Eric Offenstadt Kawasaki 500 Monocoque Racer

Eric Offenstadt
Kawasaki 500 monocoque racer

With Phil Aynsley

In this article, we take a look at the Kawasaki 500 GP motorcycle built and successfully raced by Frenchman Eric Offenstadt.

The advent of (relatively) inexpensive two-stroke engines in the late 1960s and early 1970s began to democratize the 500cc world championship grid. Instead of an MV Agusta in the hands of Agostini, Panani, Bonera or Read leading a next pack from the house of Norton Manxs by a few minutes, an increasing number of this pack were now mounted on various two-stroke engine machines , and since Jack Findlay’s victory in a Suzuki at the Ulster GP in 1971, winning races.

It wasn’t just factories like Suzuki and Kawasaki that put two-stroke-powered bikes into service. Enterprising privateers/engineers saw that it was possible to take a 500cc two-stroke road bike engine and modify it very cost-effectively to deliver reasonably competitive power. If it’s not as much or as reliably as the MVs, then at least a lot more than the four-stroke singles they used.

Suzuki’s 500cc Titan/Cobra parallel-twin was one of those favorites, as was Kawasaki’s 500 H1 triple. Frenchman Eric Offenstadt ultimately took a slightly different approach. Offenstadt had started racing at 19, in 1958, and in 1961 won the French 175cc championship. Another successful year followed before he moved on to Formula 2 and 3 car racing.

He returned to motorcycling in 1970 and supported by the French importer Kawasaki, won the 1000 km endurance race at Le Mans and finished first in the 500cc class at the Bol d’Or. Along the way, he also twice finished in the top ten of the 500cc World Championship. In 1971 he finished sixth in the championship on a Kawasaki triple housed in an alloy monocoque chassis of his own design.

His ingenuity was on full display in 1973 when (spurred on by the French Motorcycle Federation) he entered this bike, again using his own monocoque chassis. However, to get around the H1’s engine width problem, he used a 750 H2 road bike engine that had one cylinder removed. Alloy wheels and a front fork from its own SMAC brand were also fitted. He scored fourth and fifth place finishes during the season. Not bad for a hacked road bike!