Exquisite curves and beautiful heat color for that ideal exhaust! Evolving traditional craftsmanship with modern creativity: K-FACTORY

• Z2
• Z1
• Z900RS

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When choosing an exhaust, how many of you pay attention to the "beauty" of the exhaust pipes? There are many different kinds of beauty, but K-FACTORY's manufacturing process pursues the beauty of curves, and their exquisite style has the eye of many a rider.

Titanium full exhausts with flowing curves

When I see exhaust pipes coming out of the 3D bender at K-FACTORY, I get a very strange feeling. This is because the sight of a straight titanium pipe beginning to bend gently, and the different curvatures continuously connecting with each other makes it look like the exhaust pipe has a soul of its own. Of course, you can get an exhaust pipe with this same type of curve if it is hand-bent, although this method is becoming less common these days. However, hand-bending is literally the hand-made work of a craftsman. It takes time and money to mass-produce, and the difference in technique from person to person can affect the exhaust's performance. But when producing a standard machine-bent exhaust pipe, there will inevitably be straight sections created between the curves, and Mr. Hiroshi Kuwahara, the president of K-FACTORY, could not stand for that.

"It may be the trauma of having to settle for a used machine-bent exhaust in the past because I could not afford an expensive hand-bent one. It's easy to make a hand-bent exhaust by repeatedly heating and bending one spot, but only a few craftsmen can make a loose, large curve. Moreover, the thicker the pipe, the more difficult it becomes," says Kuwahara.

From there, he went through a process of trial and error with the help of a bending machine manufacturer in order to develop a machine bending process that would create beautiful pipes resembling hand bending. The first step was to develop a 3D bender to create an ideally shaped exhaust pipe. At a time when bender manufacturers only envisioned bending iron pipes, it was extremely difficult to bend thin, hard, large diameter titanium pipes. That being said, K-FACTORY was able to achieve the ideal curvature, if only after throwing away tens of millions of yen worth of titanium pipe. It took about two years, and the product was finally commercialized in 2001.

More than 20 years have passed since then, but even today, there are few replacement exhausts with titanium pipes that have a continuous curvature. When it comes to exhaust systems, many people may focus on the silencer shape, length, and color. However, K-FACTORY is fully commited to this beauty of the exhaust pipe curve.

"The hard, fat titanium pipes were prone to wrinkles and cracks when bent with a bender, and it took time to achieve roundness. However, at the time, K-FACTORY was also the largest producer of hand-bent exhausts in Japan. We knew that titanium pipes bend differently depending on the material, so we were able to take advantage of our expertise in hand-bending," says Kuwahara.

K-FACTORY was also the first to polish their exhaust pipes and add a blue heat color to them, and now they also offer gold heat coloring as well. Most parallel four-cylinder engines use an exhaust system with a 4-1 merge collector because it has a better sound and is more pleasing to ride.

"The most difficult part is making the exhaust pipes. That's why I really wanted to make this shape. You'll never get tired of looking at it, and just seeing it on display makes you want to own it," says Kuwahara.

These exhaust pipes are the result of Mr. Kuwahara's persistence. Knowing the background behind their creation makes you want to pay closer attention to the shape of exhaust pipes on various motorcycles. K-FACTORY's exhaust pipes, which curve gently from the engine to the merge collector, evoke an image of smooth exhaust flow while giving a powerful impression by strongly wrapping around the engine, greatly changing the feel of the bike's styling. This is the power of K-FACTORY's full exhaust systems, which are machine-bent to exceed the beauty and performance of hand-bent curves.

Gently curving exhaust pipes as if hand-bent

These gentle exhaust pipes enhance the rounded style of the Z900RS. 42.7mm diameter pipes are used because they look cool. The suspension was also modified significantly: the front forks were changed from inverted to upright, and the rear shocks were changed from a mono suspension to a dual suspension.

■For KAWASAKI Z900RS
CLR-R+ Full Exhaust Round Silencer (with blue heat color) 258,500 JPY
CLR-R Titanium Exhaust Pipe (with blue heat color) 140,800 JPY
CLR Titanium Exhaust Pipe (without heat color) 110,000 JPY

Extra-thick steel exhaust pipe for classic bikes of yesteryear

A full exhaust system in the style of a hand-bent assembly pipe using a very wide steel pipe of φ42.7mm. The air-cooled Z has no radiator, so the exhaust pipe curvature is even larger, and there is less clearance with the front wheel. It gives off a feel of the style and sound of the racing exhausts of the 70's.

■For Z1 / Z2
CSR Full Exhaust 91,300 JPY
CLR Titanium Exhaust Pipe (without heat color) 110,000 JPY
CLR-R Titanium Exhaust Pipe SBL (with blue heat color) 140,800 JPY

You can also choose gold heat color!

This golden titanium full exhaust is quite impressive. The exhaust pipe alone, a CSR (Classic Straight Racing) full exhaust with a very wide φ42.7mm steel exhaust pipe, and many slip-ons are also available for the Z900RS.

■For KAWASAKI Z900RS
CLR-RG+ Full Exhaust Hexagon Silencer (with gold heat color) 291,500 JPY
CLR-R Titanium Exhaust Pipe (with gold heat color): 151,800 JPY

Hand-bent curves using machine bending! In-house 3D bender developed for this purpose alone!

The struggle to master the 3D bender. With the help of bender and pipe manufacturers it took two years of trial and error to commercialize these pipes. However, the know-how cultivated through hand-bending was useful in determining the timing of pipe bending and the speed and direction of pipe extrusion.

Compared to steel, titanium is harder and thinner, and therefore prone to wrinkling and cracking. However, K-FACTORY has successfully developed the technology for beautiful bending.

Welded while rotating on an original electric turntable. Incidentally, when manufacturing exhausts, the dimensions of the stock exhaust are first measured, and then the original design is made.

Producing beautiful curves and performance with machine-bending that exceed that of hand-bending

Excess oil and dirt adhering to the polished pipe is degreased, and the pipe is then heated with a burner to give it a heat color. This process requires skilled techniques because the color of titanium pipes changes depending on the temperature and the way heat is transmitted. As the blue color is further heated and the temperature is raised, it changes to gold.

Necessary parts are produced in-house and high skill level is needed to produce them out of hard titanium. The merge collector parts are welded automatically with a combination of various machines.

The bending of the pipes is done by machine, but the assembly process is done entirely by hand. The full exhaust systems are formed by the hands of many craftsmen.

High skill is required for welding thin titanium material. Of course, other materials, such as steel and stainless steel and also used to meet users' needs.

Original Source

Provided by K-FACTORY