Revolutionary Retro: SUZUKI GSX1100S KATANA Custom by Wonder Product
Wonder Product's GSX1100S KATANA
Until the anniversary model was released in Japan in 1994, many GSX1100S Katana customizations were not so much modifications that stood out, but rather extensions of the stock styling. Keeping the unique style and coloring, the engine, which was already thought to be sturdy enough, was simply souped up from 1074 to 1135cc and given a new carburetor. The suspension was originally slim but the bike has a square aluminum swingarm, so it was common to replace the rear shocks, or change to 18-inch front and rear wheels using stock parts from the oil-cooled GSX-R1100 series. This Katana by Wonder Product, customized around 1993, retains the stock form of the Katana as much as possible, while adding a windshield with an integrated headlight cover and original paintwork that gives it a strong sense of individuality, fully bringing out the custom look. However, it is not only the flashy appearance, but also the meticulous care that went into each part that is worth noting.
The front forks are an inverted type made by GCB with a unique configuration in which the shock-absorbing function is provided not inside the fork tube but with a separate unit. The special upper and lower fork brackets that activate the separate damper as the forks move up and down were remade from machined 7075 aluminum before being installed, as the GCB ones are made of magnesium. From this we can see that even 30 years ago, Wonder Product's approach has always been to use more reliable, more precise, and stronger materials so that their custom bikes can be used properly on a daily basis. The wheels are cast MARCHESINI hollow three-spoke, and the front brakes consist of Performance Machine (PM) 4-piston calipers and ø330mm floating discs. This is the same combination used on AMA superbikes at the time. The rear brakes also feature a PM 4-piston caliper to achieve both good looks and performance. A closer look reveals that the fuel tank cap is an aircraft type, and an air bleeder has been added to the front of the tank. The paintwork, commissioned to the late Mr. Shibata of Wonder Staff, one of the best custom painters in Japan at the time, was based on the image of a fighter plane and included carbon stickers, gold leaf, glitter, and other techniques. The shop's customization philosophy is reflected in every detail, making this bike a true "full custom" in both appearance and workmanship. At the same time, it served as an example of the level of freedom that could go into a Katana customization.
Handle
The windshield doubles as a headlight cover. At the time, it was a show of skill to find rare foreign parts to match the bike you were customizing. The handlebars were converted from clip-ons to a bar type, and the top bridge, handlebars, and clamps are all gold. The clamps are FZX750 stock, and the gauges and mirrors are stock with an oil temperature gauge added. The GCB front shock mount can be seen underneath the top bridge. The front master cylinder is an AP Racing CP3125-2.
Bodyworks
The paintwork combines a fighter plane-esque pattern with a metallic blue almost glitter base color and a flare design. The SUZUKI logo is applied in gold leaf, which was rare at the time.
Engine
Although the engine was disassembled and completely reassembled for a fine-tuning that also served as an overhaul, the inside is almost completely GSX1100S stock, including the 1074cc displacement. The only thing not stock is a YOSHIMURA cam chain, installed for better durability. The carburetor is a Keihin CR Special φ33mm, and the exhaust system is a Vance & Hines Stainless Steel Megaphone. The subframe is an OVER Racing special aluminum type, and reinforcements were added to the frame itself.
Chassis
The steering damper is mounted parallel to the oil cooler with a newly made linkage under the stem. This is a part that is not seen from the outside but enhances functionality. On the right side of the photo, you can see the front shock unit which is separate from the fork tube. You can think of it as a mono suspension.
The swingarm is a stock GSX-R series aluminum square type with an added lower sway bar. The front and rear wheels are MARCHESINI cast 18-inch, and the rear shocks are by WP. For the brakes, the front uses Performance Machine (PM) varying diameter 4-piston calipers + ø330mm discs, while the rear also uses a PM 4-piston caliper and disc. The inverted front forks are by GCB.
Gallery
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Specifications
Part | Details |
---|---|
Engine | YOSHIMURA Special Cam Chain |
Carb / Intake | KEIHIN CR Special Carburetor φ33mm |
Exhaust | VANCE&HINES Stainless Steel Megaphone |
Frame | OVER RACING Subframe Kit GCB Inverted Front Fork Set (Stem) |
Brake |
AP Racing Brake Master Cylinder PERFORMANCE MACHINE 4 Piston Caliper 125 x 4 PERFORMANCE MACHINE Floating Disc Rotor 330 PERFORMANCE MACHINE Rear Disc Rotor |
Wheels | MARCHESINI M3R ET 2.75-18 MARCHESINI M3R ET 4.00-18 |
Suspension | GCB Inverted Front Fork Set WP VAP Twin Rear Shock |
Original Source of this Article
Heritage & Legends


editor
Hakuyo
A foreigner who rides in Japan, Japanese call this "Gaijin Rider". Third year in the Webike global team. He feels and shares the real bike life in Japan then presents you how interesting Japanese customs are.