[sorenjan]

There are some that use Shimano Alfine, like the Priority Apollo and Shand Leveret, and others that use Rohloff like MiTech R-Gravel and Shand Cycles Stooshie Rohloff. They're still much rarer that derailleur bikes, though the latest innovation is using a rear derailleur and a 2 speed gear hub with the Classified Powershift.