On the move: AMA superbike replicas

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On the move: AMA superbike replicas

On the move: AMA superbike replicas

Honda CB 1124 F, Kawasaki Z 1075 S, Suzuki GS 1000 S.

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Legends like Eddie Lawson, Wes Cooley, Freddie Spencer and Wayne Rainey fought their way into the hearts of enthusiastic spectators in the American Superbike Championship at the beginning of the 80s with visually almost standard 1000 series superbikes behind wide handlebars.


Bilski

These classic superbikes stand out from the colorful all sorts of current racing motorcycles like birds of paradise.

Martial, downright angry to look at, brutally strong and hellishly loud, they drifted and wheeled wheel to wheel and handlebar end to handlebar end for American racing courses and fought for every inch of track; US boys on Japanese 1000cc four-cylinders from Honda, Kawasaki and Suzuki. With factory support, three of the four Japanese manufacturers not only created exciting competition, but also their own publicity. The production superbikes dominated the racing scene in the USA, and a win could have a decisive influence on sales. The regulations ensured the visual proximity to the street offshoots.

In order to guarantee the most attractive races possible, the AMA, the American Motorcyclist Association, relaxed the regulations in 1980. The four-cylinder, derived from street motorcycles, were allowed to have a maximum displacement of 1025 cm³. The engine housing, cylinders and cylinder heads had to come from the series, and the carburetors were limited to 31 mm in diameter. The original frame and the swing arm could be stiffened, otherwise engine tuning was allowed, whatever technology and material provided, the exhaust system was free to the manufacturers.

Renowned tuners such as Rob Muzzey and Pops Yoshimura pushed the Kawasaki and Suzuki engines to the limit of what was feasible with the support of the factories – and sometimes even beyond, which was often demonstrated by violent explosions. And when the engines stopped, they often enough shredded the Goodyear slicks on the rear wheel. Amazingly, Honda was not able to convert the advantage of the four-valve technology of the Bol d’Or into a decisive increase in performance compared to the aging two-valve systems of the Kawasaki Z 1000 S and the Suzuki GS 1000 S, which was ultimately reflected in the results: in 1979, Wes Cooley won the 1000cc Suzuki the title.

1980 was perhaps the most exciting, but also the most dramatic year in the series: Honda threw four drivers into the battle for market share with Freddie Spencer, Ron Pierce, Steve McLaughlin and Mike Baldwin. Kawasaki offered two pilots with Dave Aldana and Eddie Lawson, only Suzuki trusted a soloist with Wes Cooley. The first 9 races were clearly dominated by Cooley, Lawson and Spencer and with three wins each in the last race in Daytona they had every chance of winning the championship.

There it came to a scandal: Eddie Lawson had secretly swapped his wounded motorcycle for that of his team partner Dave Aldana after training. Wes Cooley wondered about Aldana’s absence, noticed the rule violation and protested, but the arbitration panel started Lawson: it had forgotten to seal its motorcycle beforehand. During the race, Lawson crashed due to a leak in the oil cooler. After a bitter fight between Cooley and Spencer, the Suzuki had the front wheel at the finish line by the width of a tire. But in the middle of the Suzuki victory celebration, the Kawasaki protest burst. An official declared the Suzuki’s rear frame non-compliant, which brought Freddie Spencer the preliminary win and Eddie Lawson the championship. Months later, the AMA revised its verdict and Wes Cooley was awarded the title.

In 1981 the three-way battle was no less hard: Again the decision was made in the last race in Daytona, in which Eddie Lawson won the title, and this time quite regularly, also in 1982. In 1983 Wayne Rainey continued the Kawasaki series of successes.

Three motorcycles, three philosophies

Honda CB 1124 F..

Today, almost 30 years later, the AMA superbikes are experiencing a renaissance not only in the USA. A scene has also established itself in Germany that builds and restores such motorcycles and thus fights for laurels free of displacement restrictions: The IG Classic Superbikes has launched a series that competes in its championship with such motorcycles in 5 races. There are three superbikes in the paddock at Hockenheim that could have turned off the Daytona piste in the 80s: the blue and silver Bol d’Or with the number 19, as ridden by Freddie Spencer, the bright green Kawasaki, the Eddie Lawson and Wayne Rainey helped to master honors, here in the Rainey specification with starting number 60, and the blue and white Suzuki with the number 34, which was to bring Wes Cooley to fame. By the way: Years later, a certain Kevin Schwantz took over Cooley’s Superbike, which is why he was to make himself and the number 34 immortal from now on.

The three motorcycles interpret the AMA Superbike theme completely differently. Ralf Beginn has undoubtedly chosen the most generous layout for his Bol d’Or. The engine, prepared by the Team d’Or, has been trimmed for performance with a lot of effort, not for absolute peak power, but for high torque in the medium speed range. 1124 cm³ displacement, thanks to Wiseco pistons with a diameter of 72 mm, which compress the mixture 12.5: 1, modern 35 mm flat slide racing carburetors from Keihin, larger valves, the usual processing of combustion chambers and channels as well as an exhaust system with titanium manifolds and a current one cylindrical silencers push the inline four-cylinder into a real power bar.

The series camshafts of the 1100 Bol d’Or are used for a full punch in the middle speed range. The yield is impressive: ample power and torque curves; 142 hp at 8500 rpm on the rear wheel and thus probably more than the original. No less effort goes into the chassis. The fork and swingarm come from a Yamaha FZR 1000, the R1 brake calipers grapple with braking discs. The 17-inch cast wheels from OZ are fitted with modern, 120 and 180 mm wide super sports tires. The swing arm is supported by a Wilbers central spring strut on the modified frame. Thanks to the authentic decor, however, the massive interventions are only noticeable at second glance. With a full tank of 226 kilograms, Ralf Beginns Honda has lost 34 kilograms compared to the series Bol d’Or.

Even at a third glance, Klaus Dony’s Kawasaki Z 1000 S, owner of Bike Side, did not reveal any serious deviations from Wayne Rainey’s racer – which took a lot of work. The family genes are not only visually closely related to the Urwerk, but also technically: the brake disc adapter, the grooved discs and the special brake calipers from an American manufacturer, the 18-inch Dymag wheels made of magnesium and the elaborate aluminum swingarm with the integrated Engine ventilation tank, all of this shows love and meticulous attention to detail. Even the shock absorber struts helped Eddie Lawson and Wayne Rainey to master honors.

Of course, the engine is also perfectly prepared: authentic Keihin CR racing carburetors, sharp WebCam camshafts, higher compression Wiseco pistons, good for 1075 cm³, the entire tuning program with larger valves and processed channels, double ignition and the typical, megaphone-shaped dungeon exhaust system . So the power output should be close to that of the 1979 engine, which upgraded the Kawasaki factory kit at the time. 130 horses should have easy play with 198 kg.

Thomas has exactly the opposite philosophy "Tommy" Hofmann from the Bochum motorcycle smithy on one of his two superbikes. The Suzuki GS 1000 S also looks very authentic and seems to have fought one or the other battle. In fact, a sticker on the tank indicates that she was already racing in Colmar-Berg in 1982. By his own admission, it’s Tommy’s low-budget bike. Thomas Hofmann bought it very cheaply and carefully modified it. Tommy combined the fork of the first Suzuki GSX-R 750 and its 18-inch wheels with the original swing arm, which is based on the historical model and reinforced with beams. The front brake system comes from a GSX 1100 EF.

The owner has left the engine in the original, only Keihin CR carburettors, a Vance & Hines 4-in-1 system and the electronic ignition system of a katana are supposed to make the engine work and release almost 100 hp. At 194 kilograms, the Suzuki is astonishingly light thanks to filigree relief measures such as the perforated engine side cover. It undercuts the production version by a full 61 kilograms, i.e. almost a quarter, and thus partially compensates for the lack of performance compared to the competition.

Driving impression Honda CB 1124 F and Kawasaki Z 1075 S

Kawasaki Z 1075 S..

Different philosophies and requirements create plenty of tension; Even in the pits, the classics attracted the curious glances of numerous visitors: martial, sweeping handlebars, large square start numbers and the technology are openly on display, so to speak, bike nudists in the paddock. With rhythmic bursts of gas, the four-cylinder in-line warm up and roll one after the other out of the pit lane onto the big Hockenheim circuit.

In contrast to most classic racing motorcycles, the sitting position behind the wide handlebars – the upper body only slightly bent forward, the legs angled in a sporty way – is unusual at first, but not uncomfortable. This impression is supported by the performance of the Honda: From 4000 rpm the engine pulls through with brute force and happily revs up to 8000 rpm. Above that, the turning pleasure decreases noticeably. The four-cylinder inhales sonorous, muffled and clears its exhaust gas in a clearly audible manner, but by no means in an infernally loud manner through the 4-in-1 and sounds similar to a current 1000cc four-cylinder with a retrofit system.

With tremendous thrust in the middle speed range, the Bol d’Or has an almost touristy character. As it will turn out later, it can be downright lazy to change gear compared to the competition and can easily go up a gear in angled passages like the Motodrom. This characteristic brings enormous advantages from tight corners, such as the hairpin after the Parabolika and the Sachskurve, especially since the gear ratio is chosen to be relatively short. In the Parabolika this is reversed to the disadvantage, because long before the braking point, the tachometer needle is in the red area, which corresponds to about 245 km / h and forces the driver to take the gas off.

The chassis processes bumps cleanly, but the rear end becomes restless when braking hard. Thanks to its modern braking system with one-piece four-piston fixed calipers, the potent Bol d’Or brakes almost like a modern sports motorcycle. Its weight cannot be denied, and neither are the wide 17-inch tires that make a lot of demands on the chassis. Despite the wide handlebars, it requires strength when turning and lacks the last bit of steering precision. Freddie Spencer would probably have been amazed at the performance characteristics and the brakes, but would have preferred the handling and maneuverability of his duty bike.

Then it is the Kawasaki’s turn. The seating position behind the somewhat narrower handlebars immediately appeals; A feeling of well-being sets in. No sooner have the round slides opened than a broad grin spreads across the driver’s face. Although there is not much movement below 5000 rpm, the Kawasaki four-wheeler gets going like a real racing engine and turns vehemently from 7000 rpm to almost five-digit regions. Exactly as Eddie Lawson put it: "Things come in with a kick in the ass from 7000 to 10000 rpm."

The Dony-Kawasaki also knows that kick in the buttocks. Fascinating side effect: In the lower speed range, the dungeon system emits a dull roar, which with increasing speed replaces a pressed, infernal howl. With this sound, she distances herself completely from modern motorcycles with 4-in-1 systems; The driver listens ecstatically to the unique experience and looks forward to every double-break. Even in the last gear in the Parabolika, he enjoys the continuously changing pitch. Although the Kawasaki is no quiet step, the fan does not consume hard rock in the quiet, after all. In the pit lane you can already hear when the Kawasaki turns into the Motodrom, and more than one visitor later tells of goose bumps and showers that run down your spine when the Kawasaki howls past 5 meters on the start / finish straight.

The bright green superbike has other surprises in store. Extremely handy, at the same time precise and stable, it circles both slow and fast corners. The next surprise when braking: The system can be precisely metered and requires little manual force, which encourages the driver to shift the braking point further and further back. The stoppers can definitely keep up with modern systems. After a few laps, the driver has zeroed in on the green and feels completely comfortable; Power, chassis, brakes and sound form a homogeneous unit. Tuner Rob Muzzey, who developed the Kawasaki into the AMA’s best superbike in the 1980s, would probably compliment the motorcycle; Eddie Lawson and Wayne Rainey would recognize their master bike.

Driving impression Suzuki GS 1000 S

Suzuki GS 1000 S..

The tester climbs onto the Suzuki, still full of euphoria. But even at the start, the clutch requires a lot of manual effort, as does the throttle. To guarantee that the four throttle valves close securely, owner Tommy has installed a relatively strong return spring. On the Kawasaki, which also relies on the Keihin CR carburetor, an opener and a closer cable solve this problem more elegantly. Once the throttle slide is fully open, the engine turns evenly towards the red area without noticeable drops, but also without major power eruptions. Here goes the sound of the Vance & Hines-plant from dull rumbling gradually into bright singing.

When braking from high speed in front of the hairpin, the next show of strength is on. Only the highest effort from the right forearm delays the Suzuki adequately. Downshifting the stiff transmission, clutching, double-declutching, almost every function
challenges the muscles, even turning in. In tight corners, the Suzuki is unwilling and again demands effort, this time on the handlebars. Most astonishing, since the lightest motorcycle of the trio with its narrow 18-inch tires actually offers good conditions. Obviously, the chassis geometry is designed for stability: In the series version, the 1000 series Suzuki had the longest caster with an almost identical wheelbase: 116 millimeters; the Kawasaki Z 1000 S got by with just 90 mm. Accordingly, the Suzuki masters the discipline of driving stability properly. It can easily cope with bumps in a sloping position, even at high speed.

After the 20-minute turn, the tester slowly ran out of stamina, he felt the tennis elbow syndrome on both sides and caught himself rolling through the Motodrom in a higher gear while saving gear changes. But only the Honda calmly accepts that without losing much time. Owner Tommy, who uses the Suzuki in classic racing – eight turns of 20 minutes each in Spa couldn’t harm him – does not know these problems. When the Suzuki pits again, his mild smile signals unmistakably: The Suzuki is a motorcycle for men. Of course, Pops Yoshimura elicited far more power from her at the time and sent the most powerful motorcycle into the field by 1980, but also used a multiple of Tommy’s budget for it. After all, he has a considerably more potent Suzuki with a GSX four-valve engine in the stable, which has been prepared with far greater effort. Wes Cooley would certainly have preferred to go back to the original, not just because of the far higher performance.

A hot day with many laps and even more impressions comes to an end not only because of the midsummer temperatures. Three motorcycles, which at first glance show strong relationships, turn out to be completely different characters, each with a very specific charm and a high fun factor. The Honda, which with its beefy performance characteristics would also be suitable for the leisurely Sunday trip with pillion, the Kawasaki, which conveys pure AMA Superbike feeling in every respect, and the Suzuki, which always and always challenges the whole man.

Motorcycles that laid the foundation for higher tasks 30 years ago. The tough AMA Superbike school developed in the late 1970s to the 1980s into the cradle of the greats who formed world champions from talented local heroes. American drivers have never before or since dominated the 500cc World Championship as they did at this time and gave birth from 1978 to 1992 "King Kenny", "Almost Freddie", "Steady Eddie", Wayne Rainey and "Revin ’Kevin" world championship fame and more than a dozen titles in the premier class.

Technical specifications

Honda CB 1124 F.

Engine: Air-cooled four-cylinder four-stroke in-line engine, two overhead camshafts, four valves each, bore x stroke 72 x 69 mm, displacement 1124 cm³, 142 hp
8500 rpm

Power transmission: Multi-disc oil bath clutch, five-speed gearbox, chain

Landing gear: Double loop frame made of tubular steel, telescopic fork, two-arm swing arm made of aluminum,
Central spring strut, tires front 120/70 ZR 17, rear 180/55 ZR 17

Weight: 226 kg with a full tank

Kawasaki Z 1075 S.

Engine: Air-cooled four-cylinder four-stroke in-line engine, two overhead cams-
shafts, two valves each, bore x stroke 72 x 66 mm, displacement 1075 cm³, 130 hp at 10000 / min

Power transmission: Multi-disc oil bath clutch, five-speed gearbox, chain

Landing gear: Double loop frame made of tubular steel, telescopic fork, two-arm swing arm made of aluminum tubes, two spring struts, tires 110/80 ZR 18 at the front, 150/70 ZR 18 at the rear

Weight: 198 kg with a full tank

Suzuki GS 1000 S.

Engine: Air-cooled four-cylinder four-stroke in-line engine, two overhead camshafts, two valves each, bore x stroke 70 x 64.8 mm, displacement 998 cm³, 100 hp at 9200 / min

Power transmission: Multi-disc oil bath clutch, five-speed gearbox, chain

Landing gear: Double loop frame made of tubular steel, telescopic fork, two-arm swing arm made of tubular steel, two spring struts, tires in front 110/80 ZR 18, rear 150/70 ZR 18

Weight: 194 kg with a full tank

IG Classic Superbikes

How did the American Champs compete with superbikes on the racetrack? It can be done. The IG Classic Superbikes has launched a racing series in which the Japanese multi-cylinders are used. The regulations are relatively simple: In the AMA Legends and Vintage classes, air-cooled four- and six-cylinder engines are permitted, and charging and injection are prohibited. A one-piece handlebar mounted on the fork bridge is required. In the no-limits class, on the other hand, the game rules without limits. Only the frame and tank must belong together and come from a model built up to 1983. Different wheels and tires are approved in the three classes, the displacement is free. Information: www.classicsuperbikes.de

On the move: AMA superbike replicas

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