In theory, with a single-speed bike, like the majority of modern hub gear bikes and virtually all Rohloff-equipped bikes, you can run a transmission set of the chainring, sprocket and chain into the ground until the first of them breaks, then replace them all at once. The benefit of this method is supposed to be that the components will all have worn together and thus fit together optimally for their state of wear until the end, the expectation being that this method would deliver the greatest possible mileage from the set and, as a bonus, avoid fitting a new chain to worn teeth, which will ensure that the new chain gets to only half the mileage of a chain fitted to new teeth or reversed gears.
"In theory" means I haven't tried it, among other reasons because the underlying assumption above is that all the components have roughly similar lifespans, which just isn't true on my bike, where the Surly stainless steel chainring will very likely have a service life in excess of a magnitude larger than the KMC X8 chains I use, and the Rohloff sprocket will have a lifespan at least 5x the chain life; in all of this the qualification is "in my zero maintenance paradigm, in which I run the chain for its entire life (to half-a-percent wear at which point, at about 4500km, I chuck it off at the Rohloff oil change) on the factory lube with nothing added, inside a Chainglider". Note also another assumption, that there is a whole link-and-a-bit chain adjustment length built into the bike, which isn't true of eccentric bottom bracket adjusters as fitted to Thorn bikes, or even on most bikes with track (slotted) frame ends at the rear of the bike, though Rohloff's own "slider" axle hangers (for which they'll give OEMs blueprints free of charge) have the "correct" length for all likely needs, including this one.
