Reasonable selection of gear ratio is very important. Improper gear ratio may cause damage. You can select the gear ratio according to the following points!
The operating temperature of the motor
The motor temperature should be lower than 100 degrees Celsius (212 degrees Fahrenheit) in operation. High temperature may cause the magnets to get
demagnetized, the coil to melt and short circuit, and the ESC to get damaged. A proper gearing ratio can effectively prevent the motor from overheating.
The principle of selecting gear ratio
To avoid the possible damage to ESC and motor caused by the overheating, please start with a small pinion/a big FDR and check the motor temperature regularly. If the motor and ESC temperature stays at a low level during the operation, you can change a larger pinion/a lower FDR and also check the motor temperature regularly to ensure that the new FDR is suitable for your vehicle, local weather and track condition. (Note: For the safety of electric devices, please check the ESC and motor temperature regularly.)