BSA Motorcycles were made by BSA Cycles Ltd, under the BSA parent, until 1953 when the motorcycle business was moved into holding BSA Motorcycles Ltd.
The first instance of intention to produce motorcycles was reported in The Motor Cycle, a British motorcycling journal, in July 1906.
The first wholly BSA motorcycle, the 3½ H.P. was built in 1910 and displayed at the first Olympia Show, London on 21 November in that year. Sir Hallewell Rogers, BSA Chairman, had informed the shareholders at the Company's 1910 AGM in Birmingham "We have decided to put a motor-bicycle on the market for the coming season .... These machines will be on exhibit at the Cycle and Motor Show on November 21st, after which date we look forward to commencing delivery".
The machines were available for the 1911 season and entire production sold out. BSA had previously acquired a commercially available engine in 1905 and fitted it to one of their bicycle frames and discovered at first hand the problems that needed to be overcome. BSA Cycles Ltd was set up as a subsidiary company in 1919 under Managing Director Charles Hyde to manufacture both bicycles and motorcycles.