Carbon fibre – how it's used in bike frames (video)
For most serious cyclists, a carbon fibre road bike is a must-have piece of kit. But the composite material famed for its light weight, high stiffness and crash resistance starts its raw life as threads woven from thousands of filaments, each a tenth of the width of a human hair.
So how is carbon fibre transformed from soft, bendy threads into the tough material used to make high-end bicycle frames? At the 2013 Tour de FranceBikeRadar spoke to Phil White, co-founder of Cervélo, who told us the story behind cutting edge frames such as the US$10,000 Rca. Watch our video below:
Cervelo’s phil white on how raw carbon fibre is turned into high-end bike frames
Video: How raw carbon fibre is turned into a road bike
White explained how various fibres can be employed in different parts of a frame. “Right behind the head tube, where you’ve got to worry about hitting something, or a crash, you want to use a lot of the high strength material; and then on the sides, where you want to stiffen it up, you probably want to use a high stiffness fibre.”
White, who admitted being fascinated by the material since he first came across it as an undergraduate engineering student, also explained how carbon fibre’s properties are manipulated in the layup process to optimise rigidity, impact resistance and torsional strength.
For example, line up all the strands in one direction and the material is extremely stiff but susceptible to twisting, or torsional force. Alternatively, if the strands are placed at 45-degree angles it gains high torsional resistance but becomes very flexible under vertical pressure. “There’s a balance in each tube of what you want at one end of the tube,” said White. “You just have to tailor the layup as you go along the tube.”
Carbon fibre first emerged as a bike frame material at the 1986 Tour de France, when French manufacturer Look introduced the KG86 under Bernard Hinault and eventual race winner Greg LeMond.