Vintage BMW Motorcycle Owners

Hi All,
I'm restoring a 1937 R12.
I'm trying to identify the frame number, but sadly it's quite obscure
due to corrosion.
The engine number is 9660. The frame should be prior to 1938 as it does not have the additional
brace added to the headstock. From what I understand anyway.

I'm still working on trying to identify the frame number using other non-destructive means.

I was wondering if by chance that engine number showed up in the register?
Who would I email to find out that info?
Thank you

Send info request with serial # to:

info.grouparchiv@bmwgroup.com

Tommy

The Sept 2021 issue of the UK BMW club magazine had an article about something called 'Scenesafe Frys Forensic Reagent.' It identifies the compressed molecules deep inside the metal and lifts the impression of the number to the surface. It is used by police for instance when id numbers have been ground off. It's not guaranteed to work but the writer, Christian Rohr succeeded in retrieving the engine number of his R 71.

I think it's Ammonium persulfate and Fluoride oxalate, if that helps.

Charlie.

There are two places where the serial number of the frame was stamped, depending on when the frame was produced.
You might not be looking in the proper place for the number, depending on the frame.
Early frames always started with the letter P followed by the number, and it was stamped on the frame on the left side, below the hole for the axle. My 1936 has the P and a stamped number in that position.
Later frames had the number stamped on the right side, on top of the upper frame rail, just before the the frame turns upward for the arms of the luggage rack. As seen on my 1941 R12.

Hello,
Here is drawing with possible location of R12 numbers. I hope it helps.