Who better than future 500cc World Champion Kevin Schwantz to demonstrate the capabilities
In the beginning there were sportbikes, and they were fast. Reagan-era sportbikes were also huge, ill-handling and, when pushed hard, just as likely to launch you skyward as rocket you forward. These mutant UJMs were crude appliances, producing great power but offering little control. Harnessing that power required major surgery: bracing the frame and replacing the suspension, wheels and braking systems wholesale. Wes Cooley’s #34 AMA Superbike had about as much in common with a Suzuki GS1000 as Travis Pastrana’s #99 NASCAR racer does with the Toyota you rented the last time you traveled.
Then Suzuki unleashed the 1985 GSX-R750, and everything we knew about sportbikes changed forever. Here was a production motorcycle that was virtually race-ready right off the showroom floor—the proverbial “racebike with lights.” Rather than follow the traditional design model and modify a streetbike for better on-track performance, GSX-R Lead Engineer Hiroshi Fujiwara flipped the program and took a highly specialized factory racing machine—Suzuki’s world championship-winning XR41 endurance racer (see sidebar, page 64)—and made the minimum modifications necessary for street use. “We had no competitors in the market,” Fujiwara said. “Our competition was factory racing machines.” Built with bona fide racing technology, the radical GSX-R750 was the first genuine racer replica, and the archetypal modern sportbike.
The original design brief was blunt: Build the fastest motorcycle in the world. But it wasn’t outright power Suzuki sought; it already had the sledgehammer-like GS1150E for that. GSX-R Project Leader Etsuo Yokouchi identified three distinct performance targets for the new machine: the highest top speed, the quickest acceleration and the lowest circuit lap time. The GSX-R750 would be comprehensively fast, and it would employ every trick Suzuki knew from racing: aero-dynamic bodywork, a compact, high-revving and powerful engine, and a light, stiff frame.
“Born on the Circuit” was Suzuki’s tagline for the
original GSX-R, and it wasn’t empty rhe
The all-new GSX-R had nothing in common with its pedestrian GS predecessors. Clip-on handlebars, rearset footpegs, foam-backed gauges and an externally vented fuel tank came directly from the race paddock. The trick, cast-and-extruded aluminum cradle frame—the first example of that technology on a modern production bike—was lifted from the XR41 endurance racer, along with the Full Floater monoshock rear suspension and sophisticated Positive Damping Fork. The full-coverage fairing concealed a massive oil cooler in its maw, hinting at the power within. Even the wheel size was race-inspired. Suzuki led the shift to quick-steering 16-inch front wheels on previous production bikes, but the GSX-R used 18-inch hoops, just like the factory endurance racers, to facilitate quicker brake and tire changes.
Motorcyclist staffer Jeff Karr’s report from the world press launch at Suzuki’s private Ryuyo test track in Hamamatsu, Japan, might seem hyperbolic in retrospect if it wasn’t spot-on. “This new Suzuki is not just an artful rehash of current streetbike technology, but a true milestone,” Karr crowed in our April ’85 issue. “Here is new technology that until now has been deemed too costly to apply to a streetbike. Here too are new ideas never before seen on any motorcycle. This Suzuki might turn out to be a new standard in overall performance.”
Many new ideas could be found inside the GSX-R’s unique, oil-cooled engine. Suzuki’s XN85 Turbo employed a cruder form of oil cooling two years earlier, but Engine Development Leader Yosunobo Fujii took that technology one step further and designed an innovative system using two separate oil pumps—one to lubricate the engine and another to route oil through a large cooler beneath the steering head and draw off excess heat. The oil-cooled engine made more power than an air-cooled equivalent, without adding as much weight as liquid cooling. Without water jackets surrounding each cylinder the engine was narrower and more compact, too.