Inside the New Hagane Build: SUZUKI KATANA Custom by TG-RUN

TG-RUN's KATANA

TG-RUN’s “Full Metal Hagane” is a high-quality complete custom bike based on the air-cooled KATANA. From the moment the new liquid-cooled Suzuki KATANA was released, shop owner Sugimoto declared his intention to build a new version of the Hagane using the same approach. And in spring 2020, the “New Hagane” finally came to life.

“The concept is the same as it was for the original air-cooled Hagane,” explains Sugimoto. “We take the stock bike and eliminate anything that feels off or lacking, making it into a better machine overall. For the KATANA, that means correcting the riding position so you can properly shift your weight onto the chassis. We also reduce the visual and physical weight of the rear section. Then we add a street-legal (in Japan) full exhaust system, to bring out smoother power delivery and reduce weight. And the stock tires also felt a bit rigid and lacked suppleness, so swapping them out was part of the plan too.”

To kick things off, Sugimoto spent a lot of time riding the stock KATANA to reconfirm that it had a solid foundation. However, he felt the triangle formed by the seat, handlebars, and steps made it hard to apply body weight effectively, so he refined that layout for better control.

That included a TG-RUN top bridge paired with the stock handlebar but lifted slightly and pulled back using risers. A newly developed step kit shifted the footpegs slightly rearward to improve control—so well-positioned that there’s no need to reposition your feet except when actively shifting weight. The seat angle was also revised to create a more natural, comfortable sitting posture. Together, these three parts transformed the bike’s feel—instantly making it more inviting and enjoyable to ride.

The suspension, wheels, and brakes are made up of Ohlins front forks and rear shock, Marchesini forged aluminum wheels, and Brembo Racing calipers with a Brembo master cylinder.

“This is the usual RUN package,” says Sugimoto, “but I use it because I know how good the results will be with this combo.” The suspension was tuned for all-around performance, based on Sugimoto’s own specs. He even had MotoGP rider Nobuatsu Aoki take the bike out for a ride in the city, and Aoki gave high marks not only to the suspension but to the overall ride quality. The tires were swapped to BRIDGESTONE RS11s to improve feel and soften the ride compared to the stock setup.

As for engine tuning, the only thing done was replacing the exhaust system with a K-Factory CLR-RG+ full titanium system with a hexagonal silencer. This alone gave the bike smooth throttle response from low revs and a high-quality exhaust note. Without modifying the engine itself it offers both character and ease of use.

The KATANA is known for its design. Sugimoto took time to truly understand the bike, not just by riding it himself, but also through selling the new model and related training sessions. From that experience, he identified what was missing and added only what was necessary to create his ideal version: the New Hagane. The result is a refined custom that feels completely natural to ride, free of any abruptness or awkwardness. This package also connects seamlessly with the rider, turning the idea that “quality is enjoyment” into something you can actually feel. It’s a build that goes beyond the KATANA itself, serving as a model for how to approach modern motorcycle customization.

Handlebar

The TG-RUN top bridge, compatible with stock forks, raises the handlebar position slightly and pulls it closer to the rider for a more natural grip and better forward visibility. There’s also a steering stem kit available for those using Ohlins forks. The front brake master cylinder is Brembo Racing, and the clutch holder is from GALE SPEED.

Bodywork

A visor windshield 15cm longer than stock and its base, made of twill-weave carbon, are Magical Racing parts made for the KATANA.

This original seat dramatically improves rider control, comfort, and reach to the ground through changes to the inner foam and outer material. Customers can bring in their own seat base and choose the upholstery type and color.

The fender eliminator kit is a one-off TG-RUN part. The tail cowl and other bodywork are painted in “Hagane Silver” to evoke the image of a sword blade, the same as their well-known demo bike, GSX1100S Full Metal Hagane. Paintwork was done by Arataka Design.

Engine

The engine and frame remain stock. Only essential add-ons like a radiator core guard and frame sliders have been installed.

Intake & Exhaust

The titanium K-Factory exhaust system (CLG-RL model with hexagonal silencer) is finished in a special Hagane color. It delivers refined, easygoing characteristics while contributing to weight reduction. This is the only engine-related modification.

Chassis

The TG-RUN rearsets kit offers 5 adjustable positions for a more connected and secure riding feel.

Ohlins inverted forks are combined with Brembo Racing 4-piston calipers and SUNSTAR discs. Bolts were upgraded to 64 titanium from Beta Titanium.

The forged aluminum Marchesini M7RS wheels are finished in custom “Metal = Hagane Silver” and sized 3.50-17 front, 6.00-17 rear. Both front and rear carbon fenders and the chain guard are from Magical Racing. The rear suspension is an Ohlins shock with stock linkage. The drive chain is from RK, sized 520.

Gallery

Specifications

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