B31 Rigid Dating

[sidewaysid]

Hi Everyone

How do I go about finding the true year of my newly acquired frame, it seems the guy told me it was 1946/47 but according to some parts in BSA books it seems more 1959 which would be better as my motor is 1950 (I think)

Thanks Guys

[JulianS]

If the number starts XB31 then it is either 1946 or 1947.

If YB31 then it is 1948 season.

If it is ZB31 then it is either 1949, 1950, 1951 or 1952 season.