The Z1 Kawasaki was a motorcycle

Motorcycle

A motorcycle is a single-track, two-wheeled motor vehicle. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions.Motorcycles are one of the most...

 introduced in 1972 by Kawasaki Heavy Industries

Kawasaki Heavy Industries

is an international corporation based in Japan. It has headquarters in both Chūō-ku, Kobe and Minato, Tokyo.The company is named after its founder Shōzō Kawasaki and has no connection with the city of Kawasaki, Kanagawa....

. It has sometimes been described as the world's first superbike. The Z1, along with Honda's CB750

Honda CB750

The Honda CB750 is a motorcycle built in several model series between 1969 and 2003 and 2007 that is recognized as a milestone for Honda's successful introduction of a transverse, overhead camshaft inline four-cylinder engine that has ever since been the dominant sport bike configuration...

 from 1969, introduced the four-cylinder, across the frame, disc-braked layout to a wider public. The Z1 was groundbreaking in that it combined many different elements which previous motorcycles had used into one performance package.

History

The Z1 Kawasaki was developed in strict secrecy under the project name "New York Steak". Some years previously, Kawasaki, already an established manufacturer of two-stroke

Two-stroke cycle

A two-stroke engine is an internal combustion engine that completes the process cycle in one revolution of the crankshaft...

 motorcycles, decided to make a 750cc 4-cylinder 4-stroke sports motorcycle; they were beaten to the market place by the Honda CB750

Honda CB750

The Honda CB750 is a motorcycle built in several model series between 1969 and 2003 and 2007 that is recognized as a milestone for Honda's successful introduction of a transverse, overhead camshaft inline four-cylinder engine that has ever since been the dominant sport bike configuration...

. Apparently, the bosses at Kawasaki disapproved and ordered their designers to come up with something better.

Stone was an Australian film that featured several Z1s ridden by a post-Vietnam veteran's outlaw biker gang.

Design changes

The basic design of the Z1 remained relatively unchanged until 1975, when the 903cc "Z1-B" was introduced, with changes including power output, improved suspension, a stiffer frame, deleted automatic chain oiler, revised styling (essentially paint scheme and side cover nomenclature), and improved braking.