[BrianG]

I wonder if we should add a new "rule" to the above list:

hot motor, hot ESC, and hot batteries = overgeared

These golden rules were defined back when cells would drop voltage a lot more under load. When an overgeared system drew too much current, the battery voltage would drop substantially, which means the voltage getting to the motor was much less. And since power is defined by V X A, heat was much less. Since ESC heat is a function of mostly current, it doesn't matter what the voltage is (to a point). The result is the battery and ESC would get hot from lots of current, but the motor would stay relatively cool because it's not seeing both high current AND voltage (just high current).

Today's batteries hold their voltage much better under heavy current draw. An overgeared system will still cause the ESC to heat up about the same (because ESC heat is a function of mostly current), but since the battery voltage does not drop as much, the motor is seeing much more voltage (and therefore power). As a result, the motor is getting hot too.