3x9 conversion 1x10/11/12

Good news is no wheel/hub change required. 10,11 and 12 MTB can all use the HG freehub you have already (if you buy the correct cassette, i.e. not an XD or microspline one). You can reuse your existing crank, just fit a narrow wide chainring in place of the middle ring (check the ring BCD but at that age is likely to be 104BCD) and remove the other two.

Required parts;

Shifter
Rear mech
Cassette
Chain
Narrow wide ring

I'd suggest 10 or 11 speed deore with a 11-42 or 11-46 cassette.

Second bit of good news, no new tools required.

Assuming it's a Shimano 9 speed cassette, 10 or 11 speed won't need a new rear hub. There are ways round 12 speed needing a new hub too by using sunrace etc cassettes.

You shouldn't need a chain guide for 1x drivetrains - it might be sensible if you're doing big enduro/downhill descents on them, if you get a narrow wide chainring that will give you great chain retention without a chain guide - you'll likely be able to find one that would fit on the middle position of your existing cranks.

So if you get a new shifter, derailleur, cassette, chain and chainring to replace your 3x9 stuff and keep your existing cranks it should just be a set of Allen keys, a chain tool and some snips for tools. If you change up the cranks then the only addition is one of the plastic preload adjusters.

You can still get 3x9 stuff but it'll be alivio/acera level from Shimano so a step down from your XT.

Broadly as above, but:

1) You'll also need either new single chainring bolts to mount just one chainring to the centre position, or (cheaper and better chainline) 4x2mm spacers to go between the new chainring and crank tabs, using the original bolts. Or bung some washers where the outer chainring was...

2) Personally I'd get an 11 speed 11-50/51 Deore/Sunrace cassette paired with whatever chainring gives you the lowest gear you want, getting closer to the range you had with 3x9 than above. I'd also get a 12 speed mech that'll arguably work better with a wide range cassette like that (11 & 12 cross compatible).

Do you think it's worth the upgrade to 10/11/12sp?

What would the benefits be? it's primarily a tarmac/commuting bike.

Depends if there is anything in your existing set up that is salvageable. If both the mech and the cassette need changing then might as well go 1x. Main benefit is getting rid of the front mech. I did it 15 years ago and never looked back.

it’s primarily a tarmac/commuting bike

Maybe wait to see what real world prices are like for the shimano cues groups - they're pretty much aimed at that segment of the market.

Do you think it’s worth the upgrade to 10/11/12sp?

Not for commuting. I would buy a cheap 11-28 cassette and try to find some 26-36-48 chainrings. Deore level used to do that, with steel rings on the two inner ones.

For commuting I went 1x9. Range of gears is fine and it enabled me to keep using my old 9 speed stuff retired from my MTB. See below.

On my MTB I always said I couldn’t see the point of 1 x but converted to 1x10.

Main benefit was a clutch rear mech and getting rid of the front mech on my Maverick which was always awkward to get just right.

May be even cheaper to buy a new chainset with removeablle rings if you want to keep the XT cranks.
I use a old triple converted to double in two forms. Mixed surface commuter simple has the outer ing taken off and mech stop would in. Now have a 30/42 with a 11-32 on the back. Climbs anything. A rougher mixed surface bike has a MTB triple with the 42 moved to the middle and a 28 as an inner. Same cassette. No money has been used and the double is more useable on the road with less in the way of nasty gaps.

Pros - 1x No front mech clutter

Neg - 1x The rear mech hangs a lot lower. It's the only time I've ripped a rear mech off, riding through woodland.

I wouldn’t personally rush into 1x for commuting / road use. Whilst it’s nice for off-road where you can forget about the front mech I use the full spread of gears on my road bike which is 2x11. 34/50 chainrings and 11-32 cassette.

A question here is do you currently use all 3 chainrings with the full spread of cassette range with each one? You need to workout if you actually need the full 3x range.

If you can fit within a 1x range then probably your cheapest option is a wide range deore or sunrace 11 speed cassette with a deore 11 speed clutch mech (think it’s the 5100), bang on any decent 11 speed chain and a NW ring in the middle chainring position on your existing triple. Any 11 speed Shimano shifter you can find on offer will do the job.

For road 2x11 gives you closer stacked gears and a better chain line more of the time - but you’d have to get new cranks for that which would cost more money.

I wouldn’t personally rush into 1x for commuting / road use.

Depends entirely on the commute, surely? My commuter is 1x7, with a 46T at the front, in top gear I can get to 15-17mph without sweating along a mostly flat shared path and get to work in 20 mins. Perfect. If I had a ginormous hill in the middle of it, I'd probs be on a different set-up.

This seems to me perfect Shimano CUES territory. Fit a system that you know you can upgrade easily in the future that's built for longevity.

My commuter is running 3 x 7 - mix of 8 speed XT and LX 7 speed shifters. 12x25 cassette as it gives me decent close ratio on the flat, but I've still got the granny rings for some off road climbs I have on my route. Running semi-slick tyres.

XT hubs, XT Mech and canti's, LX crank and shifters with a sunrace or microshift 8 speed cassette with one missing sprocket to make it 7 speed.

Funny how 3×9 seems to be considered ‘retro’ now…

With the benefit of hindsight, clinging on to 3X systems (or more specifically; front mechs) for as long as they did , it does fell like the 'Bike Industry' missed out on years of development. Although, when they first arrived the 29er bikes were shit, they development curve they forced has made the industry catch up with itself very rapidly which I recognise has meant that many folks feel left behind. But - and perhaps more importantly, we're largely in a better place

The problem with 1x is that those of us who are used to closer gear ranges, find the jump too much - OK on 'proper' off road, but gravel/paths/canals etc, the closer gears keep you in a good spinning range, rather than too fast or too slow. Closer ranges are better for a flatter commute, with the option to drop to a low gear if needed. Ideally you'd have a suitable bike for 'your' commuting, and something else for fun.

I don't disagree, but not everyone finds jumps in gears problematic, for some the subtle changes aren't noticeable or are just "a minute" variation of the gear I was just in...Horses for courses. But given that this is a forum for mountain bikes

29ers forced...

Designers to confront wheel rigidity, which forced them to settle on wider hubs which forced them to examine and re-design the bottom bracket area, which forced them to think about gearing, which along with wide hubs allowed more space for larger cassettes which meant that the front mech could be discarded which freed up all sorts of space for properly function suspension systems which in turn freed up designers to move away from a shape inherited from road bikes...

1x is a result of revolution, and while it doesn't suit every one, I don't think anyone (outside of a few romantics and nostalgists) want to go back to what we had before. Or if they do, they're finding a home on gravel bikes.

"fell like the ‘Bike Industry’ missed out on years of development" or is it found another way of selling more toys which s their job?
"and perhaps more importantly, we’re largely in a better place! Really? We have ditched the simplets, most fool proof moving bit of a bike. And gained something way more complex and vulnerable that it's forerunner.
Bit like modernc cars I guess. Mostly pointless and imposed.
Ah well , each to their own. Makes STW interesting doesn't it?

Another 1*9 rider here. On my city/local rides bike. Spins out around 24mph which is fine and gets me up anything I need to ride up.

A 38t single ring and 11-34 cassette. No clutch mech. I stuck one of those dogtooth devices to stop the chain falling inwards but I don't know if it was needed.

Not a narrow wide chainring just a cheap single ring crankset.

https://www.sjscycles.co.uk/chainsets/33-mwave-alloy-single-chainset-with-170-mm-cranks/

I've wondered about this myself - my 3x9 XT drivetrain works absolutely fine and I'm in no rush to change, but I'll idly consider whether it's worth going 1x.

Tbh I'm not sure - is there any point to switching to 2x instead (2x10, say)? It still gives the range and number of useable gears, right?

On my current 3x9 I can't ever remember using anything other than the big chainring up font.

In reality I've got a 3x9, but I'm probably using it like a 1x4 or a 1x5 at most.

is there any point to switching to 2x instead (2×10, say)?

I run most of my bikes as 2x with either 26-36 or 28-38 rings and an 11-36 cassette. That gives enough top end to cruise on road, but a bail out gear for off road. I find a 36x11 top gear is tolerable for commuting on a hybrid mountain bike with 29" wheels, but 32x11 just annoys me with constantly feeling like I'm spinning out on the slightest descent. If you're never going off road, probably a 32-42 setup would be all you need for commuting. But, if you already have a triple, you might as well just keep the granny gear on there

It was a bit disappointing to see the newer Voodoo Marasa since getting mine in '20 had ditched the 3x9, these days especially I really appreciate all those low gear inch options, having piled on the pounds and lost my summer '22 legs.

There were some decent sale priced 9-speed drivetrain bits at Merlin just recently, including a replacement 12-36 cassette I've now got in the "spares box."

Shimano Deore 1x11 with wide-range cassette (51t) and matching derailleur including shifter and chainset can be had for £190.

It's what I MTB with and my friends are the same.

3X on all my bikes except the gravel one. Won't be changing any of them. Uphill or laden=granny, most terrain=middle, downhill or tailwind=big. No clutch, no N/W chainring, no eye watering prices. Close gears over a wide range and bits are cheap. Happy.

I went Sram 1x12 on my 2011 Orange 5 (it was 3 x 9) and found it a revelation.

The conversion was relatively easy and works with ease.

You will never look back.

I've just built up my Mk1 Cotic Soul to make up for the lack of effort I'm expending on the eBike. Currently it's singlespeed and I'm thinking that might not be a long term thing.
I'm tempted by the all-in price for some NX groupsets. My question is whether the crankset would be compatible with the 68mm threaded bottom bracket (yes I know I'd need a DUB BB) and a non-boost chainline. Or do I buy the groupset, sell the crank and get a narrow wide chainring for my old XT crank.
One of the benefits of this is that my eBike is NX, so I'll need a cassette before too long so I might as well do that now and put the old cassette and chain on the Cotic and the new cassette and a GX chain on the ebike.