Balancing Tradition and Safety: Suzuki GSX1100S KATANA Custom by TG-RUN

TG-RUN's GSX1100S KATANA

The front 19-inch star-shaped cast wheels and two-tone seat, along with a megaphone-end exhaust that extends from the left and right sides, maintain the stock appearance of the KATANA. This is a recent work by Technical Garage RUN, and many components, including the exterior and handlebars, remain stock. However, when pushing it around, it clearly feels lighter. So we asked Mr. Sugimoto about the kind of order he received and how it was executed. "The order was to maintain the stock appearance as much as possible. Some people may think, 'If that is the case, just leave it as stock,' but it would be difficult to enjoy riding the KATANA now." Normally, it would seem that a thorough restoration, including an overhaul of all parts of the machine, would be sufficient. Even for this bike, the frame, exterior, and wheels are still stock, but everything has been cleaned up and repainted. All short parts that might deteriorate in the future have been replaced with new ones, and everything has been reset.

"Even if you've installed new parts on a stock bike, suspension and brake concerns won't disappear. The reason is that the bike is 40 years old, and even the Final Edition (2000 SY) is now 20 years old. Based on that, there are points where riding it seems dangerous. Think about it. Even if you have the power to cruise at 200 km/h with room to spare, dealing with sudden accidents or unexpected problems becomes challenging. Handling this is the responsibility of the rider who understands it's an old bike. Specifically, let's talk about the brakes first. The master cylinder, calipers, rotors, and pads should be replaced to ensure braking power. For this bike, all of these have been replaced. Naturally, the front and rear suspension capacity will be insufficient, so this area should also be addressed. The rear shocks have been replaced, and the front forks can be either replaced or, as in this bike, they can be overhauled and replaced with new springs, and the oil level can be adjusted. Ideally, radial tires should be used for braking power and suspension performance, but they aren't available for the stock 1.85-19 size wheels. Therefore, newer generation tires should be chosen. Grips are also essential; here we are using Bridgestone BT46s. The bottom line is that crucial safety parts should be of a new generation and reliable. This ride is an example of that." It may sound strict, but it considers safety and peace of mind. As mentioned earlier, replaceable parts were replaced and refinished, and the bike was reset. Likewise, the torque of bolts is properly managed using a torque wrench. This may seem obvious, but it's often overlooked. "The titanium exhaust in the shape of KATANA stock was released by OHNO-SPEED at just the right time, so we added that to the mix as well. The stock bike is heavy, putting a lot of stress on the brakes, which can be greatly reduced, as well as the load on the suspension and engine." This was another reason for the lightness felt when pushing the bike around. In hidden areas, chromoly shafts are used for the front and rear axles and swingarm pivot, and the engine hangers are originally machined from aluminum by TG-RUN to give the chassis a firmer feel. It's worth noting that these modern updates have been made while maintaining the stock appearance of the bike.

Handle

The cockpit is built in accordance with the order to maintain the stock appearance as much as possible. On the right, above the top bridge, the Final Edition serial plate can be seen. The handlebars are stock forged clip-ons; the front master cylinders have been changed to Brembo Racing, and the brake lines have been replaced with stainless steel mesh, which are some of the few changes.

Bodyworks

The fuel tank is a new one that was stocked at TG-RUN, and the rest of the exterior and frame have been repainted. The frame refresh is necessary to take advantage of the front brake reinforcement and front and rear suspension modification/settings, both of which are essential to the KATANA. Reinforcement is not necessary unless the bike is to be used on the race track.

The seat is replaced with the TG-RUN Sport & Comfort Seat, which features new internal foam and rider-side upholstery while maintaining the stock changeover pattern and upholstery color. The new seat provides better legroom, comfort, and maneuverability. A pillion belt is also included as a stock appearance feature.

Engine

The air-cooled DOHC 4-valve (2-valve, 1-rocker) 1074cc straight-4 engine was in good condition and had low mileage. Therefore, it was left in stock condition and cleaned up externally. The lower engine hanger was also replaced with a TG-RUN machined aluminum mount kit. Additionally, the stock BS34 carburetor was retained.

Intake & Exhaust

The 4-2-1-2 OHNO-SPEED GSX-S Maniac Exhaust System is a full titanium reproduction of the stock exhaust system, including the tapered silencer and end section, as well as the same left-right layout as the stock exhaust. The system is lightweight, weighing only 7kg compared to the stock 18kg, and the noise-reducing material is replaceable, making the system suitable for long-lasting use.

Chassis

The steps are from the TG-RUN original step kit for GSX1100S KATANA, with the bar position moved 3mm upward and 5mm forward for better maneuverability. The swingarm pivot shafts are now made of chromoly, along with the front and rear axle shafts, to give the chassis a more solid feel. The stock engine hangers, which are made of steel plates, have been strengthened with the "TG-RUN Billet Engine Mount Kit for GSX1100S KATANA" to provide high-quality handling.

The front forks are stock φ37mm with new springs and oil level settings. The front brakes are the "TG-RUN Caliper Support & Racing Disc Set (for GSX1100S KATANA Final Edition)" with Brembo Axial billet calipers. The discs are Sunstar Racing Discs, ø310mm.

The rear suspension is a stock KATANA Aluminum Swingarm + Ohlins Shock, and the rear brake is a stock 2-piston caliper + stock disc. The wheels are repainted stock cast 1.85-19/2.50-17 size. The drive chain is RK525XXW (ed. gold) converted from the stock 630 size.

Gallery

Specifications

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