OEM & Aftermarket Motorcycle Fork Components
Choosing motorcycle fork components is important...
Motorcycle Fork Components FAQ
Also pay attention for any spots where the front end hesitates when you turn the bars side, to side; this could be a notch in the bearing race from wear. In this case you should replace your neck bearings and races.
Another way you should check to see if the bearings are loose is by grabbing the forks and trying to move them side, forward and back. If you feel them wiggle and there is play at the steering head, tighten your bearings to spec and then test them again to see if they operate smoothly. If they don’t, it is probably time to change your bearings. You can also gauge the tightness of the bearings by, with the front of the motorcycle off the ground, aligning the wheel straight forward and seeing how easily it 'flops' to the side. It shouldn't slam to the side, it should be a nice even movement."