In addition to the Spagthorpe Motorcycle Company's own factory racing team, there existed several privateer racing teams who in their own special ways contributed to the Spagthorpe Racing legend.

Belgium: The Tervuren Brothers

Belgian brothers Grönendäl, Läkenois, and Malinois Tervuren raced Spagthorpe Weimaraners during the 1920s.

Germany

Leon Berger raced various Spagthorpe models during the 1930s.