Gnat light years ahead of time

The Gnat's success was largely due to the pioneering use of low-pressure tyres.

It's primitive by today's standards but was a leader

During the mid-1960s the Christchurch-based manufacturer of the Gnat was asked to build a prototype vehicle for possible use in space exploration.

J Cameron Lewis & Company Ltd built about 1680 Gnats in Christchurch, from 1965 until 1973. Following its success adapting low-pressure tyres for use in a light go-anywhere vehicle, Nasa, ordered a vehicle of its own design from the company.

"They told us they wanted to test one in Antarctica, for possible use in space exploration," Cameron Lewis said with an ironic laugh.

"And, like a bloody fool, I agreed to divert our engineers on to developing the thing for them."

Lewis does not now recall how the testing went. What he now finds amusing is that amidst the huge and complex challenges of being a small company manufacturing in New Zealand, he agreed to divert stretched resources to a machine to help Nasa.

Despite minor issues, farmers and fishermen received the Gnat with enthusiasm. Probably the first ATV, the Gnat pioneered use of low-pressure tyres to improve traction in the rough.

Honda, Yamaha and Kawasaki engineers visited Lewis, interested in emulating the design. Honda's homage was a 90cc straddle-ridden three-wheeler released on to the market in 1970. This design idea later morphed into the modern quad bike.

But Lewis does not have happy memories of his years manufacturing the Gnat.

As a trader, he had begun importing Japanese motorcycles and German sewing machines in the late 1950s. The most successful motorcycle was a Honda trail bike, set up for farm use.

These were hugely popular but often overloaded by farmers, who used them to carry bales of hay and other heavy loads.

The many accidents that resulted persuaded Lewis something safer needed to be designed for New Zealand farm conditions.

The initial idea was to do this plus export Gnats to Australia and Malaysia, to circumvent the then tight controls on importing machinery.

"Crippling import regulations led to the ludicrous idea of having a motor vehicle manufacturing industry here, such as the Trekka ute," he recalls.

"We had a reasonably successful product, but no access to dynamic testing facilities and mass manufacturing was well beyond us. Instead there was the nightmare of trying to maintain quality through batch manufacturing, which meant dealing with a multitude of suppliers of various components. The strain of those years just about ruined my health and my marriage."

Despite the difficulties, Gnats were used extensively on farms and became popular with fishermen.

The Mk 1 had a two-stroke Villiers engine which could start in reverse, incidentally providing four reverse gears.

The engine changed from the Villiers to a stationary Honda engine for Mk 2, but this had lubrication problems in the hills. A Mk3 was powered by a 9hp Briggs & Stratton with a Ford 10 gearbox.

Specifications

Max speed: 32 km/h

Weight: about 145kg

Ground clearance: 28cm

Carry capacity: 2 side by side passengers/272kg

Max climb angle: 1 in 2, or better, depending on the surface

Max tilt: 1 in 2, or better, depending on surface