Chatter

Chatter is a fast, repeated vibration or oscillation of a component. On motorcycles the term usually means the front or rear wheel hopping rapidly on the road surface, felt through the bars or seat, often when braking hard or at high lean angles in corners.

Suspension chatter happens when the tyre, suspension and chassis get into a resonance the dampers can't control, and the tyre briefly loses consistent contact with the road. Causes include incorrect damping or spring settings, worn shocks, a tyre with the wrong pressure or construction, and a rough surface. It is most common on track.

Other forms are brake chatter, caused by warped discs or pad deposits, and clutch chatter, a juddering take-up from worn or glazed clutch plates or a notched basket.