The 82 bhp 903cc four-cylinder machine changed the world of motorcycling, beginning the horsepower war between the leading sports bike manufacturers that has seen horsepower increase by 150% and weight fall by 20% in the ensuing four decades.
Whatsmore, it did so at a very affordable US$1895 and was one of the key motorcycles which established the reputation of reliability and performance for Japanese motorcycles.
The Kawasaki 900 was originally developed as a 750 by Kawasaki designer Gyoichi Inamura and his team in the late sixties, but the surprise appearance of the Honda CB750 in 1969 meant that Kawasaki elected to wait and further develop its motorcycle as it did not wish to be seen doing a "me too", and the engine was subsequently enlarged to 900cc.
A decade after the Z1 was launched, I attended the launch of the "next" Kawasaki 900, the GPZ900R at Laguna Seca in California, and I was able to ride the original Z1 back-to-back with the GPZ900R - the contrast was stark, with the Z1 having so much low down torque that it felt like it had a truck engine in comparison to the high revving GPZ.
Kawasaki intends to tour an exhibit of historic motorcycles from the Z series around Europe over the coming year, culminating in a special exhibition in October during the Intermot show in Germany.