Image from back in the day
I'm not sure if I can be much help to the cause but our team ran tank track back in the day, though now we are know by those who visit our pit for drum wheels.
Recently two of us attempted to resurrect this robot and learned a little about how the treads worked. It was tensioned with a worm gear, and before the old gear boxes gave way seemed to maneuver fairly well with the tension on the looser side of tight. It wreaked havoc on the breakers though you could year them popping clear across the shop when the tension was too great and it tried to draw more current.