Motorcycling Australia Museum

1949 Rotrax JAP

Speedway’s staple fare

Despite the various claims from around the world as to exactly when and where speedway racing started as an organised sport, the advent of the British Speedway league in 1930 was the factor that catapulted oval dirt track racing into the big time. It create a stampede of riders and mechanics from Australia. At a time when the weekly basic wage was around $6, top riders could earn $200 per night in England – and race seven nights a week. Crowds frequently exceeded 80,000. The undisputed ‘king of the skids’ in these formative years was Queenslander Vic Huxley. From the moment he set foot in England, Huxley was without peer and in 14 years of racing was only injured once – when his foot became entangled in the chain of his bike. He began racing on a converted road-going AJS before changing to the almost universal 350cc Harley Davidson ‘Pea Shooter’, then to the flat-twin RA Douglas (which was designed by an Australian, S.L.Bailey), the 500cc Rudge and eventually the ubiquitous J.A.P. During the height of his career in Britain, the Huxley stable contained up to seven machines that were ferried around the country, maintained by two fulltime mechanics. With earnings of well over $10,000 in a single season, Huxley was reputedly the highest-paid sportsman in the world.

The outbreak of World War Two burst the speedway bubble, causing the cancellation of the 1939 World Championship, but it took little time for the sport to bounce back when the hostilities ceased. Once again, Australians were to the fore. Vic Duggan carried off all the major 1947 titles and looked a certainty for the World Championship when the event was sensationally cancelled by the promoters owing to the non-availability of US riders.  Duggan’s machine, and that of his brother Ray, was something of a revolution, being constructed of lightweight aircraft-quality T45 tubing. The Duggan design was quickly copied by several manufacturers in England, most notably by the London-based Rotrax concern. Supplies of quality tubing were extremely hard to come by in these frugal times, and Rotrax relied mainly on salvaged material from ex-wartime aircraft. One factor never changed – the powerplant.

The long-stroke JAP (for J.A.Prestwich) had changed little since the 1930s. JAP manufactured a large variety of engines for all sorts of applications, the bulk of production destined for industrial purposes, but they also produced a large variety of designs (included a patented desmodromic version) for motorcycle use. The speedway motor was originally adapted from a road racing unit by Stan Greening and top rider Wal Phillips. Designed to run on methanol fuel, the cast iron cylinder barrel and head were shaved of all superfluous fins and the oil system was by total-loss Pilgrim pump. After World War 2, JAP concentrated mainly on producing industrial engines until the company was old to Villiers in 1957. The rights to the manufacture of the speedway engine were old to George Greenwood, who persevered with the basic design until the 1960s. By this time the JAP’s domination was under severe threat from the Czechoslavakian ESO engine, which developed a similar horsepower figure (around 50 bhp) but had a far greater engine life. The basic JAP design was even modified to a four-valve configuration in the 1970s but its glory days were, by then, well over.

This particular Rotrax JAP spent its early days at Rowley Park in Adelaide before coming to Sydney where it was raced by John Bowerman. It spent many years mounted on the wall of artist Tim Storrier’s studio before he donated it to the National Motor Racing Museum.

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