The origins of the A.B.C. company lay in a small factory at Redbridge, near Southampton, where motorboat and aero engines were made before World War I.  In 1911 they moved to Brooklands to be nearer to the few firms that were making aircraft then, and soon afterwards added to their range flat-twin engines for motorcycles and cyclecars. Complete motorcycles were then made by A.B.C. Road Motors Ltd of Walton-on-Thames, and this company also made aero engines during World War I, including the famous Dragonfly, Gnat and Wasp. 

In 1919 A.B.C. began to make the Scootamota, one of the first motor scooters, and in 1920 a new company, A.B.C. Motors (1920) Ltd was formed to make aero engines, motorcycles and a new light car.  All were to be powered by flat-twin engines designed by Granville Bradshaw, who had been involved with A.B.C. since 1910.