Sturmey Archer 4-speed hubs can be identified by the markings engraved on the hub shell.
Early Sturmey Archer 4-speed hubs
The Sturmey Archer 4-speed hub started in 1939 with the AF close ratio 4-speed and the FM medium ratio 4-speed. Both of these hubs had primary and secondary gear trains.
Both of these 4-speed hubs were aimed at the club/racing cyclist.
In 1941 production was halted due to the war effort.
The Sturmey Archer FW 4-speed hub
The FW started in 1946 and was more suited to the commuter cyclist. It has compound planet pinions and two sun pinions which allow the drive to be run as a single simple gear train or a single compound gear train.
Reintroduction of the early 4-speed hubs
The AF 4-speed hub was reintroduced in 1947 as the FC.
The FM was finally reintroduced in 1952.
Availability of 4-speed hub parts
Although none of these hubs are now in production many parts are the same as used in the common AW hub so repairs can usually be made.
Some parts are now very hard to find such as low gear pawl pins for the FW hub and the dog clutch and secondary planet cage for the AF, FM and FC hubs.
I have pattern pawl pins which are indistinguishable from the originals. I also have a limited number of original NOS and good reclaimed dog clutches and secondary planet cages and some other hard to find parts in stock. So, in most cases I am able to repair and restore these hubs.
Please note – I am unable to supply obsolete parts as they are needed for repair work. Pattern parts can be supplied to UK customers only on an “as time allows” basis.