It’s hard to think of any new model as immediately dominant straight out of the box as the Suzuki GSX-R750 was in its debut 1985 season. Nothing demonstrated this better than its supremacy in that year’s inaugural MCN Superstock British Championship—the first ever series run anywhere in the world to carry the Superstock name—where the new GSX-R750 dominated, winning nine of the 11 races. Veteran star Mick Grant, then 41, won the first four rounds in succession. Grant would go on to convincingly wrap up the title with five victories in the end on the bike entered by UK importers Heron Suzuki, and sponsored by adult magazine Men Only. Each of the races in the series offered nail-bitingly close racing between topline riders on evenly-matched machinery that the average spectator could readily identify with–the whole rationale of the Superstock category, and today’s Superbikes. Dipping in and out of each other’s slipstreams, sitting it out three abreast under braking for chicanes or hairpins, swapping the lead half a dozen times a lap, these Super-headbangers of all generations on their Superstockers revitalized a UK racing scene that was then flagging because of the economic downturn. Sound familiar?
The key ingredient of a series enthusiastically supported by three out of the four Japanese manufacturers, was that it pitched sporting streetbikes like those lined up in the circuit bike parks against each other with a minimum of tuning. As such, it represented the British counterpart of the AMA Superbike category, which was christened as such by the man who invented the streetbike-derived class in the USA in 1973, British expat Bruce Cox. He’d returned home to the UK in 1982 to run the no-holds Yamaha RD350LC ProAm series, then dreamt up and promoted the Superstock category.
“I wanted to bring our Superbike concept to Britain, but without the expense of tuning the engine, which by then had started to fragment the AMA field between the importer-backed teams and the true privateers,” says Cox. “The bikes needed to be proper racers, which is why we let them run slick tires and gave complete freedom for brakes and suspension, including the swingarm. But it was important we retained the silhouette of the stock model, so they had to run standard bodywork and you weren’t allowed to alter the main frame loop—no cut ‘n’ shut on the steering head, for example. However, the most important thing was the engine had to be 100-percent stock, and that included the carbs—we caught Yamaha machining theirs and turning them into smoothbores, for example, which meant Steve Parrish got kicked out of the results at Snetterton! The result was that impecunious privateers like Trevor Nation or Terry Rymer, whose dad prepared the bike in the garage behind their home, could compete with the better funded importer entries, and win races. That’s why I called it Superstock—Superbike chassis mods, but stock engines. It seems like the name caught on—as well as the concept!”
Indeed so.
However, there was still one way that an importer team had an edge over its customer rivals, and that was when it came to getting hold of any new model in time to do meaningful development on it before the start of the season. Easter came early in 1985, with the MCN Superstock series kicking off on April 5 at the Brands Hatch Good Friday meeting as a support class to the Transatlantic Trophy USA/UK series, which Cox also promoted. But the first GSX-R750 shipment from Japan had barely docked, meaning that even if they were lucky enough to get hold of a bike, customer teams had no time to do much more than stick race numbers on a stocker, whereas the Heron Suzuki team had taken the precaution of flying the first of the new bikes straight from Japan to the UK early in the New Year, giving plenty of time for mechanics Paul Boulton and Nigel Everett to prep it up, and Mick Grant to go testing on the first production GSX-R750 in Europe at Donington Park, before the start of the season.
Time was vital in making the new Suzuki Superstocker at all competitive, let alone a winner, recalls Paul Boulton. “We’d read all the factory literature quoting 100 bhp, so when we got just 73 bhp at the gearbox after running it in, you can imagine the reaction!” he says. “So we double-checked it on another dyno—same reading. However, blueprinting the engine and progressively modifying it within the rules brought it up to scratch—we fitted a factory titanium race exhaust off the TT1 bikes, removed the airbox, increased main jet sizes from 97.5 to 130 on the stock carbs, cleaned up the cylinder head, raised compression from the stock 9.8:1 to 10.7:1, removed the generator and ran a total loss battery—and got a genuine 96 bhp at 10,500 rpm, which was a bit better!”
Mick Grant takes up the story. “I’d been riding full time for Suzuki since 1982, and I really enjoyed racing the RG500 two-stroke GP bike, with the TT Formula 1 as my four-stroke ride. But for 1985, Denys Rohan [then the boss of Heron Suzuki – AC] wanted to promote the new GSX-R750 by getting me to ride it in this new Superstock class, which I absolutely did not want to do. I could see that with stock motors there’d be lots of young nutters out there trying to make a name for themselves by beating Mick Grant with a bike they could put on the grid for 8,000 dollars. Well, in the end we did a deal, and I agreed to do the series against my better judgment. But then we got the bike early, set it up, and I won the first four races on the trot with it, after which it all seemed a bloody good idea! It was a lovely thing to ride, and extremely reliable, built like a Swiss watch – I also won the Isle of Man Production TT on a box-stock version ahead of three other Suzukis, and it was rock solid everywhere and rode bumps well. The only time I fell off the Superstocker was after just four laps in the pre-season Donington practice, and I remember thinking as it flicked me in the air, ‘what am I doing riding this piece of crap?!’ It turned out Suzuki had used too coarse a thread on the oil filter, which had come unscrewed; we had to wrap a jubilee clip around it to stop that happening. The first batch of customer streetbikes all over the world had to be rectified like that until they produced new cases with a finer thread to stop that happening.”
To read more on the 1985 GSX-R 750 revisited in this week’s Cycle News, click here
For more Cycle News Sport Bike motorcycle reviews, click HERE.
For more Suzuki motorcycle reviews, click HERE.
