Installing XX1 for cheap on an old 26" bike- cheaper option than the XX1 crank/ring?
 

I've installed XX1 on modern bikes- 142x12 27.5/29ers with complete XX1 groups and DT or Stan's wheels back when XX1 was released. It's been a while since those builds, and new bike money isn't really in my pocket, though I have a 26" hardtail mountain bike (aluminum frame, threaded BB) that needs a drivetrain, and I like 1x11. Before I give up and just do 1x10 like usual, I'd like to rule this idea in or out.

-The shifter, RD, cassette and chain are a given. No way to cheap out on those.
-I can get cheap XD hubs on ebay, and I have rims and spokes.

What can I do about the crank/chainring? I have Shimano and Raceface 3x cranks, but I don't know much about aftermarket rings/adaptation, chainline, etc. I've heard about other companies making narrow/wide rings- I'm unclear if anyone makes narrow/wide rings to adapt 2x/3x cranks to XX1, or are they just making their own XX1 rings?

Is anyone running XX1 on an older bike?

The aftermarket wide narrow rings are in common sizes so most double or triple cranks should work. Personally I like the ones from endless bike because the lady who owns it is awesome.

The cheap way is to forget about it and run a 1x10 and a 30 tooth narrow wide chain ring up and/or swap in a 40 or 42 tooth add on ring from one of the many companies making them to your 10 speed cassette. I just put a 30 tooth raceface chainring on one of my bikes to turn it into a 1x9.

If you have a 104 bcd crank, you can use any aftermarket (Race Face, Wolf Tooth, Absolute Black, etc) narrow wide ring...and they will work with the XX1 chain.