Pop off the snap ring and Look..
If... Its the pretty Much for you to look. .. If 9 spline ( a set by Shimano Standard ) then the 12 t is OK,
SA S3X and the SA for Brompton BWR use the 9 spline divers ,
But if its 3 spline, a Sturmey Archer, ( AW3, BSR,) and Sachs , Standard .. then its 13t at the smallest ...
Sachs made the 1st 3 by 2 Brompton Hub, for that they Sachs made a 3/32 thick Cog *, 13 & 15 as a Pair.
where SA ones for the 3 speed was An 1/8" thick one.
I've been using the shift gate 15t of the pair* .. every 5th tooth was shortened so 3 are not as tall as the rest.
Sram Bought out Sachs moved the German production machines to Taiwan ..
*54:15 on my Brompton 3 speed ..
I have My LBS order stuff I tell them what they Need to get, Sothey dont have to read My Mind ahead of time
Last edited by fietsbob; 11-09-15 at 06:03 PM.