Williamson were motorcycles produced from 1912 to 1920.
1912 The first machine made it debut and offered power with silence, and no vibration, courtesy of its 8hp flat-twin water-cooled engine, made for them by Douglas of Bristol. As it was part of their stationary engine range, it had a starting handle, like that of a car. It was a typical Douglas engine with side valves, gear-driven magneto and was installed low down in a long frame to drive a two-speed Douglas gearbox with all-chain drive.
1913-1917 For a list of the models and prices of cars see the 1917 Red Book
1913-1917 For a list of the models and prices of motorcycles see the 1917 Red Book
1913 An air-cooled version was added, but it did not sell as well as the quieter machine and had a tendency to over-heat. It did, however, continue to be offered as an option. Most models sold were water-cooled and used for sidecars.
1916 Production continued until that year, and then stopped until after the War.
1919 Late in the year they returned with the air-cooled flat-twin and a new model with the 771cc sv JAP V-twin engine and three-speed Sturmey-Archer gearbox with all chain drive.
1920 Only the V-twin remained, this being sold with the sidecar as a complete combination. It was their final year of production.