We’ve already covered the histories of the main players in the first 15 years of the four-stroke MotoGP championship but those smaller characters that have dipped in and out of the series are just as vital in its enduring success.
In this fifth part we’re looking at Kawasaki – a company that never quite managed to hit the right notes in MotoGP but which has perhaps had the closest connection of all between its road and race machines. Does the latest ZX-10R’s winning streak in world superbikes owe something to the unloved and unsuccessful MotoGP machines?
Gestation of the ZX-RR
After rumours in 2000 that Kawasaki would return to MotoGP in the four-stroke era, the company made an official announcement in early 2001 that it was to build a prototype for the new championship.
Initially, the firm released only a stylised sketch of a possible race bike, revealing the ZX-RR name but giving away nothing about its technical direction. The company also said it wouldn’t be running in the series until 2003, and would drop its world superbike efforts after 2002 to concentrate on the new MotoGP championship.
Akira Yanagawa was engaged as test rider for the project, and Kawasaki took the unusual step of developing its machine largely in public. The lax regulations of the All-Japan Road Racing series meant that it could compete on a ‘ZX-7R’ that was, in effect, a precursor to the MotoGP machine. First spotted testing in Malaysia in early 2002, the ZX-7 mule went on to race during the year, and gradually evolved into a MotoGP machine.
The chassis, starting life as a ZX-7R, gained prototype thin-walled cast sections at both the headstock and swingarm pivot area. The former allowed air to flow through a nose intake straight through the steering head rather than being routed around the sides as on the ZX-7R. The latter altered the bike’s geometry and rigidity as well as losing the seat supporting structures from the original road bike.
The inline-four engine again started life with its basis in the production ZX-7R motor, but quickly evolved to be a true 990cc prototype, sharing no components with the road bike. As well as allowing more power, the prototype status was required by MotoGP rules which banned production-derived components.
Odd technology initially used on the ZX-RR prototypes included a flat-slide fuel injection setup. Basically it was like a Kehin FCR carb but with an injector hung over the intake trumpet. The idea was similar to the theory behind slide carbs, in that when the throttle was wide open the slide would disappear completely from the intake, leaving a clear tract and allowing more airflow. In contrast, a butterfly always remains in the airstream, even when it’s wide open. By combining the idea with electronic fuel injection the hope was to improve the notoriously tricky part-throttle control associated with flat-slide carbs.
The bike’s GP-style bodywork replaced ZX-7R cowls in mid-2002, appearing at the fourth round of the All-Japan Road Racing series.
At the end of 2002, Kawasaki made the leap to MotoGP, with Yanagawa riding in the Pacific GP at Motegi in October of that year. He crashed, and was replaced by Andrew Pitt for the following rounds (last in Malaysia, second last in Australia, third-last in the Valencia finale.)
The ZX-RR’s effect on production bikes
While other bikes in this series have led to immediately recognisable influences on road-going machines, with the ZX-RR’s conception the flow of influence initially went the other way. The bike was clearly derived from a production ZX-7R in its first form, only to evolve away from the showroom machine as time went on.
Kawasaki never made close ties in terms of styling between its road and race bikes, although there are arguably hints of the original ZX-RR in the 2003-4 ZX-6R’s shape. Of course, the ZX-RR’s inline engine and alloy beam frame were always in the same vein as production models, but direct feedback from the project onto road bikes is hard to point out.
