hot esc

[rfoxloon20]

Im new to the brushless motor/esc thing, I have a trf 201 with a tamiya tble02s and a atomik 8.5 4400 kv motor. Had it geared with the stock spur which I believe is 69 teeth and a 22 pinion the car went good and the esc was warm to the touch, so I went to a 24 pinion and it is peeling the tires off it fast and the esc was hottish. I was under the assumption that gearing up was less taxing on the motor, obviously thats not the case on this car. Would the esc be even cooler if I went down to a 20? Maybe I could keep it under control then or would the motor be working too hard low geared like that. The esc has a high temp shutoff so im not overly concered about frying it, just want to find the sweet spot for the motor and esc.
Im going to order a 4000 7.4 lipo this week as im currently using a 1500 7.2 nimh and with the 22 tooth I had about 6 or 7 minutes run time, the 24 got me about 3.
thank you for reading, appreciate any input.

[Coelacanth]

If a motor gets too hot, that's usually a sign that it's over-geared. ESC overheating can be caused by improper gearing (too much or too little) as well as too tight of a gear mesh between pinion & spur gears, too much drivetrain resistance (without motor in place, everything should roll smoothly) and also driving conditions (i.e. driving in high-traction surfaces or grass will have much more resistance to the electronics than asphalt or packed offroad surfaces). That's just a bare guideline.

[terry.sc]

Gearing up will put more load on the motor and ESC.

Lets say you have a 10 tooth pinion on the motor and the internal gearing means it take 10 rotations of the motor to turn the wheels once. If you replace the pinion with a much bigger 20 tooth pinion it would now take only 5 motor rotations to turn the wheels once. This means the motor now needs twice as much torque to move the car forwards as there is a much greater load on the motor.

Also the ESC will be getting hot because the 8.5T motor is on the limit of what the TBLE-02S can handle, if the motor is overgeared it will push it over the limit of what the ESC can handle. I wouldn't run less than a 10.5T on it.