After snapping my rear derailleur and running down my existing cassette and chain I’ve decided to take the plunge and convert to a 1×11 set up. Going to go with XT 11-42 cassette, XT shadow+ 11 speed mech and XT 11 sped shifter and chain. I’d like to use my existing crank arms from XT M780 triple and have picked out the Race Face single narrow/wide chain ring (32T). Will the crank arms fit the ring? Is this a good set up?

Yes they will and yes it is.

I’m running a superstar ring on m970 xtr cranks, xt mech, shifter and 11-42 cassette with a kmc chain – comes with a quick link unlike the shimano chains.

Had an issue running a 30t ring where the chain would catch on the 13t when in the 11t, doesn’t happen with the 34 I’m running now assuming it is due to the built in spacers on the 30t to clear the chainring tabs, shouldn’t be a problem with a 32t.

The only thing I did different on my recent 1×11 conversion was to use an XTR cassette rather than a XT. Quite a lot lighter and not too much more expensive.

How’s that not much more expensive for a XTR cassette, £135 vs £57 for the XT?

not too much more expensive.

Well over twice the price for XTR…

£124 from Wiggle – Ok far bit more expensive – senior moment!

Think I’ll stick with the XT at those prices.

Based in Brighton much of my riding involves the South Downs. In your opinion is an 11-42 cassette and a 32T ring suitable? Can anyone confirm the type of mech I will need. I’m thinking long cage (not medium). Thanks for all the comments so far.

What size wheels ? It makes a difference .

I’m thinking long cage (not medium).

What’s your reasoning behind this?

11-40 and 32 is ok for me on South Downs so imagine 11-42 is fine.

26 inch wheels.

Read somewhere long cage mech was best for 11-42 cassette??

Medium will be fine for 1x.

Personally I much prefer the sram, the xt weight of the cassette is obscene, take a look at gx.

Cheapest I can see the sram GX cassette for is £75.. Factor in the XD driver for another £54 assuming you are coming from a shimano freehub.
GX cassette 394g £75+£54=£129
XTR cassette 331g £125

Granted I don’t know the weight of the XD driver or shimano freehub..but at the above cost it makes sense to go with the XTR and save a bit of weight..simplicity and a fiver..