The short answer. - written quickly, poor grammer & spelling.
Mancunian Lee said:
i would of thought these where a bad idea considering one mistake and hit the bike at a funny angle and it will shatter into tiny pieces wouldnt it?
No.
Carbon frames aren't carbon, they're a composite of many different materials, and a plastic or resin (like plastic anyway) filler. The outer layer on a good composite frame or component will usually be spectra or rouging or kevlar or SGlass or something to protect the structural carbon below. This is because carbon is indeed brittle, but not like you'd expect. It doesn't "shatter" really. It's fiberous, and when it breaks, it's sort of like breaking a stick of celery, but flakier... anyway. The stresses concentrate at weak areas, much like a weak link in the chain will break first. The stress piles up there, usually causing some damage, making it even weaker, causing more damage, till you have a failure point. Grooves, sharp corners, angles, seams, scratches, anywhere there's an interruption in the surface becomes the weak link, & are called stress risers (the amount of stress rises on these features, see?). There's an entire science behind Notch Sensitivity. It's a big deal. A notch will alligator out till your frame rips open or your cranks crack, or your bars snap, etc... there are ways for this notch sensitivity to become a problem. A big one is galvanic corrosion. Companies who do a quickie job of bonding aluminum fittings & inserts into carbon amaze & delight on the showroom floor. A full carbon Trek for $700! Yippeee. Yes, well, alum reacts rather poorly I'm afraid, when in direct contact with carbon. So this is where frames get more expensive.
A carbon seatpost goes into your frame, and gets pinched by the cheapass slotted seattube method everyone's been using forever. Tighten that skewer or bolt too much, and you'll cause the edges of your slot to indent into the post. That poor little legth of seatpost has to support all the load & impact loading your entire frame has to. Putting a notch in such a critical place is taking the express train to tire-induced friction burn on ass town. Still, everybody does it. Yep, and everybody breaks em too. You just accept it. Seatposts break. Carbon ones doubly so. Frames break too. Same goes for cranks. And frames. The less expensive your carbon frame, the higher the failure rates will be. Doing carbon right takes time, & there's no way around it. Also, typically, the bigger the company, (like the one I work for. Anonymity is grand.) the cheaper their carbon will be, regardless of the sticker price. This is due to a few things, but one very big one, is that when you get very big, there are exponentially more hands in the pie, and keeping your retail price competitive means the cost has to come out of somewhere, and it certainly can't come out of payroll, so you find the cheapest possible way to get the job done, and charge as much as you possibly can for it in the end, and hope that there's a penny left in it for you after the dealers have taken their 40% margin, the reps have taken their 20% cut, the distributors have taken their 30% margin... Welcome to capitalism. We've become a nation of suck-eyed jackyls skimming off the top. But who suffers? The not-I's go all the way around till they find you, sitting in the middle of the trail on a broken pile of carbon slivers and aluminum shards... Price driven markets kill innovation. But in a dangerous sport like this, they kill people. But you people keep buying what we're selling, so as far as we're concerned, money talks, and it's your own damned fault.
Still happy you asked?
