Sunbeam S7 500 cc motor cycle, c.1950.

Incorporating an engine based on motor car lines, the Model S7 represented one of the most technically advanced designs to be adopted for motorcyles in the country. It was introduced by the B.S.A. Group as a progressive alternative to the long-estcablished, single-cylinder, chain-driven type of machine.

The S7 was designed by Erling Poppe, along with the S8 and S7 ‘Deluxe’, and based on the BMW R75. The S7 was produced between 1946 and 1948 updated by the S7 ‘Deluxe’ and S8 in 1949.

Before the Second World War Sunbeam had the reputation for first class workmanship, termed the ‘Rolls-Royce of single cylinder motorcycles’ and ‘the gentleman’s motorcycle’. However, the S7 was expensive and the cheaper S7 ‘Deluxe’ and S8 with a simpler design still didn’t sell very well. There were some problems in the design and the comfort aimed for was not entirely achieved. Eventually production of the S7 and the S8 ended in 1956.