1950 Douglas Mark IV

Updated August 7, 2026

VIN: 7028/4 Engine: 350cc One owner for the last 30 years. The 1950 Douglas Mark IV was a British flat-twin motorcycle known for its advanced and comfortable ride, achieved through innovative torsion-bar rear suspension and leading-link front forks. It featured a 348cc OHV flat-twin engine and was visually distinguished by teardrop-shaped rear toolboxes, a front mudguard mounted to the brake plate, and frame-mounted pillion footrests. While not a speed demon, it was a stable and well-handling touring bike. The 348cc overhead valve (OHV) flat-twin engine was mounted across the frame, giving the bike a low center of gravity and inherent balance. While not a high-performance engine, it was notably smooth and reliable. Suspension: The MK4 was celebrated for its advanced running gear, which contributed to excellent handling and a smooth ride. Douglas was a British motorcycle manufacturer from 1907 to 1957 based in Kingswood, Bristol, owned by the Douglas family, and especially known for its horizontally opposed twin cylinder engined motorcycles and as manufacturers of speedway machines. Several German manufacturers began making motorcycles with the Douglas layout when engine manufacturer BMW made its M2B15 flat-twin proprietary engine available in 1920.[20] The M2B15 had been developed from the reverse engineering of a Douglas motorcycle engine. Engine number 7028/4. Frame number 8190 4/13. Gearbox number 5097. Could use a new centre stand (which is why I've used timber to display her).

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