A top-selling model for BSA in the 1920s, the versatile Model B, or 'Round Tank', was used by just about every tradesman whose job required cheap personal transport. Popular with learners - the fact that the gearbox had only two speeds and that both brakes operated on the rear wheel were attributes guaranteed to re-assure novices - the reliable 250 cc side-valve engine provided many with their first motorcycling experience. Advanced features, for a lightweight, included all-chain drive and pumped lubrication, though the traditional sight feed and auxiliary hand pump were retained. A three-speed version - identifiable by its black tank - was added for 1926 and then the following year a wedge-shaped tank replaced the much-loved original.