ČZ factory-supported rider
Paul Friedrichs dominated the 500cc displacement class by winning seven out of fourteen Grand Prix events, defeating former World Champion
Rolf Tibblin and the defending World Champion
Jeff Smith. Friedrichs' victory marked the first time a motorcycle powered by a
two-stroke engine had won the premier 500cc division since the inception of the Motocross World Championships in
1957. Former two-time World Champion
Sten Lundin made his final World Championship appearance with a third place at the 1966 500cc Luxembourg Grand Prix. In an effort to keep pace with the rapid developments in two-stroke engine technology, the
BSA factory racing team constructed a new
BSA Victor motorcycle for Smith, which utilized a
four-stroke engine cradled in an ultra-lightweight, titanium
motorcycle frame. Unfortunately, the titanium frame was too brittle and broke regularly during competitions.
Torsten Hallman and
Joël Robert traded wins back and forth in a season-long battle for the championship that wasn't decided until the final race, when Hallman finally prevailed over Robert to clinch his third 250cc World Championship.
Åke Jonsson won the 250cc Luxembourg Grand Prix for the first overall victory of his career. == Grands Prix ==