Here are the three important considerations with brakes for an electric bike:

Price & Maintenance: Mechanical brakes are going to be much lower in price initially. They are also easier to adjust than hydraulic brakes, but do require more adjustment. Hydraulic brakes will require periodic “bleeding” of the system most likely at your local bike shop. Hydraulic brakes will generally outlast mechanical brakes.

Stopping Power: Plain and simple hydraulic brakes have more stopping power than mechanical brakes. With a hydraulic system you are “multiplying” the force of your brake lever press.

Use Case: Heavier faster electric bikes are best suited for hydraulic braking systems. Whereas lighter electric bikes that aren’t going off road too often can certainly perform well with a mechanical braking system.

How do hydraulic and mechanical disc brakes work?

First of all, disc brakes require a rotor instead of traditional rim brakes. Then, both hydraulic and mechanical brakes have brake levers that pull the brake cables that activates the brake calipers to apply braking force.

The difference between the two happens at the brake caliper. For the mechanical disc brakes your stopping power is more dependent on how hard you are able to squeeze the brake lever to activate the caliper. Whereas, hydraulic disc brakes relies on hydraulic fluid to “push” your caliper against the pads to “grab” the rotor. 

When presented with the choice most cyclists prefer hydraulic calipers over mechanical calipers. For overall stopping power, hydraulic systems are the best choice. However, there are other considerations. The biggest one is price. You will find that mechanical brakes can be found at a much lower price than their hydraulic counterparts.

Also, mechanical brake systems are much easier to maintain and adjust than hydraulic brakes. You most likely will need a local bike shop to adjust your hydraulic system. However, not nearly as often as mechanical systems. This is another real benefit of hydraulic systems…much lower maintenance.

How about the brake rotors for an electric bike?

You will find there are three options of rotor size that are most common: 160mm rotor, 180mm rotor, and 203mm rotor. You will see the larger sized rotors on electric all terrain bikes, electric mountain bikes and overly heavy electric bikes. The higher surface area of the larger rotors allows for maximum performance of the brakes. Larger rotors with new pads are also the best for higher speeds.