Your Sturmey Archer hub can offer a good way to decide on the age of your bicycle. You can find the hub date displayed clearly on many hubs. Early hubs are more difficult to date accurately.
I have compiled the information below from hubs that I have actually seen either in person or from a clear picture. If you have a hub which contradicts any information on this page I would like to hear from you.
Hubs after World War 2
From 1947 to 2000 Sturmey Archer clearly marked their hubs with a date. This hub date marking will show the last two figures of the year and the month.
From 1932 to 1940 Sturmey Archer used the model designation with just the last digit of the year.
1930 and 1931 hubs were marked with an “A”. I have seen K hubs and KB hubs with this marking.
Assigning a Hub Date To Earlier Hubs
Before 1930 Sturmey Archer gave each hub an individual serial number. I have been researching these numbers for some time. I am now able to share some results of my research here.
Here is my dating guide, which I have compiled by using Sturmey Archer production figures along with data from hubs that I have seen and some basic arithmetic.
This is only a rough guide. Please allow for error of one year in each direction as I am still researching this.
Estimated Dating Guide
1921 ??-25000 (lowest number I’ve seen is K11857)
1929 840000-end of run then undated until 1932 (highest number I’ve seen is K854620)
Note About Undated Hubs
There were no date marks, or numbers that could be used to date hubs, in 1930-1931. These were instead marked with the letter A, which has lead many to presume erroneously that they have the much earlier and scarcer A hub. We can have reasonable confidence when we assign K hubs marked “A” to this short period.
It is tempting to assign other undated hubs to the second world war, but we would sometimes be mistaken. Some of the undated A series and F series hubs that I have seen are clearly from the period 1951-1965. As a guide: an undated hub with threaded driver and black left ball-cup would be wartime, but with a 3-splined driver and silver ball-cup it would be 1950s. Why they are undated remains a mystery.