Numbers..
BSR is the same as the AW3, has been, .75 and 1.33
BWR is .64 and 1.57. 1:1 is the middle gear , of course..
they used a German Sachs, hub for a while in the Mk3 bikes, their first 3 by 2 _ 6 speed
.0.73 and 1.36..
Both types would have a wider driver, capable of taking 2 cogs , side by side, the Sachs adopted the standard 3 spline cog,
just made a thinner 3/32 13, & a 15t that skipped every 5th tooth as a shift gate..
The Newer hubs adopted a Shimano 9 spline driver and the cogs for those can be a 12, to 16..
.....
Last edited by fietsbob; 08-26-17 at 11:29 AM.