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Felix was a motorcycle produced in 1924.
Based on a 350cc Raleigh, the machine was a special. It had been modified by Bill Bradley to have two-wheel drive, which was achieved by using a series of chains to take power to the front, while the rear-wheel drive was conventional. The concept of added traction made it suitable to run in a scramble.
There were rumours that the army would take on the design for further development, but that was not forthcoming.
What is notable is the fact that Rokon of America took up the Felix two-wheel drive idea in the 1960s, and the resultant machine could run almost anywhere.
Felix was a vertical four-stroke engine produced in 3-5hp single, 6-8hp twin and 10-12hp four-cylinder sizes 
The British Motorcycle Directory - Over 1,100 Marques from 1888 - by Roy Bacon and Ken Hallworth. Pub: The Crowood Press 2004 ISBN 1 86126 674 X