I am going to be running the RR on the rear and the NN on the front both in UST 2.1 on a lightweight hardtail with Stans sealant.

Good combination for most things? Where will this combination not be any good?

Will be running a different bike with Bonty Mud Xs when it gets uber gloopy so mud is not an issue.

Any advice appreciated. 🙂

Personally I would run NN both ends – it will look like an RR after a few weeks anyhow

got NN UST both ends on the klein

seem very capable in most conditions

I run 2.25 UST NNs F & R and they roll really well. UST sidewalls are really thick, so you can run stupid low pressures if you want, plus you won't get slashed sidewalls.

NN both ends. Cant fault them really. RR for hard pack trail/dry summer/Alp or Spain rock type trails. NN cope better with softer wetter ground. IMO of course…. but at £45 each at the LBS its an expensive job. Chain Reaction or Wiggle may be better…

I'm running (standard) NNs front and rear, tubeless on 355s. They seem to be fine so far.

Bike24 or HiBike for Nobby Nics. Much cheaper than the UK even after adding postage.

2.25's here, got 2 years of part time use out of them in all conditions, best tyres ive ever used.

Totally useless on a wet Lakes ride round Burnmoor Tarn a few weeks back. Racing Ralphs are exactly that – for racing.