Mick Butler was perfectly correct in suggesting that the 7 indicated the
year of manufacture. There are plenty 2s, 3s, 4s etc around and this dating
also applies to Sturmey Archer's other models from the time. This system of
dating however only came in around 1932/3 - previously they had used a
serial number on each hub - these six figure numbers all date from pre 1932.
Post WWII four figure dating numbers were used indicating the month and last
two digits of year.
If anyone is interested in Sturmey Archer gears Tony Hadland's book The
Sturmey Archer Story is a must. It can be ordered mail order through
http://www.bikebook.demon.co.uk/
Hilary Stone, Bristol, England
Bruce Robins wrote:
> Thanks for chiming in with that bit of info about the K7. Your theory makes
> sense except for one thing. If the digit was the year of manufacture, then
> that means there must be K2s, K3s, K4s, etc, on the go as well. That might be
> the case but I haven't heard of any. Mind you, I hadn't heard of the K7 until
> I got this hub!
>
> I've looked at the 1930s online catalogues for Sturmey hubs and can't find any
> mention of a K7 there. If what you're saying is that the K7 stamped on the hub
> refers only to a date and not a model name, then it all ties in.
>
> Anyone else able to back up Mick's dating theory with some hard evidence?