There were some bodges done for the Rohloffs, ie the twist grip on a piece of dowelling attached to the head tube or the lower part of the bar. Why you rarely see a Rohloff and drops
If you look @ old Moulton six speeds with drops I think they put the trigger on the top of the drops next to the stem.
They also used to put 3 speed triggers on the bottom of the bend of the drops-
None of them were satisfactory and I suspect you would have problems with tube and clamp diameters now
but those bar end shifter look right, and cheaper than STI...
There were some bodges done for the Rohloffs, ie the twist grip on a piece of dowelling attached to the head tube or the lower part of the bar. Why you rarely see a Rohloff and drops
If you look @ old Moulton six speeds with drops I think they put the trigger on the top of the drops next to the stem.
They also used to put 3 speed triggers on the bottom of the bend of the drops-
None of them were satisfactory and I suspect you would have problems with tube and clamp diameters now
but those bar end shifter look right, and cheaper than STI...