I was thinking of gearing rather than belts,but think will have to wait till I have the motor simply because the ER25 chuck spindle is only 100mmin length and the motor is about 10" long,this could be a problem mounting the two together because as you pointed out the bearings need to be at the very ends of the shaft.

The motor doesn't have a shaft as such but a screwthread sticking out the motos body.