Whooooo Hooooo !! Both an ASC and and FM !! Lucky You !! Congratulations !!
About the sprocket question , funny you should ask . I read this paragraph only yesterday . So , I knew just where to find it !
( and if you have those wonderful hubs , you should think about buying a copy of this book ! try Amazon.com , or try the U.K. / Great Britain branch of Amazon.com , or try http://www.hadland.net )
From the book , "The Sturmey Archer Story" , by Tony Hadland , first published December 1987 - page 124 :
" A Change Of Sprockets
Sturmey-Archer announced that, from 1951, all hub gear sprockets would be of the present three-lugged type. It replaced the hitherto standard threaded sprockets and also the 'club' type twelve-lugged sprockets. The three-lugged type is today used by other hub gear and coaster manufacturers such as Fichtel & Sachs and Shimano.
It seems that it took some time for the new style sprockets to reach the trade ; the 1952 Brown Brothers Catalogue stated that none were yet available.
At first the new sprockets were supplied only in sizes from 14 to 20 inclusive. However the 14 and 15 tooth sprockets could not be used with the AW, AB / ABC or FW if a 1 1/2 inch ( 38 mm ) chainline was required. To achieve this it was necessary to fit a different ball ring, ball cage and dust cover ; otherwise the chain would foul the dust cover. "
And may I add , it's a very handy book to have around !
Raoul Delmare
Marysville Kansas
> Anybody know when S-A converted from 12 spline to 3 spline? And if you're
> really into it, why did they do it?
>
> Craig Montgomery in Tucson where I'm about to build up an ASC and an FM.