I am close to pushing the button on a 29er frame and would like to set it up a 1×10. The frame does not have chain guide mounts butI have an old 3×10 groupset kicking about with a clutch mech.
Can I just lose a couple of rings on the chainset and trust the clutch to do its thing or do I need to go down the thick-thin route?

Actually, just found the chainreaction 1×10 bundle which looks good value and would mean no need for a bodge.

@bubs.

I’ve just converted my wifes MTB from 1×10 back to 2×10 so I was going to advertise next week OneUp 42t & 16t sprockets & RAD cage for the clutch rear mech.
You’ll need a 11-36t cassette. Its simple to set-up, full details on the OneUp website.
Also I have an Absolute Black Oval 34t thick/thin chainring one ride old.

Email in profile.

All you’ll need is a clutch mech and a nw ring and maybe bolt washers or short chainring bolts. Use your existing cassette and chain.

I’ve got 1×10 on both my regular bikes

1 is done properly with N/W ring and clutch mech.
The other is a normal singlespeed chainring and normal mech.

No issues with chain retention on either. I’m not arguing the N/W and clutch don’t help, but on a new-ish drivetrain normal bits work fine. Equally I’ve been running 1x drivechains since 8speed was the default, it was always rare to drop the chain more than once or twice a ride (although, invariably at a good bit!).

If I were you I’d fit a N/W chainring if you already have a clutch and dont already have a SS chainring, a geared chainring is designed to drop the chain not keep it.

Deore clutch mech and cassette, On one ringmaster fitted to an old pair of hone cranks, Zee shifter does OK for me…

CRC weren’t doing their bundles when I bunged my 1×10 setup together, they are pretty good VFM by the looks of it.

If you’re wanting to go the expander cog route I’d get a praxis cassette… £90 and you get a 322g cassette and no need to buy things separately.