Recently upgraded to a 26/38 double, but the 26 inner is a bit tall for my usual spinny style, particularly for longer rides.

Can i swap for a 24T inner and keep the 38T outer (will the derailleur handle the 14T jump) or do I also need a 36T outer.

Or should i just MTFU?

MTFU, I’m usualy a spinner but cope well enough ona 32t single even in the Lakes. The trick is to ride fast enough that the cadence is more ‘normal’ and just block out the pain.

26-36 is an 18″ bottom gear! For each pedal revolution you’re moving less than 2x the diameter of the chainset! That’s more mechanical advantage than walking!

when you’re used to 22:32 or even 22:34 on a 3×9, 26:36 is still 5-10% harder.

Most of the time I’d be using 24 and further down the block of course, just like having the bail out option if needed.

There is a 24/38 combination in current XT double chainsets so if you have a current double XT front mech then yes, it will all work lovely. But you don’t say what mech you have…

Yes – should be no issues with 24/38. You may have to change while pedaling gently rather than grunting on the pedals.

It’s an SLX dedicated double front (M665)

Capacity on an SLX double front mech is 14T so you will be fine.