I swapped the stock 2X10 XT out on my Trek Fuel EX 9.8 27.5 for Shimano 1X11 using the XT 11-42 cassette, XT derailleur, Shimano 11 speed chain and chose an XTR 11 speed shifter. I wanted to keep my 785 2X cranks if I could get them to work. I chose a Oneup 34T narrow wide mounted to the 104 BCD. I chose the Oneup because it came with 2mm shims to help with chainline on the 2X cranks.

Install was a breeze and after tuning the rear derailleur and sizing the chain everything worked perfectly in the stand. Today was my first opportunity to get it out on the trail and I couldn't be happier. Everything worked perfectly, shifting was quick, quiet and smooth, the XTR shifter is very nice and noticeably smoother and requiring less effort than the previous XT shifter. I had absolutely no chainline issues and pedaling was equally smooth from 11 all the way to 42.

Pics when I get things cleaned up!