Originally Posted by
scarlson
Contemporary examples include Rohloff and NuVinci.
I have a twin-cable Le Cyclo rear derailleur on my Jack Taylor. It is uniquely finicky to set up, but works much better than I thought it was going to, when I was going through rebuilding it. Granted that's in a stand. The real world may have other things to say.
You mentioning Rohloff reminded me of the Pinion Gear Box and made me wonder if it's a dual cable system. It is indeed. Not sure if it's pull-pull.
https://pinion.eu/en/accessories-2018/#module-id-11