With regular maintenance, most motorcycle head stock bearings will last the lifetime of the bike. The exceptions to this rule are where a bike has been involved in a heavy frontal impact, or has been driven in a straight line for many miles. Both of these conditions will tend to damage or wear the bearings at one specific location; the rider will notice a slight resistance as the handlebars are turned about this point (often referred to as notchy).

The types of head stock bearings fitted to a motorcycle vary slightly. Early machines used the ball type bearing, but the vast majority use the tapered roller variety. The free play in this type of bearing is controlled by the amount of torque applied to the clamping nut—the greater the torque, the tighter the steering.

During routine maintenance, it is advisable to check the free play of the head stock bearings and to check that the clamping nut has not backed off (use a paint stick to mark the nut after adjusting).

A simple check for movement is to place a finger or thumb between the locking nut (ring) and the frame then (see photo). With the front brake applied, rock the motorcycle forwards and backwards. Excessive free play will be felt immediately with this method.

Removing the free play is simply a matter of tightening the lower clamping nut. However, the mechanic must not over tighten the nut as the steering will become difficult to turn. If the adjustment has been done correctly, with the machine on a center stand, the handlebars should move freely and there should be no free play at the nut.