A 598cc engine was used in the Model 85 Redwing (previously Model 80) from 1929 to 1930, and the Model 60 (previously Model 3) from 1928 to 1935. The Model 100 engine was largely a development from the Model 60. The earlier engines had compression ratios of either 5.4:1 (Model 60 pre-1930) or 7.0:1 (Model 85 and Model 60 post-1929). The frame is derived from the 1928 Panther and the tank from the 1932 Model 50. The history of the development of the Model 100 is as follows.
1937 - New fully chromed fuel tank with red and black lined cream panels and snarling Panther logo. This was the last year of the "Redwing" Model 100
1938 - Kidney-shaped rocker cover introduced. Redwing designation dropped
1939 - Miller Dynamag replaces
BTH magneto. 3.5 gallon tank introduced
1940 - Production ceased for
World War II 1946 - Production resumed after war. Lucas magneto introduced.
1947 - Dowty Oleomatic forks introduced
1950 - Manual advance/retard reintroduced
1952 - Lucas Magdyno introduced
1954 - Swinging arm Model 100 introduced. Four gallon tank. Panther forks.
1955 -
Amal 376 introduced
1956 - Amal 389 introduced. Heavy duty, sidecar trail. Panther forks.
1957 - Swinging arm Model 100 de luxe introduced. Last year of rigid Model 100. Dualseat as standard.
1963 - Model 100 last manufactured. It was the end of the line for 600 cc four stroke heavyweights. The 650 cc Model 120 continued for another three years ==Sources==