Check your bearings

Some small amount of jog is acceptable from a bearing, but not too much.

Front wheel bearings.
2 sealed deep groove ball bearings, ID: 20mm, OD: 42mm, Width: 12mm, 6004 LU.

• If your front wheel bearings are worn out you may notice a rattle from the front
  wheel and your front brakes may become softer than usual.
• Lift the front wheel off the ground. Turn the handle bars until it contacts the
  frame, hold it tightly in this position.Try to jog the front wheel, then rotate the
  wheel slightly and try to jog it again, etc. If there is a jog then the bearings
  need to be replaced.
  
• Alternatively you can check the bearings when the front wheel has been removed
  from the bike. Simply turn the inner race of the bearing, it should turn smoothly
  and quitely, if it doesn't then the bearings needs to be replaced.

Steering stem bearings.

• If you hear a "click" sound when you suddenly apply or release the front brakes
  then your steering stem bearings may be worn.
• Lift the font wheel off the ground and check for a jog in the steering stem.
  Check for a jog in several steering positions. If there is a jog then the
  steering stem bearings will need to be tightened or possibly replaced.
  

Rear wheel bearings.
Left: Two ID: 40mm, OD: 62mm, Width: 12mm, Two ball bearings 6908 LU (double roller).
Right: ID: 50mm, OD: 62mm, Width: 25mm, needle bearing supplied with no inner ring,
The rear wheel spindle acts as the inner race.

• You may notice a clicking sound from the rear wheel, or that your rear brakes
  are softer than usual.
• Put the bike on it's center stand and into neutral. Try to jog the rear wheel,
  then rotate it and try to jog it again etc. If there is a jog then the bearings
  will need to be replaced (very expensive for the bros/hawk).
• Ensure all nut/bolts are torqued up before condemning the bearing
  Rear wheel nut: 120 Nm, bearing carrier pinch bolt: 75 Nm.

Rear sprocket carrier bearing.
Deep groove ball bearing, ID: 35mm, OD: 62mm, Width: 14mm, 6007 RS.

• Put the bike on it's center stand and into neutral. Grab the rear sprocket
  and try to jog it, rotate it and try to jog it again etc. If you can jog the
  sprocket then the sprocket carrier bearing needs to be replaced.
  Note: Make sure it not the rear wheel bearing thats worn.

Gearbox output shaft bearing / front sprocket carrier bearing.

• Take the front sprocket off it's shaft and try to jog the shaft in several
  different positions. If there is a jog then the bearing needs to be replaced.
  Note: it's normal to be able to pull the shaft in and out by half a milemeter or so.

Swing arm bearings

• Double roller (two ball bearings) on right, needle on left.
• Put the bike on it's center stand and try to jog the swing arm.

And there are many other bearings that should be checked also.