Featuring advanced Kawasaki technology, the Z1 completely redefined the world of high-performance motorcycling. During development its code name was New York Steak. The letter Z was chosen because as the last letter of the alphabet it represented the most extreme, and the 1 stood for number one in the world. The Z1 was the first mass-production sports bike to feature a DOHC, 4-cylinder engine — technology found only on factory racing machines or limited production sports bikes. Displacing 903 cc, the Z1 was not only the fastest production motorcycle of its era, its reliability and durability were equally impressive. Four mufflers accentuated the Z1's slim, sexy and sleek design. The Z1 became a huge sales success in its target market of North America and also in Europe, and was equally successful on the racetrack. Thus began the legend of Z — a legend that continues to this day.
During the 70's, café racers with racing inspired designs were all the rage. The Z1-R, successor to the mighty Z1, was a special café racer version of the Z1000. The Z1-R was designed in the U.S., the main market for the Z-Series. It featured a stunning silver livery and unique styling never before seen on a large displacement sports bike. A slim fuel tank accentuated the massive black engine, and a bar-mounted bikini fairing advertised the R-model's high performance. The Z1-R was also one of the first sports bikes to feature cast alloy wheels. Instead of the four mufflers of the Z1, the Z1-R used a 4-into-1 exhaust. The Z1-R heavily influenced the design of future Z-Series machines.
The Z-Series machines established the popularity of the air-cooled In-line Four. However, the series continued to evolve. The Z1300 was powered by a revolutionary, liquid-cooled In-line Six displacing an incredible 1,268 cc, the largest of its time. Harnessing the engine's massive power was a robust shaft drive. This flagship model boasted chassis and exterior components that were of the highest quality and performance. At 300 kg, the weight of this machine was equally impressive — in spite of this, test riders were seen wheelying the bike during its press launch. A road sport model built for fun, the Z1300 had so much power that it ran afoul of the West German horsepower regulations for motorcycles. The Z legend was now firmly established.
Based on feedback from Kawasaki's superbike racers, the 2nd generation Z models began with the Z1000 (J) in 1981. The Z1100GP, based on the Z1000, featured a larger 1,089.9 cc engine and greatly improved comfort. Its rectangular headlight and black engine and mufflers gave it a very sporty image. It also featured a unique rectangular instrument panel. The Z1100GP was also one of the first motorcycles of its era to offer fuel injection (K.E.F.I.: Kawasaki Electronic Fuel Injection) — technology made available on production bikes only by Kawasaki at the time. Compared with carburettors, this system allowed more precise engine management by adjusting fuel delivery according to changes in atmospheric pressure and temperature. The results were more power and improved fuel economy.
In North America, the main market for big-bore sports bikes, superbike racing using highly modified production bikes was even more popular than World GP and attracted some of the world's top riders. In 1981 Eddie Lawson won the championship for Kawasaki on a factory Z1000S. The Z1000R was built to commemorate that victory. The "Eddie Lawson Replica" was painted the same lime green as the Z1000S, and was a very popular model around the world. Like the Z1000S, the R model came with a Kerker 4-into-1 exhaust, a stepped seat and reservoir-equipped rear shocks.
In a sense, the Z1000 represented a return to the Z-models' roots. Rather than track performance and ultimate horsepower, the Z1000 delivered the traditional virtues of the Z-bikes: a sports bike that prioritised the rider "fun factor." The Z1000's 953 cc liquid-cooled 4-cylinder engine was based on the Ninja ZX-9R power plant. Featuring a special cylinder head and fuel injection, the engine was tuned for more low- and mid-range torque. The four stylish mufflers were reminiscent of the original Z1, and the large-diameter, steel-tube diamond frame was fitted with top-shelf suspension components for responsive handling. Ultra-modern styling cues included an angular headlight and a sexy and compact tail cowl, giving the bike an aggressive look and creating a new genre: the Supernaked.
This highly refined 2nd iteration Z1000 was based on the earlier Z1000 that had received rave reviews in Europe. Chassis upgrades included an all-new steel-tube diamond frame that incorporated a new aluminium sub-frame and mounted the engine as a stressed member, and a 25 mm longer wheelbase. Displacement remained unchanged at 953 cc, but improvements to the intake and exhaust systems resulted in more low- and mid-range torque. Other upgrades included radial-mount front brake calipers, and lightweight front and rear petal discs offering superior heat dissipation. An ABS version was also offered. The all-new exterior design included integrated radiator guards accentuating the Z1000's concentrated, massive image.
To take the Supernaked concept even further and make the 3rd iteration Z1000 even more fun to ride, Kawasaki's engineers discarded the earlier method of using an existing superbike platform and instead started from zero. They designed an all-new 1,043 cc engine tuned for hard-hitting low- and mid-range torque. Even the sound from the airbox and intake ducts during acceleration was used to enhance the ride feel. The chassis featured a new aluminium twin-tube frame for responsive handling and light weight. Another interesting feature was the Horizontal Back-link rear suspension that contributed to mass centralisation and improved manoeuvrability. A low-profile front cowl and high tank were complemented by specially designed wheels and stylish front fork guards, giving the new Z1000 a powerful, dynamic form.
The model concept of the 4th iteration Z1000 could be described with the keyword sugomi*. Visually, the new model’s sugomi design advanced the mass-forward crouching concept of its predecessor. The low-positioned head cowl, aggressively upswept tail, and leaner design were reinforced by tighter-fitting bodywork, contributing to an even more dynamic form as well as a higher quality fit and finish. More direct response from both engine and chassis brought riding excitement to a new level. The crisp response offered riders a very linear connection to the rear wheel and a satisfying surge of acceleration, while sharper handling and superb brake performance facilitated hard, sporty riding – both character traits that found favour with expert riders. Cutting-edge features like the new SFF-BP (Separate Function Fork – Big Piston) front suspension and Kawasaki’s first LED headlamp were other points of note. Thanks to its sugomi concept, the Z1000 took a significant step forward in both looks and feel.
*Sugomi describes core performance and styling elements found in Kawasaki’s Z supernaked models. Imbued with sugomi, their performance excites; a ride on a Z supernaked is a visceral experience that stimulates the senses; engine and chassis tuning deliver a high level of control. Sugomi is also evident in their sharp styling, dynamic crouching form, and distinct silhouette.