Calthorpe - Sport
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Calthorpe D2-492-84-09
Photo ou archives : M. Woollett

Capacity : 500
Model : Sport
Production : 1939 -
Category : (R) Street Bike


500 Sport - 1939

The End of the line

Founded in 1909 in Birmingham, the Calthorpe marque achieved a worldwide reputation with its Ivory range. Powered by an own-make engine, the first Ivory (stylishly finished in ivory white) was a 350cc single launched in 1929. It proved so successful that identical 250 and 500cc models were added to the range.

Hard Times

But the 1930s were difficult times, and even a reduction in price – the company's slogan was "As good as the best and nearly as cheap as the cheapest" – failed to save the factory from closure in 1938. The name and the stock were bought by Bruce Douglas, nephew of William Douglas, founder of the Douglas motorcycle company, famed for its flat-twins.

Matchless Motors

Bruce Douglas already owned a factory that made components for the British aviation industry, which was then expanding rapidly under the rearmament program following the Munich crisis of 1938. Benefiting from healthy finances, Douglas decided that the time had come to invest in the motorcycle industry. The Calthorpe engines were then beginning to show their age, so Douglas decided to buy in power units rather than build his own. The best engines then available were the new overhead-valve Matchless units, with fully enclosed valve gear, so orders were placed for 350 and 500cc engines. However, very few examples of the new Bristol-built Calthorpes had been sold before Bruce Douglas halted production in order to concentrate on his aeronautical activities.


Engine: 498cc (82.5x93mm) Matchless air-cooled single-cylinder four-stroke

Power Rating: 20 hp @ 5200 rpm

Valves: overhead

Fuel System: Amal 25mm carburetor

Transmission: Burman separate 4-speed, chain final drive

Suspension: girder forks (front); rigid (rear)

Brakes: drum (front & rear)

Wheels: 3.50x19 inch (front & rear)

Weight: 348 lb

Maximum Speed: 85 mph

This Matchless-engined 500 was the last Calthorpe to be built by the company before production ended in 1939.

Motorcycle encyclopedia Moto Passion, realised by François-Marie Dumas, include almost 2000 photos presented with an exhaustive history of the motorcycles exhibited.

This unique collection has been realised with the participation of many specialists. With many thanks in particular to Yves Campion, Michael Dregni, Didier Ganneau, Jean Goyard, Helmut Krackowizer, Michel Montange, Christian Rey, Bernard Salvat, Mick Woollett, etc

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