Ideal curvature leads to smooth exhaust! Dress up your bike with the perfect curves!

• Z2
• Z1
• Z900RS
• ZEPHYR1100

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The theme of this article is the beauty of curved lines in exhaust pipes. The roots of K-FACTORY's craftsmanship lies in their attitude of never giving up in the pursuit of this ideal shape. What is the background behind their creation of such elegant exhaust pipes, which were said to be impossible to make using machine bending? Let's find out!

Seeking the beauty of curves beyond the limits of machine bending...

The pipes for the exhaust systems sold by K-Factory have no straight sections. The titanium pipes are drawn in large, constant curves as if they are being sucked into the merge collector. Different people have different obsessions, and Hiroshi Kuwahara, the president of K-Factory, has a genuine obsession with exhaust pipes. Exhausts are the biggest part of the customization process, so ever since he started K-Factory, he has been infatuated with creating beautiful exhaust pipes.

No other machine bent pipes can be found with such a soft curve, and that is because the technical skill necessary is very difficult. As you can see when you look at a stock exhaust pipe, normally machine-bent exhaust pipes are made using a combination of "curve -> straight -> curve," and few of them have a constant curvature. Until the 1990s, the only exhausts that were beautifully bent with continuous curves were hand-bent.

"When I was young, I longed to have a hand-bent exhaust, but they were very expensive and I couldn't afford one. So I had to put up with machine-bent, and used at that. Perhaps because of that trauma, I have always wanted exhaust pipes to have beautiful curves and have been pursuing that shape ever since. Even with hand bending, it is relatively easy to make a pipe by heating one part, bending, and repeating that process, but only a few craftsmen were able to make a loose, large curve. Moreover, the thicker the pipe, the more difficult it became. We had to remake our pipes over and over in order to achieve that beautiful form I was looking for. I wanted to create an exhaust pipe that you would never get tired of looking at, and that would make riders yearn to own when they saw it displayed," says Kuwahara.

Let's compare the curve to the stock exhaust pipe!

What could only be called infatuation resulted in beautiful full exhausts!

Back in the day, racing exhausts were all hand-bent. They were literally produced one by one by craftsmen who filled the pipes with sand and heated them with a burner. However, when the bender, a machine used to bend pipes, became popular in the industry, machine bending became the mainstream. But Mr. Kuwahara could not tolerate the curves created by benders, which left straight parts on the exhaust pipes. He wondered if it was possible to somehow produce a hand-bent like curve with machine bending.

It was around 1999 that K-FACTORY introduced a 3D bender. At that time, bender manufacturers could bend steel pipes, but they did not have the technology to bend thin and hard titanium pipes. So, K-FACTORY worked together with the bender manufacturer and underwent a process of trial-and-error. They discarded many pieces of titanium material because they wrinkled or cracked when bent. What came in handy at that time was the hand-bent exhaust technology they had been working on to create beautiful exhaust pipes. At the time, K-FACTORY was the largest manufacturer of hand-bent exhausts in Japan. Therefore, they were well versed in what kind of materials bend easily. After two years of development, the result was a full exhaust system with a buffed exhaust pipe and blue heat-colored finish.

The hand-bending process by craftsmen certainly produces beautiful curves, but there is always a margin of error in measurements that may cause a difference in performance. With machine bending however, there is no need to worry about such a problem. In the end, machine bending was able to achieve a level of curvature and performance that exceeded that of hand bending. This is all due to Mr. Kuwahara's undying desire to create the most beautiful exhaust pipe. The thick, yet gently curved exhaust pipe flows as if wrapping around the engine. The more you look at the details, such as the clearance with the front wheel and cylinders, the more you can feel Mr. Kuwahara's determination.

Beautiful curves come from 3D benders!

K-FACTORY exhaust pipes have no straight sections!

For KAWASAKI Z900RS

CLR-R+ Full Exhaust Round Silencer (JMCA certified, with blue heat color) 258,500 JPY
CLR-RG+ Full Exhaust Hexagon Silencer (JMCA certified, with gold heat color) 291,500 JPY
CLR-R Titanium Exhaust Pipe (Racing part, with blue heat color) 140,800 JPY
CLR-RG Titanium Exhaust Pipe (Racing part, with gold heat color) 151,800 JPY
CLR Titanium Exhaust Pipe (Racing part, without heat color) 110,000 JPY

Hand-bent merge collector styling that blends in with the Z of yesteryear

For Z1 & Z2

CSR Full Exhaust (Racing Part) 90,300 JPY
CLR Titanium Exhaust Pipe (Racing part, without heat color) 110,000 JPY
CLR-R Titanium Exhaust Pipe SBL (Racing part, with blue heat color) 140,800 JPY

Air-cooled large-displacement engines can show off the beautiful curves even more!

For ZEPHYR1100

Full Exhaust, Single
Semi-order From 214,500 JPY
CLR-R Titanium Exhaust Pipe SBL (Racing part, with blue heat color) 140,800 JPY
CLR Titanium Exhaust Pipe (Racing part, without heat color) 110,000 JPY