Not all carbon is the same
To achieve the best possible performance, the carbon frames of our ROTWILD bikes are modular. This allows us to optimally tune the frames according to the loads that occur at the different points.
The starting materials are so-called prepregs
Prepregs, semi-finished fiber products in which the individual carbon fibers, some of which are up to 0.007 mm thin, are pre-impregnated with epoxy resin (matrix), serve as the starting material for this. Prepregs are always used in the production of carbon parts when maximum performance in the composite area is required. They have a wide range of applications, and carbon prepregs are used in aircraft construction, the automotive industry and in the construction of high-end mountain bikes. The term prepreg is derived from English and is the abbreviation for "preimpregnated fibers", which is generally translated as "pre-impregnated fibers". The perfect impregnation of the fiber with epoxy resin enables high-performance fiber composite components to be manufactured using this process. Incidentally, we only use prepregs from the Japanese world market leader Toray.
Carbon mats with different properties
Manufacturers such as Toray develop carbon mats with different properties. The combination of fibers with different thicknesses and the specific orientation of the carbon fibers in the prepreg create fabric mats that differ in terms of their density, strength and elasticity. These different fibers are used in the production of our frames in order to achieve the best performance according to the loads that occur at the different points.
HT fibers (Torayca T700S)
A fiber with high strength and excellent processing properties for the precision winding process. Due to its structure, the fiber does not twist and is particularly suitable for high-strength applications.
HT fibers with increased tensile strength and stiffness (Torayca T800S)
A fiber with high tensile strength specially developed for weight savings. It has excellent tensile bonding properties.
HT/HM with very high tensile strength and stiffness (Torayca T1100G)
The high-strength high-modulus carbon fiber (HM fiber) solves the challenge of combining high strength with low weight. This is made possible by a new sintering technology from Toray that enables fine control of the fiber structure at the nano level. The result is a significant performance improvement over other carbon fibers. When producing a component, fewer plies are needed to achieve the same stability when using the HM fiber. The reduced wall thickness thus leads to a weight advantage.
Fine tuning in frame building
The layup plan for frame construction defines which fiber types are used for each frame. This describes exactly which carbon mats are inserted into the molds, where they are to be inserted, and with how many layers. According to predefined requirements regarding tensile strength, impact resistance and total weight, the exact combination of fiber types used is determined. The new T1100G-HM fibers are more complex to manufacture than the other fibers and are therefore more expensive. They are therefore primarily used in the carbon frames of the high-end model series. Currently, these are the ROTWILD models R.X750 Ultra and all EMTBs of the R.X375 and R.E375 series.
Erfahren Sie mehr zum Thema Carbon Verarbeitung in den folgenden Beiträgen: How is a modern ROTWILD frame created? und Know-how: Visible carbon structure on the biker frame.