Norton motorcycle englne and frame dating
On most BSA's the frame number is located in the following places.
It is always stamped; raised numbers are casting part numbers.
Some BSA & Triumph models had frame numbers near the front engine support - check your frame to or identification numbers.
Below you will find both Triumph engine and frame numbers for Triumph 650 unit twins from 1963-1968 and a Triumph 650 models list from 1963-1968.
all A series models have A7 or A50 prefixes with the exception of the Rocket Gold Star and Super Flash.Owners with late model BSA's can easily identify the month and year of their machine as the factory adopted a dating system for frame and engine numbers for the 1969 season models.As with all previous BSA seasons the model year started after the factory shutdown in July so that 1969 models were those made from August 1968, through to July 1969.If the original factory record is illegible or absent, the charge for the service will be refunded.Any data provided are for information only and could be liable to transcription error.