Newbie, introduction and matching numbers question

[Totus]

Hi my name is Brian 54 years old, live in Aberdeenshire and new to the site.

I have a BSA M21 1958, owned it for 3 years now, it's on a A  prefix reg which a
Has never bothered me but I'd like to know if it was a matching frame and engine numbers bike.

I've had a look at the dating numbers section and found that the frame number is correct for 1958 but the Engine number is 1957, is this proof that it's a non matching numbers bike?
Or is it possible the bike was assembled with an engine that had sat on the shelf for some time? the bike was registered in the first week of July 1958


Thanks in advance for any help

Brian

[Totus]

I didn't think my question above would be difficult to answer.

Let me try another angle, when the BSA engines were assembled did they get the engine number stamped on the as soon as they were completed then put on a shelf?  Or did they get numbered when the bike was assembled?

Thanks in advance for any help

Brian

[JulianS]

The only way, in the absence of any old documentation, to find if the engine and frame left the factory together as one bike is to get a dating certificate from the BSAOC. This will confirm what the factory despatch book says.

The link will tell you how.

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

[Totus]

Julian

Thanks for the reply, I had a look at that page and didn't know where to start.

Can anyone point Me in the direction of the librarian, I've had a look on the site but can't find a link to contact him/her

Thanks

[JulianS]

Use the form and complete it fully with the rubbings/photos requested. Then post it with the cheque and enclose a decent size and properly stamped return envelope.


http://www.bsaownersclub.co.uk/machine_dating/BSADCVR_request.pdf

[Totus]

Thanks for the link

Brian