I intend to change the bash and 2×9 to bash and 2×10 on my 27.5″ wheeled hardtail. Will the two inner rings on a 3×10, say 30 and 22 be a workable combo with an 11-34 cassette, or would it make more sense to do away with the bashguard and go pure 2×10 with 36 and 22.
Also why do bashguards not seem to be used so much nowadays?

If you’re using a triple crank as your base, the only reasons not to go double and bash are weight and cosmetic. The rings from a triple will work with one caveat- the middle ring you’ll be using as your outer is ramped and pinned for derailing up as well as down which gives slightly worse potential for chaindrop. A bash would help with this.

A true 2×10 crank has a different offset and results in slightly better chainline, but also means you want a true 2x front mech and shifter for really perfect shifting. A generic triple with the limit wound down will work but never quite as perfectly.

Good question. I am no riding god I admit and sure used my bash guard in fort William this summer.

Just from my own experience with a 2×10, when descending, I’m often in the larger of the 2 chainrings. In general, you’re less likely to damage any chainring teeth when there’s a chain round it. If this wasn’t the case, you’d see more people with 1×11 + bash.

You are right though, bash-rings have slightly gone out of fashion. But chainrings have got smaller, and wheesls bigger, so perhaps people aren’t trashing their chainset against rocks as much these days (or I’m just lucky !)

In general, you’re less likely to damage any chainring teeth when there’s a chain round it.

this is the reason you cannot really bash it with a chain on it
that said my bash – left on because i did not have the short bolts to remove- has never dropped the chain using a ramped normal middle from a 3×9 set up

As for gearing you know your power not me so pick what best suits you for the terrain you ride. I cannot see why you need a 30 and a 22 as my big bike is a 30 only and with a 42 rear gives same gearing as, IIRC, a 22 and a 34 rear

Single and an cassette extender was what i went for YMMV

You can get lighter weight alternatives now – bash guards that mount to the ISCG tabs for example.

And most of the bashrings are cut away to only work when pedals are level, which is when you tend to hit stuff with the ring rather than the crank.

But yeah nothing wrong with a bash ring, I took mine off the HT just because I had the confidence I’m a lot less likely to bash stuff (and it’s unnecessary weight if not needed), I found it great for getting the confidence to try stuff where it might hit.

Although the chainring with a chain is less vulnerable, my bro did manage to bend a ring hitting an obstacle recently (with the chain on that ring) so it’s not impossible to damage it – pretty sure a bash would’ve been fine in that situation.

In terms of what rings to use, it depends. 32×11 top should be fine for 99% of people 99% of the time, particularly off road. 36×11 might be useful occasionally but means you have less overlap between big ring and granny, which can be quite nice to have if you’re not sure which ring you need for that section of trail, say.

So fit a bash, and just use the middle ring on there for now, if you find you need something bigger then you’ll have to fit something bigger.