1931 Sunbeam 493cc Model 9
Registration no. WX 7980
Frame no. D10214
Engine no. LL5737
Sunbeam had begun experimenting with overhead valves on their factory racers in the early 1920s and these duly appeared on production models in 1924. The new 500 roadster was known as the Model 9 while its race bike counterpart, which could top 90mph, was accordingly designated the Model 90. The overhead-valve Model 9's frame and cycle parts, which had much in common with those of Sunbeams larger side-valve models, evolved slowly. Changes to the engine were confined mainly to its top-end. The early flat-tankers featured a straight-ahead exhaust port, a peculiarity that necessitated the adoption of a bifurcated down-tube, while later on in the 1920s Sunbeam followed the then-fashionable trend to twin-port heads before reverting to a single-port design. Pushrod enclosure had arrived by 1930 to be followed a couple of years later by partial enclosure of the rocker gear.
Boasting the chromed fuel tank offered for 1931 only, this twin-port Model 9 benefits from extensive refurbishment; the engine, gearbox, forks and wheel bearings having been overhauled in October 2008. Like many Model 9s WX 7980 has been upgraded with parts from the Model 90 racer, boasting the latters carburettor and sports mudguards, together with a special rear wheel stand. Taxed and MoTd, the machine is described as in generally very good condition and offered with old-style logbook and Swansea V5C document.