Considered as an exotic space-shuttle composite just 10 years ago, carbon fiber is now utilized in nearly every cycle component, from frames and parts to helmets and shoe soles. Carbon fibers are made of carbon, the omnipresent part that forms coal, graphite and diamond and is part of every organic chemical and every life form on earth. Carbon is the fourth commonest part in the universe and the
2nd commonest element in the human body.

Polyacrylonitrile ( PAN ) fiber, also the source material for acrylic fiber, is created into carbon fiber by heating it to acute temperatures, burning away basically everything aside from carbon. The ensuing 5-8 micron ( millionths of a meter ) thick fibers are a tenth the thickness of a human hair and made from carbon atoms strongly bonded together in minute crystals aligned parallel to the fibers axis. Robust and stiff, the fibers have a rigidity index of thirty three million pounds per square inch ( MSI ) and a rough surface. Dear processing can strip off this outer surface to expose a thinner, smoother
Intermediate Modulus ( IM ) fiber that packs tighter with other fibers for higher rigidity per unit area. A more costly processing can create High Modulus ( HM ) carbon fibers, which boasts a Youngs modulus stiffness of 42 MSI to 55 MSI or even more.

Common-modulus fibers are bundled together into yarn and woven into fabric. A number followed by the letter K designates how many thousands of fibers are in a strand of the yarn ( as in 3K, for 3,000 fibers per strand ). Woven fabric often comprises the top layer for aesthetic purposes, but most carbon fibers in a cycle part instead come in flat sheets of firmly packed parallel fibers pre-impregnated with epoxy resin stuck to backing paper. Precisely cut pieces ( plies ) are stacked, or laid up, on top of each other at opposing angles ( typically forty five degrees ), to resist forces from different directions. Unlike metals, carbon fiber plies in the laminate structure can be oriented to create a composite structure that can be stiff in one particular direction and more
Flexible in another. Indeed, plies must be laid up at angles, because carbon fiber, like thread, is robust if you pull on it but far weaker if you push lengthwise on it or bend it sideways. However , in a carbon fiber tire bead, you dont want strength in stress alone, so orienting fibers at angles and gluing them together with resin allows the plies to work together, opposing forces from all directions. Subjecting the laminate to high pressure and heat in a mould pushes out air and excess resin.

Well-engineered carbon composite parts have high stiffness and strength, low density and high fatigue life but low elongation they cannot stretch or bend much before they break. Screw ups come from not properly engineering the directions and kinds of fibers to handle the loads.

To discover the latest in Schwinn Evolution and spinning workout check out http://spinningforfitness.com/

Tags

Health and Fitness