Champion_Superbowl_Of_Motocross_Mike_Bell_American_Motorcyclist_October_1978 Published September 23, 2014 at 480 × 684 in Daily 70s Ad: Champion, ‘Superbowl Of Motocross’ (1978) Champion, ‘Superbowl Of Motocross.’ (‘American Motorcyclist,’ October, 1978)