Seeley entered his first race in 1954 at Brands Hatch, a one-hour endurance event, riding a solo 500 cc BSA Star Twin borrowed from a friend, where he completed 42 laps during the hour.
In 1960, Seeley with his friend - mechanic and employee Wally Rawlings - bought their first sidecar outfit, and ex-Eric Oliver machine based on a Manx Norton, entering their first race at Snetterton in April 1960.