[BRAVESaj25bd8]

Well it really depends on how you lift them. Let's say you are lifting two robots at maximum weight straight in the air with one winch-type mechanism. I think with batteries and bumpers, that would end up to be about 300 pounds. So you take the radius of the output shaft of the winch which the cable is wrapped around and multiply it by the weight. This will give you the torque necessary to raise the two robots. (do a quick unit check and make sure you get either in-lbs, ft-lbs, newton-meters, or some other force unit multiplied by a distance unit).

That was for a very specific way of lifting the robots. Like I said, it depends how you want to lift them. You're on the right track though thinking torque. Try a wikipedia search about gear ratios. That should help also. Good luck!