At the 1970 British Commonwealth Games he won the bronze medal in the men's individual pursuit over 4000 m. Four years later at the 1974 British Commonwealth Games in Christchurch he won a bronze riding as part of the team pursuit. At the following Games in Edmonton 1978 he came 30th in the men's road race. Stockwell won his third bronze at the 1982 Brisbane Games in the men's team time trial. He competed at the 1972 Summer Olympics in the men's team pursuit finishing in 14th position.