What do you use for a chain tensioner? Will the Rohloff one take up enough chain slack or did you leave the derailleur on?
Yes, we use the Rohloff chain tensioner, it is able to take up the chain slack for our case were the difference between the two chainrings is relatively small: 50t-38t = 12t.
I think it will work in most cases because small chainrings aren't allowed due to the torque limitation of the Rohloff. For instance, 38 front - 16 rear (the standard Rohloff rear ring) isn't allowed on a tandem, to keep the 38t front we had to go to a 15t rear. So you cannot use a smaller ring than 38t (unless you go to the 13t rear, but then you must also reduce the big ring size), on the other end, a bigger ring that 50t isn't really usable with a 26" wheel, so I think that the teeth difference we have is about the maximum usable and it is manageable for the Rohloff tensioner.
