Undated Sturmey Archer hubs are thought to date from 1940-1. They generally have all the features of the pre-war hubs - square axle key with slightly different axle, clutch and clutch spring and seem to come on bikes from those years. Pre-war 4-speeds also have several other parts different too. I have had an AM dated 1937 and an AW dated 1938 and several hubs dated 1939. The pre-war dating system used a single numeral to indicate the year unlike the post war system with a month number and decade/year number.
Hilary Stone, Bristol, England
Mike Self wrote:
> Does any one know when the AW hub started being stamped w/ dates?
>
> I have one which just says "Patent applied for" but has no date stamped. It's
> on a Nottingham built Raleigh Gazelle (pre Robin Hood) built between from
> 1938-44 (per Sheldon's site)
>
> I might want to use it in a future lightweight project.