[captain harlock]

Well, with brushless you can always gear higher, but you can only do that if you are mostly bashing and not racing. Once you notice that the esc is thermalling( does not work or deliver power) you must try things like cooling fans or lower gear ratios to keep the esc and motor in a moderate temp or slightly lower than -very hot- this way you will keep the setup safe and far from wrekage. BTW, the gear ratio that I gave you is a suggestion, but not a recommendation. I'm currently using 9:1 in my T4 with the 9918 and Lehner 1920/8 motor and 11 cells. My gear ratio should be gone a little lower, however.