Please check the points below:
①Check whether there is friction between the motor hub and the front fork. Please adjust the clearance by adding or removing washers between motor and the front fork;
②Check whether there is friction on the disc brake. Please adjust the position of the disc brake caliper to avoid the friction.
Check whether the spoke caps fall off or the spokes are loose. If the spoke caps fall off, you need to take off the tube and tire to remove the fallen spoke caps and tighten the spoke caps again;
④Check whether the brake disc attaching screws are too long and touch against the motor inside. You can remove the disc and the screws to try if there is still noise or not. If the disc brake screws are too long, please replace them with the shorter disc brake screws;