8 June 2015

Sunbeam Motorcycles

Successful British company’s unique motorcycles were known as the Gentleman’s Machine

If you’re a British car enthusiast or ex-pat, the name Sunbeam will be a familiar one.

If you’re not, the Canadian household appliance manufacturer might be a more fitting product that immediately comes to mind.

John Marston began manufacturing bicycles on the suggestion of his wife Ellen in 1888; he adopted the trademark brand Sunbeam and continued building bicycles until 1936.

Marston experimented with adding an engine to one of his two-wheeled creations in 1903, but all did not go well. A test rider was killed, the project was shelved and he moved on to focusing on four-wheeled vehicles.

In 1905, the Sunbeam Motor Car Company was founded, but the car market did not exactly take off, forcing Marston to revisit manufacturing motorcycles in 1912 at the age of 76.

This venture was a success as the build quality was of a very high standard.

Sunbeam motorcycles were known as the Gentleman’s Machine.

After the First World War, Marston sold the company to Nobel Industries, which in 1927 amalgamated with Brunner Mond Ltd. (an outfit that would become well-known as Imperial Chemical Industries or ICI).

In 1937, the Sunbeam motorcycle trademark was sold to Associated Motor Cycles Ltd., who built Matchless and AJS motorcycles.

Six years later, AMC sold the Sunbeam name to BSA. The co-branded BSA/Sunbeam motorcycles were not built at the BSA factory in Birmingham but rather at a separate facility in Redditch, Worcestershire.

The pictured 1948 S7 model fitted with large balloon tires was designed by Erling Poppe, based on the BMW R-75 design BSA acquired the rights to after the Second World War.

BSA did not want the S7 to look like the German motorcycle with a horizontal flat twin engine so they fitted it with an unusual inline 500-cc twin engine, which powered the rear wheel, similar to the BMW, through a driveshaft.

For the home market they were available in black and mist green; for the overseas market they could be ordered in any colour. The downfall of this model was the worm-drive gears used to drive the rear wheel. BMW used the much-stronger bevel gears.

Sunbeam’s solution to reduce the gears from stripping was to reduce the engine output to 24 horsepower, which did nothing for postwar sales.

Motorcycle production ceased in 1956 and two models of scooters were available until 1964.

The Sunbeam Motor Cycle Club is one of the longest established clubs in England, founded in July 1924.

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