His management expertise and keen eye for talent produced champions in AMA road racing , dirt track , motocross and Supercross , and some of those riders went on to capture World Championships .
Gary Mathers may be the most successful figure ever in American motorcycle racing .
Gary Mathers ' management expertise and keen eye for talent produced champions in AMA road racing , dirt track , motocross and Supercross , and some of those riders went on to capture World Championships .
Gary Mathers may be the most successful figure ever in American motorcycle racing .