Thanks @Pottery @WindWarrior @TexanDad It is interesting that Wahoo and others supply a 1.8m spacer (at least per their website, I’ll measure mine tonight) but SRAM says 1.85mm. Hard to imagine that a .05mm makes a difference but seems odd that there is subtle difference.
Otherwise this is an easy swap and look forward to seeing how it allows more free spinning out on course.
Whatever I had measured roughly 1.87mm with my digital calipers. Close enough!
FWIW this BTD page
says 1.85mm spacer, but read the description and it states 1.8mm
Lol… I guess the tolerance isn’t that tight in reality.
Agree, but I think XD started with SRAM eagle (or maybe earlier), so it’s a bit of a legacy MTB thing. Yeah, they could have started making all hubs XD-R at some point along the way, it’s just hard to change stuff like that once it’s out there. If they switched MTB hubs to XD-R, it would still confuse folks because it would then be inconsistent in the MTB world.
Great to know this is an option. I have a Crux Pro on order. 
Nice bike! I have a wired Eagle GX build with same 44T chainring size. Do you find this chainring is ok over long term. I see so many bikes with 36T-38T chainrings that are useless for downhill speed in my view, plus 44T is a good workout uphills right?
I’m not gonna find any hills in North Texas that a 44 x 52 ratio can’t handle. Maybe way out west in big bend but that’s like a once a year trip at most.