CarBrandLogos archive · Kawasaki · 1969

KawasakiH1 Mach III

Five hundred cubic centimetres, three cylinders, and a chassis that could not keep up.

Photo: Chuck Schultz · CC BY-SA 2.0

The story

A defining chapter in Kawasaki history.

Explore the ideas, engineering and context that shaped the Kawasaki H1 Mach III, then continue into its specifications and place in the marque's lineage.

Origins

Kawasaki's brief in the late 1960s was simple and slightly reckless: build the fastest-accelerating motorcycle available and worry about the rest afterwards. The H1, launched in 1969 and sold as the Mach III, was an air-cooled 500cc two-stroke triple in a frame, and with brakes, that belonged to a substantially slower machine.

1969 Kawasaki H1 Mach III · Chuck Schultz · CC BY-SA 2.0

Design and engineering

It worked as advertised. The H1 ran the standing quarter-mile in times almost nothing else on two wheels could match, and it did so for less money than a 650 twin. The power arrived suddenly, well up the rev range, in a way that rewarded riders who were ready for it and punished those who were not; the frame flexed, the front end went light under acceleration, and the machine acquired a reputation — "the widowmaker" — that Kawasaki did nothing to discourage and which sold a great many motorcycles.

In production

Successive versions softened it. The frame was stiffened, the ignition improved, a front disc brake arrived, and the engine was retuned to be less abrupt, which made later H1s better motorcycles and less interesting ones. A 750cc H2 followed in 1972 with the same character and more of it.

Legacy

Emissions rules and fuel consumption ended the line by the mid-1970s — a large-capacity two-stroke road bike was becoming untenable — and Kawasaki's future had in any case already arrived in the shape of the four-stroke Z1. What the H1 left behind was a particular reputation for building the engine first and asking questions later, which the company has traded on ever since.

At a glance