[Closed] single chainset to replace this.

Don't change gears on the front??

Are you replacing the existing chainset because it's worn, or for aesthetics?

Are you replacing the existing chainset because it’s worn, or for aesthetics?

it is worn beyond use, and I cant find a replacement ring that will sit on the cranks correctly.

But that one and flog yours

...or any other Shimano road chainset and just use the inner 34T ring (you can get blanking bolts for the outer - AbsoluteBlack I think). Hard to find a road chainset with a single 34T.
You could get an AbsoluteBlack replacement ring, but it's probably cost about the same as a crank.

Is it not 110BCD, 4-arm, Asymetric like most recent shimano Road cranks?

If so Superstar do 34t up to 46t N/W rings that should suit, worth keeping the chainset and giving that a whirl?

and I cant find a replacement ring that will sit on the cranks correctly.

Where have you looked? You want a NW ring or just a replacement?

The Claris 34t inner ring is in stock at both SJS cycles and bikester for about a tenner

It's also the same 4-bolt asymmetric pattern as other Shimano road cranks, and various levels Claris/Sora/Tiagra/105 etc. are readily available. Rings from other manufacturers should not be hard to find either.

Looks like the R2000 has integrated nuts on the 50t outer chainring, so you would need to buy a new 34t along with some shorter nuts (as they are normally long enough to pass trough two chainrings). The nuts are the ring-shaped things in this item (although this one gets mixed reviews): https://www.sjscycles.co.uk/chainsets/single-chainset-chainring-bolts-pack-of-5/

Other people have already provided links to some rings (narrow-wide and regular).

https://www.sjscycles.co.uk/chainrings/shimano-claris-fcr2000-110mm-bcd-4-arm-inner-chainring-34tnb/

I'd simply stick a ten quid ring on it and keep using it without changing into the 50T. But I am a tight bugger.