How Durable is Carbon-Fiber? | Answers

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Carbon Dating **
Is there some info about the durability of the carbon-fiber some manufacturers use on their bikes? I'm not talking about "cosmetic" items, but major components like swingarms from Bimota, forks from Confederate or fuel tanks from Ecosse. I mean, rocks from the road can break them, or "light" falls could have consequences that wouldn't happen with steel or aluminum. I've seen carbon-fiber getting old and fragile on bicycles. So, how durable are these super-light components?
**Cesar M.
Austin, TX

_Willie Amaradio is the owner of Lightspeed Performance Products (www.lightspeedcarbon.com). Lightspeed makes protective carbon-fiber accessories, not major components, but he has done research into manufacturing frames and swingarms. _

_“With carbon-fiber the durability and strength has to do with the design of the part and the manufacturing process,” he says. “The nature of carbon-fiber is that it doesn’t fatigue like a steel part that flexes repeatedly, and then breaks. If you stay under the load threshold for a part it is fine and if you reach that threshold the part fails. It is unlikely that rock chips are going to bother a part, but crash damage might. _

_“The lifespan of a carbon-fiber part doesn’t have much to do with why we don’t see more swingarms or frames. Carbon-fiber is exceptionally rigid, and as we have seen with the switch from steel frames to aluminum, more rigidity is not always a good thing. To switch to carbon-fiber would require a whole new learning curve that would involve the whole bike, all the way to the tires. Considering the costs involved in manufacturing carbon-fiber parts, it doesn’t make sense to switch when current metal designs work so well.” _