Converting 3x to 1x Drivetrain I have a new crankset (link) on the way as well as a chain guide/bash combo from OneUp. I am getting a 36T narrow-wide chainring also. 

The bike I'm working on has a SRAM 3x9 drivetrain with 11-34 cassette. What else, if anything, do I need to convert it to 1x9 (other than putting the new crankset on and removing the unnecessary front der &amp; shifter)? 

Is it correct that Shimano 11sp cassettes fit on 8/9/10sp freehub, so I could in theory change it to a 10sp or 11sp cassette? I'm not planning on doing that ATM but just in case...
General consensus is that a 'clutched' rear derailleur is also a key component to a good/successful 1x setup. These derailleurs provide a tighter 'pull' on the chain and help keep it from hopping off the chainring on rough terrain.

For cassette/freehub compatibility, read the discussion that occurred here: 
https://bicycles.stackexchange.com/a/28908/30533 ...


  Shimano/SRAM 11 speed cassettes are wider than 8/9/10 speed ones. So yes, you need a new, wider freehub body, unless your old one was not very old and used a spacer to fit a 10-speed cassette.