1982 Suzuki RG500 MVKII

Engine no. 11841-15400

· Rare square-four Grand Prix contender
· Zero miles since complete concours restoration
· From the Southwest Superbikes collection
· Randy Mamola tribute paint and graphics

As comebacks go, Suzuki's return to Grand Prix road racing in the 1970s could not have gone much better. Out of frontline GPs for seven years, the Hamamatsu firm dusted off its 250cc RZ two-stroke square-four design last used in 1965, enlarged the engine to 498cc, and came up with the successful RG500. As with its predecessor, the compact layout employed four separate geared-together crankshafts driving a six-speed transmission via an intermediate gear. With rotary-valve induction and oversquare bore/stroke dimensions of 56 x 50mm, a maximum output of 90hp at 10,500rpm was claimed.

In 1974, Britain's rising star Barry Sheene, winner of the previous year's FIM Formula 750 Championship on a production-based Suzuki TR750 triple, rode his works RG500 square-four to a debut second-place finish in the season-opening French GP. Working through the usual teething problems, he finished an impressive sixth in points that season. In 1975, now with 100hp to work with, Sheene gave the RG its first GP win at Assen. A second victory, at Anderstorp, helped him to sixth in the championship again. In 1976, running a 54 x 54mm bore/stroke and seven-port cylinders, it all came right for the RG500, now fully sorted. Sheene rewarded Suzuki with its first world title in the premier class, then repeated as 500cc champion in 1977. Just as impressive, made available to privateers in '76, the RG500 dominated the overall points standings, taking all 10 top spots that year, and seven out of 10 in '77.

In 1978, the powerplant was revised with twin crankshafts, stepped cylinder pairs—the front lower than the rear—plus a cassette-type gearbox. Power increased to 120-125hp, top speed to 170mph. Chassis-wise, we see the first road race application of Suzuki's Full Floater rear suspension and anti-dive front forks. In this form the RG would win two more world titles, in 1981 with Marco Lucchinelli up and in 1982 with Franco Uncini in the saddle. Before it was superseded by a V-four design in 1987, the RG500 would amass a total 50 GPs and seven consecutive constructer's championships.

Precise details of this 1982 RG500's race history have been lost to time but apparently it was campaigned by a factory satellite team starting in 1983. We do know that it crossed the Atlantic and was raced at the USGP in 1988-89, ridden by veteran AMA privateer Eugene Brown. Some time after, the Suzuki was lucky enough to be acquired by noted U.S. race bike restorer/collector Robert Allen, who undertook a complete, frame-up rebuild. He chose to finish the RG in the 1982 Team HB livery of Suzuki teamster Randy Mamola, 13-time GP winner and series runner-up on four occasions, a fitting tribute to one of the most prolific road race machines ever.

Unridden since its restoration, lately the RG500 has been in the climate-controlled care of the Southwest Superbikes collection.