Complex sentence: He was a champion rider at home and abroad during the 1920s and early 1930s and helped organize speedway racing on the east and west coasts of America, later becoming an AMA referee and a member of the competition committee.
Split into simpler sentences: He was a champion rider at home and abroad during the 1920s and early 1930s. Elder helped organize speedway racing on the east and west coasts of America and later became an AMA referee and a member of the competition committee.