some gearboxes have a small extra grove at the bottom that allows the wires to pass through without hassle. look at this item:
http://www.airsoftgi.com/product/Lan...gs-Blue-17752/
if you look closely there is a openning at the bottom that allows for the wire to be looser which protects its against such damage. If you have a steady hand and a dremel drill you can make this mod yourself.