Sport: Suzuki GSX-R 750 – the most dominant series motorcycle

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Sport: Suzuki GSX-R 750 - the most dominant series motorcycle
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Sport: Suzuki GSX-R 750

The most dominant production motorcycle in racing

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At the end of his frenzied professional life, Mick Grant did pioneering work for near-series racing: The brand new Suzuki GSX-R 750 with its traditional starting number won the first British Superstock title in 1985.

Probably no other production motorcycle has entered the sport as dominantly as the GSX-R, and nothing proves this statement better than its superiority at the premiere of the British Superstock Championship: Suzuki drivers won nine out of eleven races, the first four went in one go to the Grand Prix warrior Mick Grant on his machine built by Heron Suzuki, the UK importer. Over the course of the season, the 41-year-old continued to collect points, won the series with five victories – and then retired.

GJust three Japanese manufacturers support the Superstock series, the secret of which was similar to that of the Superbike category in the USA: the racers are technically and largely optically close to their series counterparts. No wonder, because the British Bruce Cox launched the US series in 1973, and when he returned home, he imported the successful idea. "However, I wanted to exclude the extremely expensive engine tuning that would benefit the works teams. The engine and carburetor therefore had to remain as standard. Racing tires, different suspension, brakes, swing arms and wheels should nevertheless make real racers possible."

Even so, the importers naturally had certain advantages. For example, they got new models earlier than the privateers. While the GSX-R were still in containers for private customers, Heron mechanics Paul Bolton and Nigel Everett were able to lend a hand long before the Superstock debut. "Of course, we were haunted by the company information of 100 hp", reports Bolton, "and so we were amazed when we could only measure 73 at the gearbox output. We completely rebuilt the engine and optimized it within the rules. A titanium exhaust system from the factory TT1 racer came on, the air filter disappeared. Instead of the 97.5 main jet, we turned a 130 into the series carburettor, deburred the combustion chambers and ducts, increased the compression to 10.7 instead of 9.8: 1, removed the alternator, installed a tiny battery – and reaped real 96 hp at 10,500 rpm. That was a little better."


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Only the tachometer and power switch remained in the boned cockpit.

Mick Grant picks up the narrative: "I had only driven Suzuki since 1982 and loved my RG 500 as well as my four-stroke bike for the TT Formula 1. But in 1985 Denys Rohan, the Heron boss, wanted to promote the new GSX-R by showing me in the new Superstock- Class at the start. I didn’t like that at all, because I vividly imagined crowds of crazy people trying to chase old Mick Grant on machines that were ready to go for £ 5,000. In the end, against my conviction, I agreed, won the first four races – and the whole thing seemed like a great idea. The Suzi was nice to drive and as reliable as a Swiss watch. I also won the Production TT with it, ahead of three other GSX-Rs. My only fall with the Superstocker happened during pre-season training in Donington, and I remember cursing myself for twisting around with such a ‘serial bitch’ on departure. It then turned out that Suzuki had chosen the thread of the oil filter a little roughly and that it had loosened."

Mick’s success fueled rumors that the Heron-Suzuki did not correspond to the series. So he had the bike opened completely in front of the competition. "It was original, except for the ignition box, and that was allowed. We were able to turn 500 revolutions higher before the limiter was activated, saving us a lot of gear changes." In his last race in Great Britain, Mick clinched the Superstock title with seventh place, and shortly afterwards he ended his career as the winner of the Macau Grand Prix on the RG 500. A year later, Heron gave him a very personal restoration from the successful superstocker and mechanic Nigel Everett: The GSX-R with the frame number GR71-00719 and the engine R705.104962 has – since its Donington crash – a scratch on the tank and a dent in the tank frame.

I meet this story on wheels at the TT Revival in Killarney / South Africa, where Mick is one of the regulars. Suzi has belonged to ex-racer Tony Salt for three years, but the two of them got a good deal: "I can drive the machine whenever I feel like it", Mick grins and passes the good piece on to me. My historical excursion is completed when Paul Bolton turns up, now responsible for the restoration of historical Suzuki racing motorcycles. It patiently warms up the engine – an absolute must for the air / oil-cooled wet sump engine with more than five liters of oil. During the race, the oil temperature was 100 to 110 degrees Celsius, and test bench runs had shown Heron that the performance even increased at higher temperatures.


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Mick Grant hands over the glorious Superstock Suzuki to Alan Cathcart.

After getting on, a real surprise awaits me: I forgot how low the seat of this superbike is. Not only in comparison with later competitors, but also with contemporary FZ 750 or VF 750. At the same time, I am amazed at the curved seating position and the almost plush bench. You sit as if wedged on this bike, have trouble hanging off and remember Mick’s economical and old-fashioned riding style. So the hottest tip for fast laps is: Trust the grip of the mounted Michelin Pilot One and boldly throw the bike into the corners. Tony Salt mounted the 17-inch wheels of a current GSX-R in order to be able to mount the modern tires. Neither the standard 18-inch wheels nor the 16-inch wheels Grant rode at the time would have made this possible.

16 incher? Well, Mick found the standard caster too big. He also wanted to use the same tires as his other racing machines. The Superstock regulations made it possible to fit the entire front end of an older TT1 Suzi, which, with its Kayaba fork, hydraulic anti-dive, 310 mm Brembo discs and four-piston Tokico brake calipers, was essentially the front of the GP motorcycle at the time from Randy Mamola resembled. The new owner has also retrofitted the gearshift: once you’ve learned to race on a Velocette, you’ll insist on shifting up gear for the rest of your life. Normal people – sorry, Mick – don’t need that.

The optimistic factory specification in 1985 spoke of 176 kg dry weight. Anyone who dismantled double headlights, speedometers, indicators, taillights, starters and alternators for racing resulted in a real 159 including oil, but without petrol. And that feels good. At first glance, the standard flat slide carburettors appear less responsive. They use a significantly reinforced gas slide spring to counteract the suction in the intake tract and prevent the slide from occasionally jamming. Until the Michelin have reached their operating temperature, the spontaneously acting Mikunis make it easier to control rear wheel slides. Nevertheless, you first have to learn to adjust them to every curve, and their hard response naturally makes double-declutching difficult when downshifting and braking at the same time.

When I rush to the first left turn, Suzi surprises me again: Her brake is on strike. To be fair, Tony Salt warned me against it, so I’m ready to pull the lever with all my might. The effect remains moderate. So I bring it up to operating temperature by letting it slide for a lap with light lever pressure. After that, she works well enough to safely catch me at the end of the 800 meter back straight. However, it remains wooden, and I remember this problem arose when Brembo switched its discs from cast iron to stainless steel.


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Out of the box and onto the slopes: in 1985 none offered better conditions for series-based sports than the lightweight GSX-R.

The Superstock engine operates at 2500 rpm idling speed – a Suzuki trick from times before the introduction of the slipper clutch. It was supposed to prevent the engine’s braking effect from provoking unrest in the chassis. So I don’t have to worry too much about the rear wheel when I drop anchor in front of the Killarney hairpin: zack, zack, down into second gear; the first is only suitable for starting up with the GSX-R. Overall, the pleasant Superstock engine is still nice to drive, comes out neatly thanks to the TT1 exhaust system, has a decent midrange power.

Nevertheless, the changes to the carburettors and exhaust ensure that the racing performance only starts at 5000 rpm, at 7000 the kick comes, at 10 500 the standard limiter intervenes – overall a very narrow usable speed range for a 750 cc racing engine . As mentioned, Mick Grant had 500 more tours available. Thanks to the well-stepped right-hand six-speed gearbox, the engine always stays in a good mood, even if I sometimes find it difficult to upshift without the clutch.

In 1985 the Suzuki had to put up with some criticism of its driving behavior, and Mick reports that his super stooler sometimes unsettled him with a slight high-speed commuting. From my point of view, the GSX-R was just different from what I was used to up to now: not nervous, as many contemporaries thought, but simply no longer a stubborn iron pile. Of course she reacted palpably and very sensitively to setup changes, and so I’m probably a little lucky when she steadfastly bolted down the two straights of Killarney. In long and tight bends, however, it convinces – always with the Superstock chassis and almost by today’s standards – with its precision, neutrality and lightness. Your tendency to understeer can be compensated for with little effort, the responsive suspension makes handling on the bumpy course much easier.

I still do a few more laps with great satisfaction and think again that it is wrong to call Honda’s Fireblade the first modern sports motorcycle. No, folks, eight years ago Suzuki paired the performance of a 1000 with the handling of a 600. It was no longer evolution, but revolution. That was GSX-R.

Technical specifications


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The standard carburetors of the Suzuki GSX-R 750 received larger nozzles and stronger springs.

engine design type  Air / oil-cooled four-cylinder four-stroke in-line engine, four valves per cylinder, two overhead, chain-driven camshafts
drilling  70 mm
Hub  48.7 mm
Displacement  750 cm3
compression  10.7: 1
power  97 hp at 10,500 rpm
Mixture preparation  Flat slide carburetor Mikuni, Ø 29 mm
 
Power transmission
coupling  Multi-disc oil bath
transmission  Six-speed, claw shift
Primary drive  Gears
Secondary drive  Chain
 
landing gear
Frame type  Double loop frame made of aluminum profiles and cast parts
Front wheel guide  Kayaba telescopic fork, Ø 40 mm, hydraulic anti-dive
Rear wheel guide  Two-sided swing arm made of aluminum profiles, WP central spring strut
bikes  Cast wheels
Front / rear tires  120/70 – 17/180/55 – 17
Front brake  Brembo double disc, Ø 310 mm, four-piston fixed callipers
rear brake  Single disc, Ø 220, two-piston fixed caliper
  mass and weight wheelbase  1440 mm
Weight  159 kg
 
Manufacturer  Heron Suzuki, Crawley, England

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