Carbon fiber is a revolutionary material that is as strong as steel with a fraction of the weight and Bont has been producing carbon based footwear since 1989. The material is mainly comprised of carbon atoms that are bonded together and aligned to form the long axis of the fiber. Several thousand of these fibers are twisted together to form a yarn which is then in turn woven into a fabric. We source our carbon exclusively from the world’s #1 carbon manufacturer, Toray of Japan.
There are three main carbon weaves that you will see used in the manufacture of cycling shoes. They are:
3k plain is a tightly woven carbon that is used in the aircraft industry and is what we use in Bont shoes.
Unidirectional is what we use inside shoes like the a-one to make them extremely stiff. The benefit of unidirectional carbon is that we can choose which direction we want to lay the carbon and we can produce extremely stiff, light weight shoes using it.
This is a cheaper form of carbon that is not as strong as 3k and is around 20% cheaper.
In the old days, if you bought a plastic or nylon based shoe, you knew what you were getting. But now-a-days, with all these modern expensive materials, it's getting tougher, so here are some ways that manufacturers use materials that you need to watch out for.
- One layer of carbon: When you buy a shoe and you see that it has a carbon base, chances are that only the outer single layer is carbon. Under that carbon layer can be an injection molded plastic or nylon base or a fiberglass base.
- Unidirectional carbon: You see unidirectional carbon printed on a variety of shoes, however, many of them use injection molded carbon in the plastic and call this unidirectional carbon. We feel that this is a misuse of the terminology. For us, unidirectional carbon means carbon fiber material where all the strands travel in the same direction.
- Silver fiberglass: A number of shoes use a plastic injection molded base, with some carbon particles in it and a single layer of silver fiberglass for the outer layer. They are allowed to print ‘carbon’ on the base because there is carbon dust in the plastic mold under the fiberglass but the fiberglass woven material on the outside is certainly not carbon. Carbon fiber is always black.
- 100% composite: This term covers anything basically… The question you need to ask is… a composite of what? Usually it is a nylon fiberglass composite that you will find in shoes.
- Monocoque: A monocoque shoe is one where the carbon has been directly laminated onto the liner. Some companies are jumping on the monocoque band wagon and calling a carbon shell with integrated heel cup a monocoque shoe. It isn’t.