Steering Race Set for Aprilia / Piaggio Various Models.
Steering races commonly develop a notch in the centre of the steering, due to most riding being in a straight line. This usually manifests as a feeling that the steering always wants to center itself (sort of like how a car door wants to hold in certain positions as it is opened).
This is dangerous, as it effects the handling characteristics of the bike particularly in cornering situations.
Changing the steering race is a time intensive job, make sure you know what you’re up for before you start stripping the bike!