The BSA Bantam traces its roots to the German DKW RT125. BSA mirrored the engine layout to put the gear lever and kick-starter on the right, as British riders expected. Introduced in 1948, the D1 used a 123cc two-stroke single, a three-speed gearbox and, at first, a rigid rear frame.
The Bantam was never a single unchanging design. The D3 grew to 148cc in 1954. From 1956 the range gained a frame with swingarm rear suspension, and the 1959 D7 brought a 175cc engine, improved front forks and larger brakes. Each step developed the same basic idea: a modest motorcycle for everyday journeys.
A D1 in postal-service livery in the UK National Motor Museum collection recalls the machine’s working life, beyond its present appeal to collectors. Production continued until 1971. Across those years, the Bantam moved from a postwar transport solution to a family of progressively refined lightweight motorcycles.