So if the new ‘trail’ double chainsets from Shimano (XT, SLX) use the same bolt circle diameter as older Shimano chainsets, is it possible to just buy a pair of the chainrings to fit an older set of XT cranks and convert it to a double this way? (the model preceding the latest version)

I’d like to go 26/38, or even 26/36.

Anything to stop me?

I don’t think so, it’s what I’ve done and doubtless countless other people. You lose some bigger gear ratios, so anything involving longs flat bits of road get very spinny. But then if you’re doing lots of long flat road sections you should perhaps have bought a road bike in the first place.

And having 26t as the granny ring rather than 22t means you’ll need to be a bit fitter, and eat fewer pies, to get up really steep hills. Or get off and walk.

Went 2×10 with my XT 36/26

Bought the rings from someone on here and swapped with my 3×10

To get good shifting though you’ll need a 2×10 front mech (my 3×10 was horrific)

Small point to concider, some bikes won’t take that gearing, for example an orange 5 won’t take 26/38 chainrings.

Interesting. 24/36 works fine on mine.

Oranges official line… All 34 tooth work on all 5’s, some 36’s on some 5’s and no 38’s on any… Chain hits the weld when you shift up…

I’m running 22/36 2×9,and bash,with no problems,using old 3×9 front mech and shifter.

Its for a Zesty, I’m currently running 1×10 with the lowest gear being 34 chainring and 36 at the back. Some of this year’s Zesty’s run 2×10, so I don’t think there should be any problems.

Its fine for the UK, but I’m taking it abroad later in the year and if there are longer climbs I think I might want a bit lower gearing.