C15 date

[BOB M]

Sorry to be a pain! but I don't understand the dating formula. I have a BSA C15 without any paperwork/reg. The engine number is
C15 27702 and the frame is C15 6650.

Thanks for your help.
Bob M

[JulianS]

You can date the bike on the BSAOC website;

http://www.bsaownersclub.co.uk/machine.html

You will see that the frame is from the 1961 season but the engine is earlier and comes from the 1959 season.

[BOB M]

Thanks Julian