Carbon and other fiber reinforced composites.
- Composites are a mixture of two materials. The fiber reinforced composites consist of thin long fibers that determine the strength and rigidity of the material and a carrier that glues the fibers together in the desired shape.
- Carbon composites consist of different types of carbon fibers which are mutually connected by a thermosetting plastic carrier. Usually this is epoxy, polyester sometimes. In attendance is carbon fiber with thermoplastic synthetic resin as a carrier, so that the production process is considerably simplified.
- Carbon fibers are, in terms of pure characteristics both in terms of strength and rigidity superior to steel and aluminum. For an equal weight, and the same outside diameter will be a tube made from a carbon composite theoretical 7 times as rigid and strong as a steel tube. Carbon composites have a number of disadvantages which makes these high values are not met.
- The carbon fibers are to be taxed only to tensile. As a result, the fibers should be laid in multiple directions in order nevertheless to obtain a sufficiently strong structure in all directions. The epoxy also has mass, but does not contribute to the strength and stiffness. Carbon fibers can not plastically deform but break abruptly when they are overloaded. Because this brittle fracture is much more dangerous than plastic deformation, frames of carbon composite are build with larger safety margins.
- While carbon composites in terms of strength and stiffness are superior to metals, the large-scale application will, for the time being still have been delayed. The material is expensive and frames are difficult to produce through mass production. Frames with tubes of carbon composites and aluminum lugs are for that matter more favorable to produce and easier than the frames are made entirely of carbon composite.
- Because of the design freedom with carbon fibers, constructors can create frames which are made entirely from carbon composite in every way or be formed so that they have a minimal air resistance.
- In addition to carbon, glass and aramid are also used as fiber material. Glass would be strong enough as a construction material, but has a much lower stiffness which it is not used as a frame material. The properties of the fibers may vary greatly by brand.
- Aramid fibers have higher strength and a lower rigidity than carbon fibers. Therefore, they are used in combination with carbon fibers. The carbon fibers is to ensure the rigidity while the aramid fibers mostly absorb the impact load.