Born in Colne, Lancashire, England, Smith began in competitions as a trials rider, becoming so successful that he was offered a place on the Norton factory team.[1] After moving to BSA, he won the 1953 and 1954 British Trials Championship.[1] BSA asked Smith to compete in motocross racing which he did with such success that he soon began to concentrate on a motocross career.[1]
In the 1964 500cc Motocross World Championship, the defending champion, Rolf Tibblin, began the season strongly by winning five of the first six races of the season, but the 30-year-old Smith consistently scored points throughout the season and never finished below third place.[5] The championship wasn't decided until the final race of the season in Spain, where Smith took the victory to claim the World Championship by only two points over Tibblin.[5] His performance earned him the Motorcycle News 1964 'Man of the Year' award.[1][6] He successfully defended his crown the following year.[7] His 1965 championship win on the four-stroke enginedBSA Victor would be the last victory for this type of motor, as two-stroke engine technology dominated off-road racing for the next several decades. He finally announced his retirement in January 1972.[8]
Smith was an AMA director and Treasurer, and also involved in vintage motorcycle racing as an Executive Director and Assistant Treasurer of the American Historic Racing Motorcycle Association AHRMA, before resigning from AMA on 15 February 2008, followed by his resignation from AHRMA, as a result of irregular expense-account claims submitted by the then AMA Chairman.[10][11]
1From 1957 to 2002 500cc is the premier class. 2003 top class named motocrossgp which combine the top driver from 500cc and 250cc last year.2004~2013 MX1 and 2014 to today MXGP is the premier class,both use the 450cc 4 stroke bike.