Not had any issues with my narrow wide ring at all, never dropped a chain until today when (typically in a race) it came off twice.

Is it simply that it’s got worn enough that suddenly the tolerances aren’t good enough to retain the chain?

It does look pretty worn, but before I splash out on a new ring, is there anything else that might be causing it to drop?

Chain is pretty new. Rear derailleur looks straight and has no issues with rear shifting (although I can’t see that a wonky rear mech would affect chain retention anyway). Clutch tension feels ok (new xt 11 speed).

Just worn, wide bit can’t do it’s job.

What ring and chain?

Race face narrow wide cinch, kmc chain. Been riding it for six months with no issues (changed chain in that time but always kmc)

My drops were with KMC chains, when a small amount of mud was introduced. Absolute Black reckon there is something a touch off in the spec that is only noticeable on a NW ring but I’m not sure how much truth there is in that or if the same would be true with a RF ring. Anyway, XX1 chain solved things even on the same worn chain ring for me.

It’s worn out. As a side note my local bike shop said race face chainrings were known for wearing quicker . Which I thought was probably spherical and in the plural but hey ho.