[krankie]

I bought a surly KM a couple of months ago and bought the complete bike because it was a good deal and due to money issues I had that finance about 300 cause I was a bit short at the time. I wasn't real excited about some of the drivetrain but I figured I could switch it out later. I want to start with 29er wheels Shimano drivetrain. I was going to do the 29er wheels first and get a 11-50 cassette.

Question 1- can I run Shimano cassette and derailleur with the NX chainring for now?

Question 2- which Shimano derailleur will work with a 50 tooth?

Question 3- are spank oozy trail 350 29er wheels too wide for the KM?

 

[mr_manny]

You can keep the NX chainring.

If your Cassette is 11spd, you can keep that too.
You can run a Shimano derailleur with any Cassette, as long as they are the same speeds.
The Shimano SLX CS-M7000-11 rear derailleur is good to 46tooth.

Sorry, no info on spank oozy.

 

[HerrKaLeu]

None of the 11-speed RD are officially rated to 50. But the SLx and XT "should" work. They are officially rated up to 46T (your NX is only rated to 42T, but many use it with 46T).

You likely need a new chain to accommodate the larger cassette, but any 11-speed chain will work regardless of manufacturer. Same for the crank and chainring.

I recommend the XT shifter since it has instant release and double-upshift, which is good for MTB and fast speed changes. It will work with either SLX or XT RD.

However, if your NX works, it is fine enough. My guess NX is a few fractions below SLX. I never would consciously buy NX, but I'd just use it till it fails. My bike actually started with NX-11, and the shifter started making problems. That's when I upgraded to XT and never looked back.