Is it better to have a brush or a brushless motor for an electric bicycle? What is the difference between the two?
Brushless motors are better.
The differences are as follows:
1. Different service life
The brushless motor can work continuously for about 20,000 hours, and the conventional service life is 7-10 years.
The carbon brush motor can work continuously for about 5000 hours, and the conventional service life is 2-3 years.
2. The speed is different
The brushless motor can run at a high speed of 90-95m/s.
The running speed of carbon brush motors is much lower than that of brushless motors.
3. Different energy-saving effects
Relatively speaking, the power consumption of a brushless motor is only 1/3 of that of a carbon brush.
Disadvantages of brushed motors
(1) The friction is large, the loss is large
Old model friends have encountered this problem when playing with brushed motors before. After using the motor for a period of time, the motor needs to be turned on to clean the carbon brushes of the motor.
(2) High heat generation and short life span
Due to the structure of the brush motor, the contact resistance between the brush and the commutator is very large, which causes the overall resistance of the motor to be large and easy to generate heat. The permanent magnet is a heat-sensitive element. If the temperature is too high, the magnet will demagnetize , The performance of the motor is reduced, and the service life of the brushed motor is affected.
(3) Low efficiency and low output power
The heat problem of the brushed motor mentioned above is largely due to the fact that the current is done on the internal resistance of the motor, so the electrical energy is converted into heat to a large extent, so the output power of the brushed motor is not high, and the efficiency is not high. 
Brushless motor advantages
(1) No brush, low interference
The brushless motor removes the brush, and the most direct change is that there is no electric spark generated when the brush motor is running, which greatly reduces the interference of the electric spark to the remote control radio equipment.
(2) Low noise and smooth operation
The brushless motor has no brush, the friction is greatly reduced during operation, the operation is smooth, and the noise is much lower. This advantage is a huge support for the stability of the model.
(3) Long life and low maintenance cost
Without the brush, the wear of the brushless motor is mainly on the bearing. From a mechanical point of view, the brushless motor is almost a maintenance-free motor. When necessary, only need to do some dust removal maintenance. Comparing the previous and the next, you will know the advantages of the brushless motor over the brushed motor.
But everything is not absolute. The performance characteristics of brushless motors, such as excellent low-speed torque performance and large torque, are irreplaceable for brushless motors. However, in terms of the ease of use of brushless motors, as the cost of brushless controllers decreases The trend and the development of brushless technology at home and abroad and market competition, the brushless power system is in the stage of rapid development and popularization, which has also greatly promoted the development of model sports.
4. Different maintenance
Carbon brush motors are easily damaged, and the maintenance cost is much higher. The brushless motor is not easy to be damaged, the maintenance frequency is low, and the cost is low.