With the various choices of axle length for any sturmey archer hub is it just the axle, shell, nuts and toggle chain that differ, with all other internals being the same?
I think in some instances the shell is the same and the axle nuts and axle account for the OLD specification, but in other instances the shell is different.
I'm guessing there's always potential on the left side/non-drive side for changing proportions so it wouldn't make sense to have different driver/pinion etc specs. . . ?
Looking at centre-to-right flange specs across different hub ranges there doesn't seem to be one single approach to flange position. On the S-RF3 no matter the axle width/OLD the flange position remains the same (relative to center), whereas on other hubs it seems the flanges remain constant relative to the drive-side locknut. But this is to do with shell design and nothing to do with internals, I assume.