Bedding Brakes
Bedding in brakes is an important process to perform anytime you have a new brake pad and rotor on a bike. Brake pads that are bedded properly form a transfer layer of material on the surface of the disc which improves overall "bite" and performance as well as reducing noise.
The reasoning behind bedding in new brakes is that it allows the two surfaces (brake pad and rotor) to become familiarized with one another and properly mesh together. When the new pads and rotor come from the factory they have a very smooth surface so it is important to bed the new brakes as they will create ultra-fine levels of wear at first which gives them a groove to follow as you ride more and more over time. Improper bedding can cause premature and uneven wear of your brake pads and may cause them to be noisy or perform less effectively. This is why you may notice poor performance when installing new brake pads on a significantly worn rotor or vice versa. The new, unworn part has trouble making good contact with the highly worn part. This is why we recommend changing brakes and rotors together if there are signs of significant wear.
Bedding your brakes is recommended for all disc brake applications mechanical and hydraulic, bikes, motorcycles, cars, etc.
Note: This entire procedure should be completed before riding the bike normally as the sooner you form these intentional wear, the better the brakes will perform over time and avoid issues like noise and pulsation.
Procedure:
Before starting it is beneficial to ensure your brake calipers are not incorrectly adjusted, crooked, or already rubbing.
Hop on your bike somewhere with plenty of room. ...
Sit down in the saddle, ride up to 15/20 mph, and apply the brakes evenly, dragging them without skidding, until the speed drops to a walking pace. (You can apply both brakes or focus on one at a time)
Release the brakes while you're still moving. (Do not come to a hard stop)
Repeat 10 times. ...
Below are some examples of uneven brake wear (Figure 6) vs new and even brake wear (Figure 7)
Figure 6 Figure 7
Below is a how-to video: https://www.youtube.com/watch?v=BWQxGzHQZVU&t=2s