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A Quick Understanding of Carbon Fiber In Bicycle

Carbon fibers are fibers composed mostly of carbon atom,5–10 micrometres in diameter (diameter is 1/50 of hair). 

1544342776135946.jpgcarbon fiber section.jpg

Carbon fibers advantages :High stiffness, high tensile strength, light weight, high chemical resistance, high temperature tolerance and low thermal expansion. These properties have made carbon fiber very popular in aerospace, civil engineering, military, and motorsports, along with other competition sports.

4 Major Carbon Fiber Manufacturers in the World :Toray(Japan), Toho(Japan), Mitsubishormosa(Japan), Formosa Plastics (Taiwan).

What is 1K/3K/12K/18K means?

"K" refers to a bunch of carbon fibers with thousands of single filaments. 3K means 3,000 single-filament carbon fibers in a bunch of carbon fibers. 12K means 12,000 single-filament carbon fibers in a bunch of carbon fibers.

carbon fiber finish  3K 6K 12K.jpg

Carbon fiber weaving method

1,Woven Fabric
  • Advantages: good-looking, high interlaminar shear stress
  • Disadvantages: low strength, expensive (weaving need cost)

Small K carbon fiber price is more expensive. Normal carbon rim and frame only the surface layer use woven fabrice like 1K,3K,12K,18K.


2.Unidirection Pregreg (UD).
  • Advantages: high strength and stability,layup angle can be designed, and the price is cheap
  • Disadvantages: carbon fiber is not visible after forming

Unidirection Prepreg carbon fiber.jpg

Differences between T300, T600, T700, T800, T1000
These are the carbon fiber models of Toray (Japan).
Carbon fiber tensile strength T300<T600<T700<T800<T1000
However, the smaller the price, the more expensive the K number is, the proportional relationship, the strength is not very much related to the weaving method.

Note: The parts of the frame that use 1K and 3K carbon fiber also have the outermost surface appearance material.


Tensile Strength & Tensile Modulus 
  • Higher strength means product can bear more tensile force.
  • High modulus means product hardness will be greater.
  • T700, T800, T1000  are carbon fibers for more strength.
  • M35J, M50J, and M60J carbon fibers more modulus.
Carbon fiber modulus is 3 times that of Glass Fiber,and 2 times that of Kevlar Fiber.

T800 is high in strength and  M60J  is hight module, but it is absolutely impossible to use only T800 or M60j on carbon bicycle.

So,A  comfortably bicycle must have use both T-series and M-series carbon fibers.

The cost of  carbon fiber.
T800 price is about 3 times that of T700.
Not company made T1000 carbon fiber sport products, because T1000 is a high-tech defense control product.

How to produce carbon fiber prepreg.


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