Questions? Looking for parts? Parts for sale? or just for a chat,

The WD Motorcycle forum

WD Motorcycle forum
Start a New Topic 
BSA WM20 identification

Hi looking to verify ex UK military bike to see if frame no/engine no are original any help advice welcome
Frame no 31/BW/24
Eng no 81722

Many Thanks In Advance

Re: BSA WM20 identification


The frame number doesn't look like BSA WM20 at all.

Do you have perhaps a few photos of the numbers?

Kind regards,

email (option):

Re: BSA WM20 identification

Does the frame number indicate a Base Workshop? ie replacement frame? Ron

email (option):

Re: BSA WM20 identification

'FAU' with a 'C' suffix is a 1965 Nottinghamshire series so the bike is likely to have had a post-war registration...It will be a job to find it in the 'Key Cards' though unless they used the engine number.

No brass plate inside the toolbox ?

Re: BSA WM20 identification

WD BSA M.20 with a Nottingham registration almost certainly sold by Dawson Motors from a Chilwell auction.

email (option):

Re: BSA WM20 identification

These 31/BW/.. numbers do seem to be a rebuild number presumably stamped on a new replacement frame or a frame with a previous number filled off, is there a flattening or any file marks under the number?

31/BW/24 is listed as a frame number in the post war key cards.

Card 351A

72YD72 31/BW/24 4564435 C13290 1st Foresters 26 6 63 3.61

C 4564435 would originally have had the frame and engine WM20 54926, but it could just be the number on a random tank fitted during a rebuild?


email (option): robmiller11(a)

Re: BSA WM20 identification

A high resolution scan of the relevant Key Card (with appx. 17 bikes on it) can be bought from me.

Nice to frame, and hang on the wall, or keep with the bike.



email (option): welbike@welb**

Re: BSA WM20 identification

That's the one on e bay isn't it?....Subject of another thread here....Ian

email (option):

Nieuwe pagina 1