[jee7s]

Assuming you are in complaince with the rules (it's hard to not be given inspections) you should only have 2 CIM motors if you are only using 2 speed controllers. Each speed controller is protected by (at most) a 40A breaker. You can't drive a (single) motor with more than one victor under the rules (this also presents some coordination problems), and the victors can handle more than the 40 A (or so) that the breakers blow at.

Keep in mind that using two CIMs as drive motors gives you half the power of using 4 CIMs. This presents a possible solution, but it is too much weight given your margin.

Since you are only using two CIM motors, you have a limit to the force they produce as well. This depends on the reduction, but if the motors are loaded too much, they will draw excess current, and thus blow the breaker.

If these problems occur late in matches, look for something heating up or binding which would present mechanical resistance. Also, look for ways to eliminate friction within the drivetrain.

However, I would suggest you see if it is merely the time of the match that coincides with the breaker blowing. Consider what the robot was doing at the time. If it was pushing into a robot (or a wall) and you have high traction wheels, this would easily cause a breaker to blow.

EDIT: Almost forgot...

If a victor overheats, its internal resistance increases. However, increased resistance would cause less current draw. If the victor was overheating, you'd have a wonderful burnt plastic smell in the vacinity of your robot. Also, you would see decreased power at the motor without the breakers tripping. If it were to overheat too much, you'll melt the transistor packages, then cause all sorts of thermal effects that would alter the doping of each transistor, rendering it unusable. (but you'd probably stop before this when you saw the smoke and (potentially) fire.)

Part of what the rules do is prevent this. FIRST knows that a properly cooled victor handling 40 A, as expected in a match, would most likely not overheat. Safety is built into the rules