How do I know I have this issue?
Your brake lever will rattle a little with a slight movement, especially when riding on uneven ground.
What causes this issue?
The brake lever can shake slightly when riding on irregular ground.
This is a relatively normal phenomenon and can vary slightly from bike to bike, depending on the exact dimensions of the brake and the lever.
This will also likely happen more over time, as the bike ages.
How to fix this issue?
The noise can sometimes be decreased by slightly tightening the lever screw with an Allen 2mm key.
Be careful - don't over tighten it, because the screw is very fragile!