Carbon fibers, also called carbon graphite, have high tensile strength and are very strong for their size. Actually, carbon fiber might be the strongest material there is. A wheelset made by carbon fibers is highly chemically resistant and have high temperature tolerance with low thermal expansion.
But do you know the whole manufacturing process of making a carbon wheel? How to make those fiber pieces into a high-end wheel?
This article will demonstrate the birth process of carbon fiber wheels.
The process for making carbon fiber wheels is part handworked and part mechanical. The raw material is drawn into fibers and then heated to a very high temperature.This process is called carbonization and leaves a fiber with high density.The fibers are washed and stretched to the desired diameter.
After carbonization, those big fibers will be cut into long slices, they are the embryonic form of a carbon rim.
Slices of carbon fiber will be piled up one by one on a circular mould and glued by liquid epoxy resin (a special glue used for high polymer materials ) . To make a standard carbon bicycle rim, usually it needs 18-21 layers of carbon fiber to achieve a high strength and hardness but light in the meanwhile.
Less carbon fiber layers will cause a weak structure, while adding too much carbon fiber means increasing a rim's net weight, which will not be welcome by users. After all, carbon fiber always stand out for its light weight when comparing with other materials.
Step 4 High-temperature Pressing By Machine
This is a vital procedure for making a carbon rim come into being. Put rim moulds into an oxidation oven temperature ranges from 392°F to 572°F (200°C to 300°C).
High temperature and pressure are very important in this procedure, as the layers of carbon fiber are extruded in the oven, the carbon fiber slices will be sticked to each other tightly without any space.
The process of extruding is also a process of increasing strength and hardness. Besides, the glue used in Step 3 will be squeezed out too. After pressing, we get a semi-finish carbon rim .
Step 5 Drilling Spoke Holes
This is not a easy procedure that can be concluded just by three words. Before drilling, holes' size, interval and drilling angle must be counted without any error, otherwise, it will influence spokes' position and tension, which result in a defective wheel.
Step 6 Polishing
Rims after drilling are with a rough surface and edges. Polishing them is necessary and the last step of manufacturing a carbon rim.
Step 7 Testing
Every rim will be put into a series of test before selling, include tensile test, torque test, loading test and braking-bearability test, every test is operated with industrial standard EN14781 and EN14764, because every test concerns safety factor of a wheel!
Step 8 Assembling Rims Into Wheels
To build a rim into a wheel is not an easy job that is always considered as only three basic steps-- inserting all spokes through a hub, lacing them to a wanted pattern (radial or cross), screwing nipples tightly.
As spokes support your weight and transfer power from the hub to the wheel, so its tension and torsion are two main factors of influencing a wheel's performance.
To make sure a wheel is with its perfect condition for usage, a mechanic need to tune and test every spoke repeatedly till get an ideal figure.
Editor: Wendy from Vcycle