Wheel / sprocket bearing replacement.

Front wheel bearings.

• Dimensions:
  OE: NTN 6004LU.
  Sealed ball bearing ID:20mm, OD:42mm, W:12mm
• Remove front wheel.
• Use a puller to tap out the 20mm shaft bearings or if you don't have
  that I suppose you could use a screw driver and hammer to knock out the
  bearing but be carefull to keep the beaing straight and not to damage
  the light alloy housing.
• Use a bearing driver (42mm OD) to drive in the new bearings or if you
  don't have one of them, use a 1/2" drive socket (27mm maybe) that has an OD
  of just under 42mm to gently tap in the new bearing, be sure to keep the
  bearing straight as you tap it in, don't tap the inner race of the bearing.

Rear sprocket carrier bearing

• Dimensions:
  OE: Koyo 6007 2RS.
  Ball bearing, two rubber seals, ID:35mm, OD:62mm, W:14mm
• You don't have to remove the rear wheel, but I would remove the rear
  wheel because I think it makes it easier.
• Unstake and remove the large 35mm lock nut using a 46mm socket.
• To make it easier I'd remove the chain guard and take the chain off the
  the sprocket and move the chain far away from the sprocket.
• The drive flange (the thing that the sprocket is bolted onto) is held
  in place by it's bearing which is press fitted, if it hasn't been removed
  recently it may be slightly seized, gently tap the rear sprocket with a
  hammer then rotate it 30° and tap it again, rotate and tap, rotate and
  tap until it starts to move. The drive flange is made of cast aluminium and
  is very easy to break.
• Drive the old bearing out of the drive flange, grease everything, and
  install the new bearing
  
• Tighten the 35mm locknut to 160 Nm, rear wheel nut:120 Nm, pinch bolt:75Nm.
• While your doing this job you could easily replace the final drive
  dampers, 5 required (AKA cush drive rubbers), the rubbers need servicing if
  you can turn the sprocket a liitle bit without moving the wheel. If you
  dont want to pay for new rubbers I suppose you could cut up a rubber tube
  and put the pieces in beside the rubber blocks to fill up the space.

Rear wheel bearings.

• Dimensions:
  • Left hand bearing: Double roller bearing made up of two Koyo 6908LU,
    ID:40mm, OD:62mm, W:12mm, ball bearing with one rubber seal (two required).
  • Right hand bearing: Needle roller bearing with no inner ring and one
    rubber seal, a seperate independant rubber dust seal (50x62x5) is required
    to fully seal the bearing.
    OE: NTN OU, 8Q-NK 50x62x25-1
    NK 50/25, ID:50mm, OD:62mm, W:25mm.
• Ensure bearings are greased before installation (they usually are pre-greased).
• Remove rear wheel and rear sprocket drive flange as described in previous section.
• The final drive damper DRIVEN flange (the thing behind the drive flange)
  is held in place on splines which might be slightly seized, tap it off but
  be carefull as it is very very easy to break.
• Remove the spindle, a part of the spindle acts as a beaing race, be
  extremely carefull not to damage or contaminate it.
• Remove the large 75mm external circlip on the right hand side of the
  bearing carrier.
• Remove the bearing carrier.
• Remove the dust seal for the needle bearing.
• Remove the circlips that holds the bearings in place.
• The bearing housing is made of light alloy and is very easy to break
  by tapping or forcing.
• Use a screw type bearing puller to pull out the 40mm shaft ball
  bearings, or if you don't have one of these you could use a 50mm OD(or
  slightly less) pipe and a threaded rod and screw out the bearings or you
  you could tap out the bearings (bearings are not re-useable
  after being tapped like this)(hard tapping might crack bearing housing).
• Romove the inner dust seal of the needle bearing.
• Remove the needle bearing by using a screw type bearing puller or
  you could use a 56mm OD pipe with a threaded rod etc. and screw out the
  bearing, or you could tap out the bearing with the pipe but that's risky.
• Drive (by screwing) in the new bearing with the appropriate bearing
  driver, or with the pipes, or I used a 46mm socket and a M16 threaded rod and
  a very very large washer with a 16mm hole in it.
• Replace circlips, install dust seal.
• Install bearing carrier in bike and fit the 75mm circlip.
• Clean and grease splines on spindle and flange (molygrease or copper grease).
• Re-assemble, tighten 35mm lock nut to 160 Nm, rear wheel nut to 120 Nm and
  bearing carrier pinch bolt to 75 Nm.