Cracked Carbon Fibre Seat Stay

Stop buying plastic bikes would be my suggestion. I caught a GoPro in my Titanium seat stay in 2014. GoPro mashed. Ti seat stay? A slight dent...

It's definitely the kind of thing you'd notice when cleaning it. Did you not clean it for a while?

as others have said, it's a simple repair job, especially s it's in the middle of the seatstay (easy to wrap carbon over a large area and the middle of the tubes have the lowest stress on them anyway). I had a frame done by cfr bikes and it's still going strong 3 years later (cracked all the way around the top tube), cost about £120.

You can do it yourself, it's not too hard. Sand off all the paint for most of the length of the tube, coat the unpainted area in a thin layer of epoxy, then wrap 2 or 3 layers of carbon fibre (3k is a safe bet) around the tube, dabbing epoxy onto the cloth between each layer. Stagger the edges of the layers to make it look neater. Then vacuum bag it and leave it to cure

Mine also cracked when the rear deraileur got caught up in the wheel and hit it.

The repair was arranged and handled through a local bike shop in Clitheroe and was  £150 for a straight repair job with no paint finish. Very happy with the result and would have no worries about it, strong as ever.

Repairable. Around 200 quid + VAT

http://www.carbonbikerepair.co.uk

What is it with seatstays cracking anyway. Mine cracked over a month ago. Like you I was cleaning it and spotted it. Everyone said my kid must have done it, or something form the garage must have fallen on it. No kids or garage. 

I would love to know how mine got cracked, really would. Bianchi weren't interested in my warranty query in any case. 

I read a case in the US where a stick got picked up from the road, caught in the spokes and spun round so hard that it smacked and cracked the seatstay. Not sure if that's urban legend or not though. Guess could happen considering the amount of miles done per day. 

Anyway, here's what I've learned. Mine was cracked on three sides, but not all the way through, so basically still pretty much intact. Now I'm not suggesting you do this, but.. I tried some tentative rides, and it was fine. Then harder rides. Also fine. Gun it like a boss now, still fine.

Clearly at some point it'll explode, but if you're stuck, you should be fine. Seatstays mustn't take much stress I guess.

I'm not repairing mine yet because I want to ride my bike while weather is decent. Soon as winter project is finished I'll ship mine off for repair and full respray (want a custom paintjob cos my frame is uber-boring).