New 1x drivetrain – 10 or 11 speed?

I need a new drivetrain for a xc/race hardtail (its currently single speed).

Should I consider XT 10 speed with a wide range cassette (like sunrace), or an 40t expander which might be a bit cheaper, or just go for XT 11?

Can your current hub take a 10 sp cassette?
Vs £ of new 11 sp driver for your existing hub?

2nd hand 10sp shifter can be picked up easy enough.
As can a new XT 10 sp 11-36 cassette and chain of choice.
Superstar and others do a 40t expander for £25
If your rides are v hilly and you’re on a 29er then a 42t may be better.

The only thing I’d like being on 10 sp is a 10t on the cassette but am willing to go without.

Vs £ of new 11 sp driver for your existing hub?

Shimano MTB drivers work with both 10 and 11 speed Shimano cassettes. Only SRAM MTB 11 and road 11 need a driver swap.

OP: I’d go with XT 11, less faff.

an 40t expander which might be a bit cheaper,

Won’t be cheaper.

If you’re having to buy everything, just go 1×11, although you’ll probably be able to use your existing cranks.

If you’re having to buy everything, just go 1×11, although you’ll probably be able to use your existing cranks.

This.

Peruse the German sites, you can get XTM8000 mech, cassette, chain and shifter for around eu200.

If you need an expander it’s about as much to just go 11 speed (like for like with XT) and be future proofed. The Germans were cheapest when I got mine.

I figured it out as £159 for mech, 42t cassette and shifter from bike-discount and a 105 chain from Merlin for 11 speed versus £145 for 10 speed XT from bike-discount. If you get a 40t 11 speed cassette they work out the same price.

Rather than fiddling with an expander just get a sunrace 11-40/42 10 speed cassette?

I would go for 1×11 XT if you are replacing everything. No point going for 10 speed then bodging with an expander cog when a properly designed solution is available. 10 speed was great and I have it on 2 bikes and wont be changing it any time soon but the shifting on my 11 speed is much nicer.

You may find 10speed and standard 11-36 sufficient. It’s what I run with a 30T up front and I don’t find it limiting. By the time I’m spinning out it’s generally quicker to freewheel and unless you’re doing SDW etc the 30-36 will get up most things.

The main advantage is an XT 10sp 11-26 is quite a lot lighter than it’s 11speed twin.

You may find 10speed and standard 11-36 sufficient. It’s what I run with a 30T up front and I don’t find it limiting. By the time I’m spinning out it’s generally quicker to freewheel and unless you’re doing SDW etc the 30-36 will get up most things.

The main advantage is an XT 10sp 11-26 is quite a lot lighter than it’s 11speed twin.

That was my thinking a XT 10 with a praxxis 11-40 cassette would have the same range as 11s but it would be lighter (roughly the same weight as 11-36.