On a related note to Rich' post -
Does anyone know the cable pull of the SA S3X shifter versus the SA 5 speed bar-end shifter?
I have a plan to make my S3X shift with a defined neutral position. Yes I understand at least 2 reasons why this might be a VERY BAD idea. (the position would be very narrow, requiring extremely careful adjustment etc, and failure of neutral could break the hub and attempt to break my legs - and if this neutral position is used for a bichain granny gear, there will be forces on the bike that might well move the shift cable position enough to de-neutral it)