As if catastrophic failure was a likelihood for a reasonably well engineered and mass-manufactured carbon frame.
If there’s an issue with the unbranded frames it’s most likely that they aren’t engineered that well, use cheap carbon, and hence aren’t as stiff and light as they could be. Alternately, “seconds” would most likely have blemish in the gel coat or some such.
Given the price difference between cheap carbon and good carbon, I imagine these folks are just using the molds they have to build up the cheapest carbon frames they can to reasonably decent quality standards. They’re likely really good for the price (I’ve read as much), but unlikely to be nearly as good as a frame with a well-engineered layup.[/quote]
Sorry this is long, but this is complicated.
I’m not asking you to believe me, I’m passing on what one of the top ten bicycle carbon fiber engineers in the world said. Just passing on info from a dude who left the company he founded because they kept pushing him to go to lighter over safer.
This was also verified by Mr. Yamaguchi, who - believe it or not - hand-made the first generation of carbon bike frames for the USA Olympic team. He told us stories of having to glue patches on the frames between runs because the bikes were cracking and splitting down the middle (this was pre-monocoque) during heavy sprints. He kept up on the manufacturing side of things, could tell me which plant makes bikes for which brands, etc. He said ‘good carbon is very very good, cheap carbon is scary’. He was very impressed with my Giant OCR.
Great carbon is ridiculously strong. Hell, at my fattest I’m almost 3 bills and I ride a carbon roadie and the Mojo, one of the first carbon FS mountain bikes. I have no problem with carbon if done right, so no FUD from me.
Carbon bikes are like a cake, mushed together in a mold and ‘baked’ and the nature of the material hides flaws to the naked eye. You could get a first-rate knock off, or you could get one with a mushy left chainstay and a void at the head tube junction. You just can’t know because of the process. With metals, you can often see the significant dings that could lead to really bad stuff later. The way carbon damage propagates, you need a friggin’ X-ray.
Carbon frames are like silicon chips - make a ton of 'em, cull the batches with too many flaws, and charge enough to cover the waste. Those dirt-cheap frames are quite often the culled ones. Just like chips, good silicon gets thrown out because of a few bad wafers, good lots of carbon frames get remaindered with the bad. Sometimes, in China they’re a third-shift run by guys at another factory who stole the molds (google Kuota to get some juicy stuff on that) and do their own knock off.
If it’s Taiwanese plant, your odds are good. I wouldn’t get one from China, though, the rep I’ve heard from people that source stuff from factories there is they make great stuff when you watch over them every step of the way, but when your back is turned you have no damn idea what’s going on.
They also basically have slave labor and can’t be sued, so if you lose your teeth on one, tough shit. An American-based company with a lot more to lose overbuilds and overtests the shit out of these things. (Well, Giant and Trek do. Scott are super weight weenies and I wouldn’t throw a leg over one if I was over 150.)