In 1978, the legendary Pops Yoshimura switched from Kawasaki to the mighty Suzuki GS and won everything from the great race at Daytona, to the world’s biggest endurance races and a pair of AMA titles with superstar rider Wes Cooley. Nearly fifty years on, the Kawasaki city-based outfit, Iida Racing Factory, has built its entire business around the big air-cooled Suzuki machines. Like Pops before him, Iida-san is a racer at heart, and what he develops for the track filters its way down to his street riding clients. When it came time to build a new demo bike for his business, he asked the question: can you have the best of both? The answer is this incredible Suzuki GS1200SS, street-legal for ripping up the roads and ready to race and win on any given Sunday.
For twenty years, Iida-san modified and refined his own GS1200SS, spending his weekends operating as a privateer and finding new ways to increase the performance of his big GS. When he opened Iida Racing Factory five years ago, that bike became known in the industry as the company’s ‘Demo’ bike, featuring all the new parts and pieces to come out of the workshop. This year, Iida-san felt it was time to start with a fresh canvas and build ‘Demo-two’, a GS1200SS that would showcase his quarter of a century of experience with these bikes, be a rolling advertisement for his company, and most importantly, be the fastest GS for road and race.
“The No. 2 bike also pays homage to the Yoshimura endurance racers, but it is designed to perform even better. It is made in such a way that it could be taken to Taste of Tsukuba by removing the safety parts.” Iida-san believed two issues were vital to improving the performance of the GS: “For this No. 2 model, the concepts were lightweight and heat countermeasures.” Starting with the frame, it’s all about adding strength where it is needed and removing any wasted weight. A large gusset has been added around the neck, extra bracing pipes are welded into the rear sections of the main frame, and the rear shock mounts are reinforced.
The subframe is considerably shorter than the stock unit, and all of the mounts and brackets are made from lightweight aluminium, with various-sized dimple dies used to remove further unneeded material. The swingarm is based around a stock GS unit, but a very tasty brace has been added to the underside to provide that much-needed lateral strength. The pivot bolt is all new, and along with the Öhlins fully adjustable shocks, the full package for the rear-end transformation is available to the general public. The front end starts with an all-new steering stem and triple clamp package, which is machined in-house from billet blocks of 7075 aluminium.
Dropped through these are a set of Öhlins FF521 front forks, which feature Iida Racing’s own internals. Getting back to the all-important issue of weight, reducing the unsprung mass is key, so a set of O.Z Racing aluminium forged GASS RS-A wheels are fitted, measuring 17 inches and wrapped in street and strip Bridgestone tyres. The braking package is just as vital; the fronts are Brembo’s new GP4-MS finned calipers, which grab a set of Sunstar Works 320mm discs. The rear brake utilises a Brembo GP2-SS caliper and a Sunstar 250mm disc, and all of the master cylinder components come from Brembo too. The final piece for this part of the package is an Öhlins adjustable steering damper for the front end, a must for any bike heading to the track.
The bodywork definitely has that racer vibe, and as Iida-san points out, is hugely inspired by the race glass of Yoshimura. However, there is no fibreglass used here; in the pursuit of more weight saving, it’s all carbon fibre and comes straight from Custom Factory Tokaji, who call it their ‘GS1000R Type Body Kit’. Underneath the carbon shell, the fuel cell is aluminium, the same material is used to make all of the mounts, and the mirrors are Magical Racing’s Type 3 units. To keep that street legal theme going, there is a full suite of indicators, a dimmable front headlight, and a small taillight and number plate bracket.
But the engine is all race; this thing puts out stonking horsepower, and before he even set about building the engine, that issue of thermal management was front of mind for Iida-san. The main oil cooler is massive; it literally looks like a radiator, leaving no room for a secondary unit. Taking inspiration from the Honda RCB of the ’70s, the second cooler is mounted behind the screen, with ventilation via a set of drilled holes. “This has lowered the oil temperature by 15°C.” Knowing he could push the engine even harder while still maintaining reliability, Iida-san began assembling a 1216cc monster. Inside, there are forged pistons from Wiseco, Yoshi cams, and even some lightweight valve train components from a GSX-R750.
The whole engine is assembled with a titanium bolt set, stronger, lighter, and much better than the original items! The bottom end is carefully balanced, and a TSS slipper clutch is a vital addition for a bike that gets ridden this hard. The auxiliary pieces are just as impressive too, with fuelling provided by a bank of Yoshi TMR-MJN carburettors, and the exhaust is a one-off masterpiece made from titanium, producing a hell of a sound. To monitor the vitals, a Stack rev counter is joined by a host of gauges for temperature, air/fuel mixtures, etc., and there is even a Motoscope mini speedo. Iida-san is tight-lipped on the horsepower figures, but the weight is a staggeringly low 176kg, and you better believe this GS can compete with anything in its class – a genuine Yoshi beater.
