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Charles Redrup had been interested in both rotary and radial engines as early as 1904 and in 1912 he built a combination engine that was mounted in a motorcycle so that both sections drove the rear wheel by shaft.
After the end of World War I, he produced a design for a radial three-cylinder engine, rated at 2.75hp. His main interest was in engines, but in order to prove it successful, he commissioned a few complete machines. One such machine was entered and ridden by himself in the 1920 A-C. U. (Auto-Cycle Union) Six days Trial.
During 1921, the rights to the production of the Redrup engine were acquired by the British Radial Engine Co, who made motorcycles of that name.