Carbon fiber has been used in bicycles as a high-tech material in the last ten years. Strictly speaking, carbon fiber is not a simple carbon element, but a mixture of carbon element that is bonded and reinforced with epoxy resin after weaving. In the early days of carbon fiber, the epoxy resin used would even decompose in the sun due to technical reasons. With the advancement of technology, the shortcomings of this excellent material are gradually being overcome. For example, the German K frame uses high-grade 16K carbon fiber. The strength of this carbon fiber even exceeds that of steel, and it has a lifetime warranty.
Generally speaking, carbon fiber as a bicycle material has the following characteristics:
Very light weight: Carbon fiber road frames of about 1200 grams are already visible everywhere. Since the mass of carbon is only 1.6 g/cm3, it is no longer a dream to make a frame of about 1 kg.
Good shock absorption performance. Carbon fiber can effectively absorb shock and maintain good rigidity. This feature makes it a very good competition-level material.
Frames of various shapes can be made. Unlike the manufacturing process of a general metal frame, a carbon fiber frame is generally made by first making a mold, then attaching a carbon fiber sheet to the mold, and finally fixing it with epoxy resin. This kind of manufacturing process can use aerodynamics to make a frame with minimal wind resistance.
The current problems with this material are mainly the following two points:
Complex stress calculations. The carbon fiber frame is composed of carbon fiber, which is characterized by strong tensile strength but weak shear strength. Complex stress calculations (longitudinal rigidity and lateral rigidity) are required during processing, and the carbon fiber sheets are overlapped and formed according to the calculation. Generally speaking, carbon fiber resists surface impact quite well, but its puncture resistance is very poor. That is to say, it doesn't matter if you fall horizontally and vertically. I'm afraid that you may encounter a sharp pebble or two in the process of falling horizontally and vertically.
The price is expensive. Compared with titanium alloys, the price of carbon fiber frames is even higher. The price of top carbon fiber frames is tens of thousands. This is mainly because the carbon fiber frame manufacturing process requires a lot of manual work, and the scrap rate is very high, resulting in a large increase in costs.