Sure someone must have asked this before but can’t find it on here.

Will a Shimano 10 speed XTR M985 crankset with single ring work with Shimano 11 speed cassette/gears etc? Any special chainring required?

Yes.

No.

Yes it’ll work. You need an 88bcd outer ring in 32t flavour. I think Wolfrace do one.

88 bcd? Don’t think mine takes that size it’s 104 (double running as a single).

M985 double is 88 BCD

My mistake I think it’s an M980

M980 (trail) is 104BCD. Any single chainring should fit

M985 (race) is 88 BCD. Good luck finding heaps, although there are a couple of company’s who do them.

Ah yes, sorry, in my being slightly clever I should have pointed out that the M985 Race, as Daffy says, needs an 88mm BCD ring.

I’ve got a very nice custom titanium one from before narrow wide times. Don’t want to throw it away.

Can you see your bolt heads? If so, it’s an M985. If not then it’s an M980. Inner ring being 28t or bigger is M985 too.

Yes
I run this same thing
M985 crank with 34t woof tooth ring

Out of interest, any idea if an M985 double chainset will play nice with an 11 speed chain and cassette?…

Yeah, it’ll be fine. In double configuration I presume you mean?