When brake pads are new or warn, they may produce a chirping noise when activated. The steps below will help isolate the problem and fix it.
Please note these procedures are best performed by trained e-bike repair shops. Some of these repairs require specialized tools and skills that e-bike shops have.
1) If you are in Europe, please check to make sure the brake pads or not blue. Some bikes shipped with Blue pads which should be replaced with bi-material red pads.
2) If the brake pads are new, please follow the brake break in procedure as in the below video.
3) Remove the brake caliper and confirm the pads are not worn out. Some pads have a circular wearing indicator. If you can see the indicator the pads are worn out and need to be replaced. Check to make sure that the pad and metal backing material measure more than 2.5 mm thick (3/32 inch) per the diagram below.
4) Is the brake mechanism sticky or has uneven motion?
Follow the procedure in the video below to clean, oil, and exercise the brake mechanism.
Learn more about keeping your bike in optimal condition.