1974 Kawasaki 500cc H1-RW Grand Prix

1974 Kawasaki 500cc H1-RW Grand Prix Racing Motorcycle

1974 Kawasaki 500cc H1-RW Grand Prix Racing MotorcycleThe ex-SIDEMM (Kawasaki France)

Prior to Dave Simmonds’ World Championship in the 125cc class in 1969, Kawasaki had made little impact on the international Grand Prix scene. That all changed in 1970 when the factory made available a racing H1-R version of its fearsome 500cc three-cylinder two-stroke roadster: the Mach III or H1. Claimed to produce 75bhp, the H1-R race engine was carried in a tubular steel duplex loop frame equipped (initially) with drum brakes at both ends, the front being a double-sided TLS unit. Following a good showing at Daytona in March, the H1-R was well represented on the grid when the European Grand Prix programme commenced in May. H1-R riders Bill Smith, Martin Carney and Christian Ravel all finished on the podium during the year but the best performer was Ginger Molloy, who scored four runner-up places to finish 2nd in the World Championship behind MV Agusta’s Giacomo Agostini.

Like the roadster it was based on, the H1-R was not the best handling machine in its class, and for 1971 Dave Simmonds had his rebuilt around a Ken Sprayson-designed frame. The result was a transformation: Simmonds scored Kawasaki’s first premier-class Grand Prix win at Jarama and ended up 4th in the World Championship despite missing four rounds. Meanwhile, in the USA, Daytona 200 winner French Canadian Yvon Duhamel was grabbing the headlines riding factory prototypes of the Formula 750 version, the H2-R, which he took to its first victory at Talladega that year. Following Dave Simmonds’ tragic death in at Rungis in 1972 when he sustained fatal burns in a caravan fire, Kawasaki withdrew its official support from Grand Prix racing. The works team would not return until 1975 but in the intervening period the factory did offer limited help to favoured private or importer teams.

For the 1974 season, Kawasaki developed a new 500cc racer, the H1-RW, which despite the ‘W’ appellation remained air-cooled. The machine was essentially identical to the 750cc H2-R, albeit with smaller diameter frame tubes and six gears (privateer H1-Rs had only five). Only two were made, both being sent to the French Kawasaki importer SIDEMM for use in the 500cc World Championship. SIDEMM’s riders were Frenchman Christian Léon and Yvon Duhamel. Léon achieved a few top-ten results over the course of the ’74 season while Duhamel did not participate in all the Championship rounds, preferring to concentrate on Formula 750. With the arrival of the water-cooled Suzuki and Yamaha two-stroke fours, not to mention the latest development of the four-stroke MV Agusta, Kawasaki’s air-cooled triple was simply outclassed. The factory did build a water-cooled 500cc triple that works rider Mick Grant put to good use in the UK, winning the Isle of Man Senior TT in 1975, but its participation in Grands Prix was at an end.

The two 1974 H1-RWs remained with the French importer until the early 1980s when Xavier Maugendre, SIDEMM’s proprietor, sold his company to the factory to create KawasakiFrance. At the same time, the machine offered here was sold to the Cotte brothers. The Cottes did nothing with the Kawasaki and subsequently exchanged it with an Italian collector, who in 2010 sold the machine to ex-racer, Hubert Rigal. It was then fully restored by one of KawasakiFrance’s former mechanics (Giancarlo Perico) in time for the 2011 Coupes Moto Légende in Dijon. A list of the work carried out, which included rebuilding the crankshaft and fitting new pistons, is available. Safety concerns enforced the substitution of replica wheels for the original Morris magnesium items, the original Ceriani front forks and front brake master cylinder being replaced for the same reason. The fairing too is a replica. At the 2011 Coupes Moto Légende, the Kawasaki was tested by Hubert Rigal and then ridden by Yvon Duhamel himself. Interviewed afterwards, the Canadian star said: ‘Yes, it’s a nice bike, in fact a great job was done on the bike, it’s very, very good, it’s just me who didn’t go fast enough…’