BSA M20

When World War 2 began, BSA was Britain's major motorcyclle factory, with the proud boast that 'one in four is a BSA'. The firm had supplied the armed forces in World War 1 and as befitted a company that began as an armament manufacturer, had geared up to produce munitions as early as 1935. They would go on to become the biggest supplier of motorcycles to the forces, in the unlikely form of their model M20.

Originally launched in 1937, mainly as a sidecar model, the M20 used a 500cc side-valve engine in a heavy frame. BSA had been supplying the War Office with a variety of models for evaluation and in some cases purchase, since the late 1920s. The company originally submitted the M20 in 1936, only to see it fail, owing to heavy engine wear. Resubmitted the next year, it passed and a small batch was purchased in 1938.

The War Office then issued an official policy that favoured the machines already in service, whose reliability was well known, principally the Norton 16H and M20. Large quantities of the BSA model were bought. Heavy, bulky, slow and with limited ground clearance, the M20 had far from an ideal specification but it was rugged, generally reliable and was easily repaired. Special fittings included a long, spiked propstand for field use and a large headlamp, fitted with a blackout mask. In 1942, a shortage of rubber led to rubber hand grips being replaced with canvas fittings and footrests with simple metal ribs. A large air filter mounted on the tank and coupled to the carburettor by a hose was fitted for use in climates such as the African desert. As a result part of the rear of the tank had to be cut away.

Purchased for despatch and escort duty, the M20 served in many theatres of war. Over 125,000 were purchased by the armed forces. The finish consisted largely of applying khaki paint livberally, including the engine, tyres and even the saddle, with different camouflage schemes in various countries. Vast numbers of M20s were discharged at the end of hostilities and after gaining a new coat of paint they were snapped up by a transport-hungry public.

However, the model stayed in service in smaller numbers for many years in some cases as late as 1971. The vast quantities built mean that ex-WD M20s are still in use in many parts of the world and it is even possible to find that new spares are still available. The civilian model was manufactured until 1955, with its 600cc cousin the M21 soldering on until 1963, the last side-valve built in Britain.