The model number is in effect the motor number of a bike. The motor number is stamped on the left crankcase. The numerals of the motor number preceding the letters indicate the year. The letters indicate the size and type of the motor.

For example:
41EL2037 would be a 1941 model with a 61" OHV motor.
38U1863 would be a 1938 model with a 74" SV motor.

Below is a list of some of the motor designations:


Model Years Description
D 1929 - 1931 45" SV
DL 1929 - 1931 High Compression 45" SV
DLD 1929 - 1931 High Speed 45" SV
E 1936 - 1950 Medium Compression 61" OHV
EL 1936 - 1952 High Compression 61" OHV
F 1941 - 1950 Medium Compression 74" OHV
FL 1941 - 1965 High Compression 74" OHV
FLE 1955 - 1965 Special cam police 74" OHV
FLH 1955 - 1965 High Compression Sport 74" OHV
G 1937 - 1963 Servi-Car with tow bar
GA 1937 - 1963 Servi-Car without tow bar
GD 1937 - 1941 Large body Servi-Car without tow bar
GDT 1937 - 1941 Large body Servi-Car with tow bar
R 1932 - 1936 Low Compression 45" SV
RS 1932 - 1936 45" SV with Side Car
RL 1932 - 1936 High Compression 45" SV
RLD 1932 - 1934 High Speed 45" SV
RLDR 1935 - 1936 High Speed Race 45" SV
U 1937 - 1948 Medium Compression 74" SV
UA 1939 - 1940 Low Compression US Army 74" SV
UH 1937 - 1941 Medium Compression 80" SV
UL 1937 - 1948 High Compression 74" SV
ULH 1937 - 1941 High Compression 80" SV
V 1930 - 1936 Standard Compression 74" SV
VHS 1934 - 1936 Medium Compression 80" SV
VL 1930 - 1936 High Compression 74" SV
VLD 1930 - 1936 High Compression 74" SV
VLH 1934 - 1936 High Compression 80" SV
W 1937 - 1952 Low Compression 45" SV
WL 1937 - 1952 High Compression 45" SV
WLA 1940 - 1945
1949 - 1952 US Army Low Compression 45" SV
WLC 1942 - 1943 Canadian Army Low Compression 45" SV
WLD 1937 - 1942 High Speed 45" SV