The term 'handlebar part' refers to the GRIP, which is a four-letter word. The GRIP is a component of a handlebar, which is a bar that is attached to the steering mechanism of a bicycle or motorcycle. It is used to steer the vehicle and provide stability. The GRIP is the part of the handlebar that the rider holds onto in order to control the vehicle. It is usually made of rubber or foam and provides a comfortable and secure GRIP for the rider.