Several factors can contribute to a motorcycle vibrating when braking. Here are some common causes:
Warped brake rotors: The brake rotors, also known as brake discs, can become warped due to excessive heat buildup or uneven wear. When the brake pads make contact with the uneven surface of the rotors during braking, it can cause vibrations that are felt through the handlebars or foot pegs.
Worn brake pads: If the brake pads are worn out or unevenly worn, they may not provide consistent contact with the rotors during braking. This uneven contact can lead to vibrations as the pads grab and release the rotor surface.
Loose or worn wheel bearings: Wheel bearings that are loose or worn can cause the wheel to wobble or vibrate during braking. This can be felt as a pulsating sensation in the handlebars or foot pegs.
Suspension issues: Problems with the front or rear suspension can also contribute to vibrations during braking. Worn-out suspension components or improper adjustment can lead to instability and vibrations when the brakes are applied.
Tire issues: Uneven tire wear, tire imbalances, or insufficient tire pressure can cause vibrations during braking. If the tires are not properly balanced or if there are irregularities in their tread pattern, it can affect the bike's stability and cause vibrations.
Brake caliper issues: Faulty brake calipers, such as sticky or seized pistons, can cause uneven braking pressure on the rotors. This can result in vibrations during braking.
It's essential to diagnose and address the specific cause of the vibration to ensure the motorcycle's safety and performance. If you experience persistent vibrations while braking, it is recommended to have a qualified motorcycle mechanic inspect and troubleshoot the issue.