For the 2 hub motors I installed on donor bikes it made sense to have the lead out of the axle, be it front or rear, to exit upwards to the forks or seat stays, avoiding a downward loop which, on an MTB, might snag in the woods. It did mean a small area open to the elements at the exit from the rubber wheel nut cover but this can be sprayed with water repellent or wrapped with self annealing tape. On balance I'd rather leave open to evaporate any moisture build up during cold nights in the bike shed! I have since noticed that kit instructions say " mount cable exit downwards" I agree this would give a little more slack, enabling the wheel to be taken off without having to snip any cable ties off. Which way do you guys do? Up or Down!