Well I'm looking for a bit more speed. I've tried a 21 and 22t pinion but the motor gets too hot. So I put the 20t back on and the motor and esc remain prettly cool. I was told to try to gear down on the spur to gain the speed even tho it will bring more heat. Well since I'm not overheating now maybe I can get the speed I want without overheating with the 84..not sure that's why I was hoping to get schooled on gearing.. Thanks man