Brushless motors for RC models are commonly used for electric longboard project, mine is a RC Car motor. There are now motors that are specifically created for electric skateboards, with a sealed enclosure or custom form f
These motors are usually categ
orized by their KV rating. The KV rating refers to the rpm constant of a motor – the number of revolutions per minute that the motor will turn when 1V (one Volt) is applied with no load attached to the motor. It is related to the power out from a motor, or more usefully the torque level of a motor. In summary, a low KV motor will produce higher torque, a higher KV motor will produce higher speed but less torque.
Suitable motors for electric skateboards obviously need to have high torque (between 150kv and 300kv).
Note that motors can be sensored or sensorless. Sensored gives a smoother startup, but a lower top speed. The Electric Speed Controller can use sensors at startup and disable them at a certain RPM. The sensors measure the voltage based on the position of the stator with respect to the magnets, so basically it detects the position of the magnets and the Electric Speed Controller (if compatible) is able to more accurately command the motor to the correct RPM.