New Chain.

[KDean]

I've just found a brand new  Sram XG1 12-speed   chain I had it as a spare for my Ribble .
Can I use it on my Nomad  Rohloff ?

[JohnR]

A 12 speed chain is probably too narrow to sit properly on the chainring and sprocket (I've never tried). That 12 speed chain will buy you several KMC Z1 chains.

[mickeg]

Agree with JohnR, if you can sell that chain, buy some cheap ones with the cash.

I recall reading at one time that Sram 12 speed chains can't be measured for chain elongation (or stretch) with some chain checkers because they have a different roller diameter than other chains. 

I have no clue if your chain has a different roller size or not, but if it does, I would not try it on a Rohloff sprocket.