One of the guys I’m riding with needs a new rear mech, casette and chain.
I was wondering if the new XT 11 speed stuff will work with his current 10 speed front mech/shifter?
He is thinking of going 1x at some point..

no

no

care to elaborate on why it wont work? I was thinking of doing this as well, but I couldnt see any reason why it wouldnt.

9 speed front mechs work with 10 speed.. All it is is a cage that brutally drags the chain across the chainrings. Horrible things

The only issue might be that said cage is not wide enough for the variation in chainline accross 11 gears but as the cassette fits on a normal freehub there shouldn’t be an issue. plus you shouldn’t be using big ring with small sprocket and vice versa as half your gears will overlap anyway

oh i didn’t read it all, ha, yeah it’ll be fine, limits setting might be tricky as the degree of chain movement is increased, but if hes goes 11sp, he wont need a front mech