Originally Posted by
bargainguy
If it were me, I like the 3-speed hub best of your listed choices. Automatix looks nice but 10mm OLD difference is pushing it IMHO, even with steel.
OK, going from memory here, but isn't there a SRAM S-RF5(W) with 111mm OLD? I seem to remember Brompton users going for this 5-speed hub because of the compatibility with existing Brommie rear triangles, which are 112mm OLD if I'm not mistaken.
10 mm going too far? Damn.
That restricts the options CONSIDERABLY.
(Also, the coaster brake 5-speed Sturmeys are 127 mm OLD. If I come up with a rear rim brake, the non-brake 5-speed one is available in 111, but my goal is to minimize the amount of rim brakes on this bike as it is - front at most, and I wouldn't mind replacing that with a drum eventually.)
So...
Sachs Duomatic: Rare, but apparently it's 112 mm OLD, and doesn't blow up like the modern kickback Sturmeys.
Sachs Automatic: Rare, but essentially an ancient 114 mm OLD version of the SRAM Automatix (1.36 high gear instead of 1.37, and more compact)
Sturmey-Archer S-RC3 or AWC: More common, current production, 116 mm OLD. Downside is added controls.
There may be other options (older Sturmey hubs, older Sachs 3-speeds, and the like), that I'm not aware of.
The Nexus 3 is 120 mm, the SRAM i-Motion 3 is 130.
Edit: And looks like I'd have to drill holes in the frame to internally route a shifter cable.
Edit 2: Sachs 515 is 115 mm OLD, it seems.
Edit 3: And the original Duomatic 101/102 is 110 mm.