From our Old Bike Archives – Issue 98 – first published in 2022.
Story: Jim Scaysbrook • Photos: Peter Jones, Rob Lewis, Gary Reid, Damian Cook, John Ford, Karel Zegers.
After years of domination by Agostini and MV, development (and interest) in the premier Senior GP class was stagnant. Then, just in the nick of time…
When Suzuki pulled out of Grand Prix racing at the end of the 1968 season, it looked like the end of a story that had begun with the company’s first works entries for the 1960 Isle of Man TT. In fact, with Yamaha following suit and Honda already out at the end of 1967, Grand Prix racing was heavily into survival mode. The days of World Championship domination by Suzuki in the 50cc and 125cc classes with riders like Ernst Degner, Hugh Anderson, and Hans-Georg Anscheidt were over as restrictions tightened on engine design and gearboxes in the smaller classes. Moreover, with costs escalating and motorcycle sales declining, the late ‘sixties were about diversification into other areas such as cars, especially for Suzuki and Honda. Yamaha at least had their ‘production’ 250 and 350 twins to swell the grids, but without works development, were under pressure from the likes of Benelli, OSSA and MZ.
Suzuki had kept a toe in the water through the FIM Formula 750 class in Europe and the AMA Series, and notably the Daytona 200, in USA. The vehicle was the fast but fickle water-cooled TR750, developed from the road-going GT750 ‘Water Bottle’ which adhered strictly to the FIM and AMA rules in being developed from a street design, but as these rules were relaxed, opening the door for Yamaha’s all-conquering TZ700/750, Suzuki lost interest. Post 1969, Suzuki did have a presence in the 500cc GPs thanks to the TR500 twin, itself based on the road going air-cooled GT500, which was further developed into the water-cooled version in 1973. These were built in small numbers, capable of producing results with decent riders (such as Kiwi Keith Turner, second in the 1971 standings), but in reality little faster than a well-tuned TZ350 Yamaha.
Yamaha had also crept back into Grand Prix racing in 1973, with the works 4-cylinder 500 ridden by Finn Jarno Saarinen, with Suzuki’s results coming from veteran Australian Jack Findlay on a series of Suzuki-powered specials. There was no hint of a full-scale return to GPs until late 1973, when news leaked out of an all-new four cylinder Suzuki that underwent its first secretive tests in November of that year. In fact, the concept had its origins in the disc-valve design that came to Suzuki via Ernst Degner, when he defected from East Germany to Japan. Suzuki had fielded a square-four 250 in 1967 and 1968, which showed glimpses of promise but was plagued with carburetion and magneto troubles.
What appeared as the RG500 in late 1973 owed little to the earlier 250-4, being the result of a team specially assembled for the task in Japan. The engine featured four separate crankshafts, with four MZ-style cylinders sitting atop the crankcases. With encouraging results from the test program in Japan, the decision was taken to enter the 1974 500cc World Championship with a team comprising Brits Paul Smart and Barry Sheene entered by Suzuki GB, with Findlay aboard a third RG500 entered by the Italian Suzuki importers Saaid. When the title chase kicked off at the French Grand Prix at Clermont-Ferrand on April 21st, it had a totally new look, with Giacomo Agostini now on a works Yamaha YZR500, having defected from MV Agusta after losing the 1973 500 championship to team mate Phil Read. In the race, Agostini shot to the front and stayed there until a gearbox bearing let go, handing the win to Read. But Sheene was just five seconds behind in second place at the finish, pushing Bonera on the second MV back to third. Findlay’s engine gradually lost power and he finished 12th, while Smart retired, suffering from injuries receive in a crash in Britain the previous weekend.
That second place was however, as good as it got for the Suzuki squad, with Sheene scoring just one other podium and the Suzuki’s suffering from various teething problems. In the final standings, Findlay and Sheen filled fifth and sixth respectively, well behind the MVs and the works Yamaha pairing of Tepi Lansivuori and Agostini. 1975 brought more of the same, with Sheene seriously injured at the Daytona 200 and Findlay forced onto a privately-run Yamaha after Sasid withdrew from racing. Although he missed the first part of the GP season, Sheene again finished sixth in the final standings, with Lansivuori fourth on the factory entry, and John Newbold ninth after taking Smart’s place in the Suzuki GB team. The season did however produce the first win for the RG500, when the brave Sheene, just weeks after his massive crash in USA, defeated Agostini in a classic encounter at the Dutch TT at Assen – both riders being given the same race time but the Brit judged to have been fractionally ahead. Sheene’s second win came in July when he easily beat Read to win the Swedish GP. A retirement at the final round, caused by a design fault that saw a repeat of the failure of the power take-off gear for the four separate crankshafts, cost Sheene dearly, although Lansivuori did put enough placings together to take fourth in the championship.
Then came the bombshell; Suzuki would once again cease direct factory involvement in racing – Yamaha had announced the same decision one month earlier. But unlike Yamaha, Suzuki decided on an alternative strategy. Rather than a full-factory effort, which had cost a rumoured $2.2million in 1975, Suzuki would build replicas of the RG500 and sell them at a heavily subsidised price of just $5,000, thereby ensuring a much-enhanced presence on the grids for 1976. It was a shrewd move, and without it, the premier class of motorcycle racing may well have collapsed overnight.
Filling the grids
The new ‘production’ RG500 was virtually identical to the 1975 machine with the exception of steel-spoked wheels instead of cast magnesium, and the redesign of the troublesome takeoff shaft with larger 8mm bolts holding the two halves together. The rear shocks had been moved from a vertical position to a lay-down format, with the bottom mounting points astern of the rear axle. Initially, a production run of just 25 was planned, but it was soon clear that demand would far outstrip supply, and Suzuki realised that they would dominate the grids in the Senior class worldwide, and stand a strong chance of winning by sheer weight of numbers
The new bikes made their debut at the Indonesian Grand Prix in November 1975, in the hands of Australian Bill Horsman, Kiwis Stu Avant and John Boote, and local Bambang Soedarsono. It was an all-in race, with several works-supplied 750s in the field, and although the larger machines filled the top three places, the Suzuki’s weren’t far behind. Horsman’s machine went straight back to South Australia, where it was unfortunately wrecked in a major crash at McNamara Park, Mount Gambier.
Just weeks later, in January 1976, came the Australian TT at Laverton Air Base outside Melbourne; a meeting that has slipped into history for all the wrong reasons (see OBA 15). Entered were no fewer than eight of the new Suzukis, ranged against Agostini’s MV Agusta. Famously, Ken Blake took the win on Jack Walters’ RG500 after runaway leader Stu Avant crashed his RG500 when the engine seized. It was an emphatic demonstration that the ‘production’ Suzuki had the legs on the previously dominant MV, a fact not lost on Agostini. The news of Blake’s victory spread rapidly, and the clamour for more RG500s was so deafening that the planned production run was tripled to 75. When the first round of the 1976 World Championship lined up in France in April, more than 20 RG500s were entered, with Sheene romping away to the first of three straight victories and ultimately the world title. At the Belgian GP at Spa-Francorchamps, Sheene’s Suzuki GB team mate John Williams led home a complete Suzuki sweep of the top ten places, with a winning average speed of a staggering 218.229 km/h (135.601 mph) – faster than Sheene’s pole lap and the highest race average ever recorded. Sheene’s and William’s bikes were slightly different from the ‘production’ RG500s, with the cylinder dimensions changed from 56mm x 50,5mm to 54mm x 54mm, but otherwise basically identical. In the Belgian GP, Suzuki RG500s filled the top ten placings – the first time a single model had done so in the history of the 500cc Championship.
The Mk1 RG500, with its distinctive un-muffled ‘stinger’ tailpipes, put out a claimed 103 horsepower. The MkII version, produced for 1977 and the 1978 MkIII were similar except for the muffled exhaust system and cosmetic changes to the fairing and seat. The front brakes discs, originally coated aluminium which were prone to breaking when heat cracked the coating, were replaced with stainless steel front rotors and a cast iron rear. For 1979, the engine dimensions were revised to 54 x 54, the same as the factory bikes, with power up to 110 BHP, although still using 34mm Mikuni carbs. Twin shock rear suspension was retained. This specification continued until the 1982 MkVII, which went to magnesium ‘stepped’ crankcases (with the front pair of cylinders lower than the rear) with 36mm carbs and a mono-shock frame. Power was up to 115 BHP. The final RG500 built as a complete bike by Suzuki was the 1984 MkIX, with 38mm Mikunis and a 16-inch front wheel. For 1985, 1986 and 1987, Suzuki built complete power-valve engines only, producing 120 BHP, which were sold with exhaust pipes around the world and fitted into various frames.
During the twelve years of RG500 production, the Suzukis won many major events, including World Championship Grands Prix and Isle of Man TTs, as well as countless national level races. In works ‘XR’ form, the RG took four 500cc World Championships; for Barry Sheene in 1976/77, Marco Lucchinelli (1981) and Franco Uncini (1982). More importantly, the model formed the nucleus of the Senior-class grids across the world, providing privateers with a reliable and competitive means by which to go racing. Today, the RG500 is a very collectible motorcycle.
A survivor
Back in 1984, Ray Moody, owner of Western Motorcycles in Penrith, on the western outskirts of Sydney, had been keeping an eye on a classified ad that had been appearing in Australian Motor Cycle News for several months. For sale was a Mk1 Suzuki RG500, with substantially intact factory spares kit, asking price $4,500. “I watched this ad for months and it looked like there were no takers,” recalls Ray. “Around this time interest was waning in the 500 GP class and Superbikes were taking over. I decided that if it was still for sale in the next issue of AMCN I would go to Melbourne and buy it. I drove down with $4,000 cash and made the owner, Steve Jenkins, a take-it-or-leave it offer, and he took it. So I went back to Sydney with RG500 engine and frame number 11045.”
“It turned out to be the RG500 bought new from Melbourne Motorcycle Company in June 1976 by Mick Hone, who had been racing a TR500 twin Suzuki. Mick’s first ride on the RG500 was in the Australian GP series round at Sandown Park in July 1976 where he finished 3rd in the 5oocc Championship race behind the RG500s of John Woodley and John Warrian. Speaking to Mick later he said that he never really got on with the RG500, fell off it once or twice, and preferred to ride the twin. So he put the RG500 up for sale after the Easter 1977 Bathurst meeting, and it was bought by Steve Jenkins in May 1977, who only rode it a few times before he had a serious accident and broke his back which finished his racing. The bike lay around for five or six years until he decided to offer it for sale.
“In all the time I have owned it, nearly 40 years, I have never started it or done anything to the engine. I had the tank and fairing repainted not long ago with Mick’s number 1 on it. Mick told me that when he bought the bike it came with cast iron front discs and the distinctive ‘stinger’ tail pipes with no mufflers. However before he raced it, Suzuki supplied F.O.C. a set of stainless steel front discs (which are still on the bike), a modified steering stem assembly, and a set of small mufflers which were welded onto the original pipes. I am glad the bike stayed in its original condition because a lot of the early RGs were modified with later parts to keep them competitive. Also, many of the RG500s that came to Australia were bought up by European riders and sent out of the country because there was an enormous demand for them overseas and very few supplied to Europe directly from the factory.”
The original spares kit contains new cranks, barrels, rear sprockets and other parts. There is also the original factory RG500 Owner’s Manual with notations from the previous owners as well as this interesting foreword, “This Suzuki RG500 racer now in your hand is a commercially produced version of the Works Machine RG500, and is built as an accomplished road racer toughened by fierce competition and proven in many wild heats on the racing course.”
With his son and daughter now running the thriving dealership that Ray started almost half a century ago in nearby St. Mary’s, Ray has a bit more time on his hands and plans to spruce up the RG500 and display it in the main showroom which houses new Honda, Suzuki, Can-am and Royal Enfield motorcycles. He has also collected plenty of other ex-racing projects that he plans to tackle, including a Kawasaki A1R and a Yamaha TR3, amongst several others.
Specifications: 1976 Mk1 Suzuki RG500
Engine: Water-cooled square four two stroke with four crankshafts coupled to a single take-off gear.
Bore x stroke: 56mm x 50.5mm
Capacity: 498cc
Compression ratio: 7.7:1
Power: 103 BHP at 11,000 rpm
Torque: 67.2 Nm at 10,500 rpm
Gearbox: 6 speed with chain final drive
Clutch: Dry multiplate
Carburation: 4 x 34mm Mikuni VM34SS
Electrics: Suzuki PEI capacitor discharge magneto
Frame: Welded tubular steel double cradle
Front suspension: Oil-damped telescopic front fork with 35mm tubes.
Rear suspension: Square section swinging arm, gas/oil damper units with five spring preload adjustments.
Wheelbase: 1390mm
Dry weight: 143kg
Fuel capacity: 31.5 litres
Tyres: Front: 3.25 x 18 • Rear: 3.50/5.25 x 18
