[JimmieS]

Many thanks - will do.
Jim

[phutton]

You could try Russell at Chronometric Services:
http://chronometrics.co.uk/

P.

[JimmieS]

Hi John
Many thanks for your kindness in supplying the info. Much appreciated. Both are clockwise units.
Jim

[singleminded]

The important part is the rotation and the ratio..The numbers should relate to that but I havn't found a definative source yet.

[JimmieS]

Hi John
Many thanks for link and info. Will have a look and see what they are.
Jim

[singleminded]

http://www.vintagebritishcables.com/Smiths-Gearbox-Motorcycle.php
The numbers are identifiers, but I have no info..Have a look at the link above.
For Sunbeams with the drive on the right you need a clockwise rotation of the input and clockwise rotation on the output.
If you have clock in and anticlock out then it fits on the left of the bike...John

[JimmieS]

I have what I understand are two 1930s Smith front wheel speedo gearbox drives. One is stamped '25791' and the other '34121' on the cap below the split pin. Are these reference numbers, serial numbers or ?
Jim