Carbon fiber bicycle industry in China has been a mixed bag, T300, T500, T700, T800, T1000 and other exaggerated propaganda techniques emerge in an endless stream, but the domestic media carbon fiber bicycle manufacturing field is exactly a blank. This time, BIKETO was fortunate to contact Huizhou Kangsheng Composite Material Technology Co., LTD. (hereinafter referred to as KSC) for a full section, and strive to let you know how a big brand OEM is to produce carbon fiber bicycles.

I would like to thank Vice President Shen Zhong (left) and General Manager Zeng Jianjun (right), who have been making carbon fiber for more than 20 years, starting with simple golf clubs and moving to more advanced bicycle racks.

Not all materials called carbon fiber are suitable for the bicycle industry. They are too rigid and easy to be brittle. Super-rigid materials are like glass, which will crack on impact. Therefore, a good design must have a suitable carbon fiber material formula with both rigidity and strength. If you want to lightweight frame, you need to match high-strength materials and ultra-rigid reinforcement to match appropriate frame performance. The FIBER in the picture is SPREAD TOW FIBER imported from Sweden (in essence, it is a kind of carbon fiber material, but it is made by special preparation and pressure, and it is ultra-high pressure sheet fiber). Because of its very high price, KSC is the only manufacturer in China that really applies and mass-produces it. At the same time, it is one of the main materials of the world Formula One racing car, the same rigidity and strength of Toray T800 carbon fiber only a quarter of the weight and thickness!

Before any good frame is developed, it must first pass international tests (CEN 14781,14766 & CPSC). Various strength, rigidity, fatigue and impact tests are essential. All frame tests in KSC factory are carried out based on EN and CPSC standards. Felt and other international brands (top 10 brands of Tour de France team) were all manufactured at KSC in accordance with the professional testing standards and instruments of EN and CPSC, all of which increased by at least 20% over EN standards! Some brands sold to the US market also need to pass CPSC testing standards, and some more demanding brands will require their products to pass the most stringent German testing standards (EFBE & BIKE MAGAZINE TEST). All these are the premise of product quality assurance.

Static testing procedure. In order to ensure the quality, KSC Felt mountain bikes were made in accordance with the EN14766 standard plus 20%.

KSC's test instruments are regularly maintained by specialized personnel, which is more rigorous than many other factories.

Even the torque wrench is imported to ensure accuracy.

The frames used for testing in regular OEM factories are painted white to make it easier to see if there are small cracks. And the tested frames are not allowed to be sold and must be destroyed. (So the "factory goods" you buy from various channels are defective products or test products). The picture shows the Felt time racer made by different internal molds.

The test standard of the front fork, various directions and forces are unavoidable. Each test has its own technical indicators.

Carbon fiber and glass fiber, almost in every carbon fiber factory will be used, the difference is only the use of the place. KSC also has a glass fiber production workshop, from silk to prepermeated cloth are carried out in KSC. According to Zeng's introduction, carbon fiber is mainly structural material, and glass fiber is insulating material and imitation material. The finished glass fiber cloth will be wrapped in the joint position of carbon fiber and metal parts. Because carbon fiber is a conductor at a certain temperature, electric ions will corrode carbon fiber to some extent, so a small amount of glass fiber is needed for insulation in these joint places in the production process. Another use of glass fiber is before forming, the interface of the air bag needs to be wrapped with glass fiber to increase its sealing effect. However, this part of glass fiber will be removed afterwards, which is necessary on the premise of not reducing the performance of the frame.

There is a corresponding SOP for each individual operation, and it is well illustrated for workers to understand.

France Vactor digital cutting machine, only 2 sets in the country. It is used in the cutting of carbon cloth of high-end frame. Conventional cloth cutting costs more material and the transition of carbon cloth corners needs special overlap and shape to deal with. Therefore, this machine must be used for high-end ultra-lightweight frame and high-end materials.

This white stuff is EPS inner mold, also only used in high-end bicycle frame inner mold, because each inner mold can only be used once, the production cost is very expensive. (Readers can pay attention to the details, the workshop is equipped with a special trash can, waste materials are uniformly thrown into the trash can for disposal. This is the attitude of first-line foundries.)

Different brands of molds and molds of different sizes have independent placement positions, can not be confused.

 

All over the shop there are Sops and different materials.

The performance of the frame is greatly affected by the way the carbon fibers are stacked. Many fake manufacturers claim T1000 materials (only two in China actually have this Japanese material), but why such a big difference in performance? In fact, every part of the frame needs to be stacked Angle, material, the number of layers need to be calculated through rigorous. You can see the positions of the five channels, at least five different angles and different levels. (The standard of a good carbon fiber processing plant depends more on the technology of carbon fiber stacking and rigorous testing standards.)

 

The process of entering the mold. Every time before entering the mold, the hard workers must clean the mold before moving on the high temperature mold, to ensure that the frame has no impurities. Next, workers need to put a layer of plasticizer on the mold to help the molded frame better peel off the mold. The process of entering the mold of only one frame takes nearly an hour to complete. In other words, a mold of such a production line can only produce 10 frames a day. This is also the reason why some carbon fiber frames are sold at 20,000 or 30,000 yuan.

The components of the mold are almost all too tight together, and every stroke requires a hard worker to hammer in.

The process is the same, in order to ensure accuracy, the pre-tightened parts need to be knocked out.

 

Even the front fork brake mounting hole is too tight, the master body of the hammer can see the heavy work.

The front fork Felt, the way it looked when it came out of the mold.

Guess what this is? Felt the rectifying cover of the rear clip for the time trial frame.

　　Pork floss? Of course not. This is the original marbling, in fact these UD, 3k, 12k and marbling, the difference is just the finishing material, the weight and performance is almost the same.

Before painting, the frame needs to be dusted to ensure the smooth surface of the paint.。

High precision processing of five parts, take the hand will need some force to assemble, visible its accuracy is not general.

Front fork offset check, each front fork needs to spend at least a few minutes of inspection and correction here, to ensure that the factory products must be qualified.

 

　　Workers scrape the burr on the connecting rod with a knife, and wipe it with alcohol afterwards to ensure the smooth turn point after assembly and the smoothness of the paint surface. Each connecting rod has taken workers a lot of time to deal with.

Details make or break a business. Readers will find that all the workers at KSC's carbon-fiber factory must wear gloves, that waste is stored in a trash can, and that high-precision torque wrenches are made in Japan. And the workers in front of the sealed furnace use vernier calipers are with dial.

　The production of carbon fiber frame is a kind of patience. Why not use electricity? Why not use a heavier sandpaper? Why not use large pieces of sandpaper? In addition to raw materials, than are careful.

The labeling process of handlebars and seat bars Felt was carried out in an independent closed workshop, with the door closed every time in and out to prevent the influence of sand and dust on the labeling quality.

Dust-free water label workshop. Each labeling process is done here, and individual frame codes need to be affixed after this last inspection.

In order to ensure the correct Angle of the front dial mounting seat, the workers need to adjust the mold in advance

This is a crystallization of high-end materials combined with advanced carbon fiber stacking technology and high-precision mold. Four advanced technologies are applied:

1, material science and technology: the application of Japan TORAY ultra-high tonnage 30T/40T/50T/60T fiber matrix structure, and combined with Sweden sheet STF fiber, and anti-impact 5T carbon fiber

2, digital cutting, tailor-made optimal aerospace grade structure cutting technology

3. Internal pressure 3D molding process of hollow EPS integrated shell mold

4, continuous fiber integrated coil, the traditional lapping method further reform

This is the same process as the Formula One carbon fiber car (RED BULL).

That's how the 700-plus road car Felt was born. (Don't forget, this is a product 20% higher than the EN standard, which is qualitatively different from a knock-off product that focuses on weight and ignores product safety).