Is a shifting transmission really necessary?

[Ian Mackenzie]

There's one more subtle issue that I think is worth pointing out. Say you're designing a robot for Zone Zeal in 2002, and you want to make a ball pickup robot that tows the goal around behind it. Assume that you can make a robot with a 1-speed gearbox that goes 10 feet per second and can slip its wheels just before stalling, and that your driver is good enough that uncontrollability is not an issue.

From most of the posts above, this would seem to be an ideal drive system - but I would argue that there is still an advantage to having a shifter. Say your wheels slip at 90% of stall torque, and you can pull a goal at 80% of stall torque. Yes, you can pull the goal, but at that point you're running too close to stall to get max power output - if you geared down slightly, you could pull the goals around a lot faster. It won't help you push another robot (traction is still the limiting factor) and it won't help you get to the goals faster, but if you're towing a goal around for a large part of the match, it could still be very useful.