Alan Cathcart rides Barry Sheene's 1975 Dutch TT-winning Suzuki RG500.
Suzuki RG500 XR14
Engine: 497cc liquid-cooled rotary valve 2-stroke square-four, 56mm x 50.5mm bore and stroke, 8:1 compression ratio, 101hp @ 11,200rpm
Top speed: 175mph
Weight: 297lb (135kg)
In 1974, the prototype Suzuki RG500 made its competition debut, raising the curtain on the modern era of 500cc Grand Prix racing by making factory-level Japanese 4-cylinder performance available to privateers for the first time.
It was 40 years ago this year, in the summer of 1975, that Barry Sheene won the Dutch TT at Assen aboard an RG500, claiming Suzuki’s first-ever 500cc GP victory. Before the first 25-bike batch of Mark 1 RG500s went on sale for the 1976 season, the paddocks of the Continental Circus had been packed with a selection of arcane bikes; 4-stroke Italian twins and multis, British singles, and the prototypes of the soon-to-be-supreme Japanese 2-strokes, headed by over-bored 350 Yamahas and the first-generation air-cooled customer 500s, like the TR500 Suzuki twins and Kawasaki H1R triples. Against this transitional group, factory 4-cylinder hardware like the MV Agusta and YZR500 Yamaha had an easy time.
But the RG500 changed all that. Though it’s become something of a cliché to stamp the Suzuki as the Manx Norton of the 2-stroke Grand Prix era, that’s exactly what it was. For a full decade, from 1976-1986, the rotary-valve square-four packed GP grids around the world. To underline the immediate success enjoyed by the eager customers awaiting the bike’s debut, just look at the 1976 World Championship, the first year the production RG500 was available. With 58 bikes delivered to customers, no fewer than the first 12 riders in the final 500cc points table were Suzuki-mounted, including such illustrious privateer names as Agostini, Read and Lucchinelli. It would remain a competitive privateer option right up until the end of the production run in 1990, winning Suzuki seven consecutive 500GP Manufacturer’s World titles from 1976-1982, including four riders crowns in 1976-1977 with Barry Sheene, and two more for Marco Lucchinelli in 1981 and Franco Uncini in 1982.
One man who didn’t have to dig into his pockets to buy an RG was 1976 500cc world champion Barry Sheene. By winning the first of his two back-to-back world titles on his factory Texaco Heron Suzuki, Sheene underlined how dominant the new square-four had become. Sheene won five of the six GPs he rode in that year, finishing runner-up to teammate John Williams in the other one. In the days when only a rider’s best six results counted towards the final points table, it was a near-perfect score. MC
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