Ah, Sturmey Archer....one of my favorite subjects.
1) Sounds like you have a 1956 alloy AW hub - same ratios as the steel shell
AW.
2) The Cyclo clusters seem to be the most popular - they show up on ebay
from time to time and I've even seen list members post one for sale
occasionally. Some other alternatives are: You can fit two dished SA cogs on
a 3-notch driver. Harris Cyclery (and some other shops) carry 3/32nd cogs -
Sheldon Brown is a fountain of knowledge about 3-speed hubs.
http://www.sheldonbrown.com/
>From: NortonMarg@aol.com
>To: classicrendezvous@bikelist.org
>Subject: [CR]Sturmey parts/service Questions
>Date: Mon, 17 Jun 2002 22:53:21 EDT
>
>I have what I thought was a Sturmey alloy 5 speed. It turns out on cleaning
>that it says 3 speed. There are numbers "56 10" (I presume means Nov.
>1956). My questions are:
>1) Are the internal gear ratios the same on the alloy as the steel hubs?
>2) Does anyone know a source for those 3 or 4 speed clusters that fit where
>the single cog goes?
>3) Is there a cogset that is any better (ratio-wise) than any other?
>4) Anyone service these things? In an ill fated attempt to remove the axle,
>some little thing went flying and I never found it. No idea what it was,
>but
>I figure it was probably necessary.
>5) Would I be better off with a 4 or 5 speed alloy hub? I'm thinking about
>the ratio spacing.
>Stevan Thomas
>Alameda, CA