Williamson Flat Twin
The Williamson Flat Twin was motorcycle made in Coventry, UK by William ('Billy') Williamson, who had been managing director of the Coventry-based Rex company. He teamed up with William Douglas (of Douglas Motorcycles to develop new prototype motorcycles under the name Williamson-Douglas and employed Billy's brother Harold as a test rider. Douglas had been developing a 964 cc water-cooled flat twin engine that could be used either for light cars or motorcycles.
Williamson Flat Twin
TR001 · CC BY-SA 3.0
- Name
- Williamson Flat Twin
- Founded
- 1912
- Headquarters
- Coventry
- Activity
- automobile manufacturer
- Dissolved
- 1920
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Documentary summary
The Williamson Flat Twin was motorcycle made in Coventry, UK by William ('Billy') Williamson, who had been managing director of the Coventry-based Rex company. He teamed up with William Douglas (of Douglas Motorcycles to develop new prototype motorcycles under the name Williamson-Douglas and employed Billy's brother Harold as a test rider. Douglas had been developing a 964 cc water-cooled flat twin engine that could be used either for light cars or motorcycles.
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wikidata · Q2953189 · wikipedia · Williamson Flat Twin
In this article
Overview
Overview
Billy Williamson fitted this engine into a frame with Douglas-Druid girder forks and a Douglas two-speed gearbox and a foot-operated clutch which was launched in 1912 at a cost of £82. In 1913 an air-cooled version was added to the range and in 1914 a kick starter was added. Production was halted by World War I and in 1919 the only engines available were JAP 980 cc air-cooled side valves, so Williamson redesigned the frame to fit. Unfortunately Billy Williamson suffered a fatal heart attack in 1920 after only twenty motorcycles had been produced.
Key facts
Key facts
• Name — Williamson Flat Twin • Manufacturer — Williamson Motor Company • Production — 1912-1920 • Wheelbase — 60.5 in • Engine — 964cc water-cooled twin • Dry Weight — 300 lbs
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- United Kingdom
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reference work
- “Williamson Flat Twin”, English Wikipedia, consulted as further reading
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authority record
- Wikidata, structured authority record Q2953189: Williamson Flat Twin
General reference · Wikidata
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The Encyclopedia exists whether or not anything is for sale. Corrections are recorded rather than overwritten, and every version of this record is kept. Published 16 August 2026.
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