There is horsepower, and there is handling. Beginning in 1969, the Japanese were quickly winning the horsepower wars, but the Europeans had a far better understanding of handling. The Japanese could win races, but a chassis suitable for a racetrack is vastly different from one that needs to be used for doddering around town and then careening through the curvy countryside. Or even going to the local track for a day of dicing with your friends.
The late 1970s was the time of expansion for Japanese motorcycles—expanding engines, that is. As did Suzuki, whose marketing types apparently saw the probability of 1,000cc production racing, be it at club level or professional—and the AMA initiated the Superbike class in 1977.
Suzuki, having made an expensive mistake with the rotary-powered RE-5 in 1975, decided to go along with the UJM in-line fours. First was the excellent GS750 of 1977 (Retrospective, March 1995), but big was the rage, and that meant displacing a thousand or so cubic centimeters. However, “big” also meant serious stress problems—and we don’t mean the kind of stress a rider might feel diving into a corner at dangerous speed. No, the stress we’re interested in is that of an engine spinning thousands of revolutions per minute while trying to free itself of the frame.
Suzuki took that to heart with the GS1000, introduced in late 1977 at the company test track in Japan. A UJM on a racetrack? The company will be embarrassed, thought many journalists. Not a chance. It was an outstanding intro, with engineer Hisashi Morikawa on hand to be applauded for his work. He had also been responsible for the exemplary GS750, so in effect was a practiced hand. But with the sporting world looking eagerly toward the liter bikes, he understood well that more strength would be needed in the chassis.
The essential frame was a twin cradle, with five tubes sprouting from the steering head, two going down and underneath the engine, the other three angling back under the gas tank. The steering head itself was properly reinforced, since this is where many handling problems originate, and one tube angled rearward and downward to meet up halfway with the parallel tubes running back to the swingarm pivot point…another sensitive spot. These top tubes were cross-braced no less than five times as they came back toward the seat. This was all thin-wall tubular steel construction, and the frame was quite capable of withstanding any and all stresses, from braking to cornering on a bumpy road. And the weight, surprisingly, was a mere 38 pounds!
At either end were those mysterious devices called suspension units, into which Morikawa put a lot of thought. These contraptions used springs, oil and air in an effort to keep the wheels on the ground and the rider in control, and were made by an outfit called Kayaba—still very much in business.
Up front the long 38mm fork, running a little over 30 inches in length, used dual-rate springs, and the company kindly provided an air-pressure gauge and a little pump in the toolkit to allow the rider to adjust for individual preferences. Unfortunately the two legs did not have a crossover tube, so each side had to be done separately. However, later in life somebody did add a connector on this model—makes the job much easier, and done in half the time. The steering head used tapered roller bearings to ensure smooth action, and the rake was 28 degrees, trail, 4.4 inches.
At the back the twin shocks had five settings for spring preload, a type of adjustability that had been around for many years. But the rider could also adjust the damping by turning a wheel-type device and changing the size of the orifices to determine damping rates. Take note: this was brand new stuff for 1978, and lots of well-meaning riders managed to screw things up completely by mal-adjusting things. Correctly set, this GS1000 handled better than any other Japanese liter-bike.
Not that Morikawa was going to forget the engine. He chose, in effect, to improve the basic concept of the eight-valve 750 motor. The 65mm bore was increased to 70mm, the stroke lengthened to 64.8mm, for a total of 997cc. Cutting down on rotational mass was a key element, and the crankshaft now used “pork-chop” counterweights, rather than the full-circle type of the 750. This cut down the weight by more than two pounds. Tossing the kickstarter and all its components, and actually being able to shorten the crank and make the 1000’s engine slightly narrower than the 750’s saved more weight. No mean feat. Compression ratio was increased from 8.7 to 9.2:1, with rear-wheel horsepower going from the 750’s roughly 55 to 75.
Wheels were spoked, 19 inches on the front with a single disc brake, 18 inches at the back, again with disc brake. Wheelbase was a moderately lengthy 59.3 inches. A slightly sexier GS1000E, with mag-type wheels and a second disc up front, soon came along. Price for the basic GS1000 was a reasonable $2,750, up against Kawasaki’s $2,900 for a KZ1000.
Suzuki claimed that the GS1000 weighed in dry, perhaps with helium in the tires, at 499 pounds, though a more realistic curb weight with 4.8 gallons of gas in the tank was closer to 550. It turned the quarter-mile in less than 12 seconds, but what really counted was on the track, where it out-handled the competition. That got the attention of the other three of the Big Four.
The basic GS1000 slipped away after two years, but the engine/frame stayed on through 1982, last seen in the Katana model.