tight so it doesn’t fall down the tube and/or it would have to extend all the way down to the BB, but then it would be contacting the shell insert and that could present other issues, such as creaking from rubbing against the insert.
https://preview.redd.it/l8eins5pd0be1.jpeg?width=1125&format=pjpg&auto=webp&s=d7be076a7a21c0bbc1df56b8ec89f5caa903d907
You have a Trek so yes you are cooked
i would not ride anymore, i see couple of this snapped already, but i also fixed many of this is not complicated….
Repairable, take it to cf frame builder