I’ve just bought a new 10 speed shimano XT groupset, but the mounting for the front mech is different…. Do you think my existing 9 speed front mech will work????

I reckon yes, pretty well if not perfectly – esp if you keep the existing shifter (no idea if the pull has changed on front mechs too)

Or I bet you can buy adaptors somewhere (is it direct fit to bosses on the frame ?)

(somebody who actually knows needs to email all answers to stw and get a sticky thread made for this)

Edit … you KNOW the mighty sheldon would have had this all posted up by now 🙁

or just sell/swap the mech.