How to service a hub

Service your wheel bearings for a smoother ride

If your wheels feel rough when you spin them, it could be that you need to service your hubs. Usually the problem will be caused by wear in the small metal balls in your hub, known as wheel bearings.

Wheel bearings wear over time - this can lead to excess movement and will cause the wheel to rock on its axle.

There are two types of bearing, sealed (or cartridge) bearings and non-sealed (standard or open). Both will run more smoothly if they are lubricated, so a regular service can extend the life, although they will eventually wear out to the point that they need to be replaced.

Here we’ll talk you through how to service both of these types.

Standard hub

Tools required

Tools required for standard hub servicing:
Tools required for standard hub servicing:

  • Cone spanners - usually 15 or 17mm
  • Grease
  • A magnetic hex screwdriver or pick
  • A chainwhip and chain removal tool
  • Adjustable spanner
  • Degreaser
  • Paper cloth
How to service wheel bearings on a standard hub

Video: How to service wheel bearings on a standard hub

1 We are using a rear wheel, but the procedure is the same for a front - except it doesn’t matter which side you undo first. For the rear, remove the cassette from the freehub body.

Undo the lock nut on the non-driveside by using a cone spanner to hold the cone and another to undo the nut. Remove the locking nut and spacer by hand.

Undo the locknuts on the non-driveside:
Undo the locknuts on the non-driveside:

It’s a good idea to take note of the order as they will need to be returned.

Hold the lock nut on the drive side with one spanner, then undo the non-driveside cone with the other, and wind off by hand. You should now be able to remove the axle from the hub from the freehub side.

2 Remove the bearings from the race - a magnetic positive screwdriver will allow you to lift the bearing out.

Remove the bearings, and clean them using degreaser and paper cloth:
Remove the bearings, and clean them using degreaser and paper cloth:

You’ll now need to clean the bearings. Use a degreaser and some paper cloth, making sure you fully clean away all old grease before proceeding.

Take a close look at the bearings and the cone. If there’s sign of wear on them, they'll need replacing

3 Take some grease and apply it to the bearing race in the hub. You can now place the bearings into the grease - they should stay in place. Again, a magnetic screwdriver makes the job easier.

Apply grease to the bearing race, then return the bearings to the hub:
Apply grease to the bearing race, then return the bearings to the hub:

When all of the bearings are in place, you can then return the axle and gently turn it to ensure they are installed correctly. Remove the axle then repeat the process on the other side.

4 Now return the axle to the freehub side. Press it against the bearings and rotate to check it’s seated correctly. Return the cone to the non drive side of the axle and screw until it contacts the bearings. It doesn’t need to be very tight - finger-tight will do.

You can then spin the axle to make sure it rotates cleanly, and jiggle the axle to ensure there is no play.

You may need to adjust the tightness of the cone to stop any play or drag - if it’s too tight the hub will not spin freely conversely if its too loose there will be play in the axle. This can sometimes be a matter of trial and error so may take a few attempts.

Return the other nuts, spacers and seals to the non drive side of the axle.

Then while holding the cone in place, use the other spanner to tighten against the locking nut. It’s important to check the axle still rotates freely at this point as it’s possible to tighten the cone in the procedure.

5 Finally, refit the cassette to the freehub body, replace the quick release skewer and return to the bike.

Cartridge hub

Tools required

  • Multi-sized cone spanners: 13, 14, 15 and 16mm
  • Open-end 15mm spanner
  • 5mm Allen keys
  • Solid rear axle
  • Nylon mallet
  • Small screwdriver
  • Bearing grease
  • Special tools or alloy tube to press the bearings

Servicing a front hub: cartridge hub:
Servicing a front hub: cartridge hub:

1 The axle will probably have at least one end with a removable dropout guide/locknut, which you’ll need to take off. In most cases, this can be done by inserting a 5mm Allen key at both ends and turning anti-clockwise. You might have to put some muscle into it, so use a little cheater bar or long keys for this. Keep track of any washers and their positions between the spacers and axle. The silver spacer doubles as both dust cap and decorative element in most hubs. It might take some strength to pry off; it will likely be held by a rubber O-ring between it and a groove on the axle. Alternatively, some hubs (eg. Mavic) have a threaded cap to allow for bearing adjustment, so just unscrew these first.

Servicing a front hub: extract the bearings:
Servicing a front hub: extract the bearings:

2 In order to remove the cartridge, you’ll first need to support the hub in such a way that you won’t damage it. For example, you could use a delrin tube of the sort you can pick up from Hope. You’ll need to strike a few sharp blows to get the cartridge out, so a rubber mallet probably won’t do; a resin mallet or a hardwood block with a lump hammer are much better at delivering the force necessary to dislodge it. It’s also important to avoid whacking your axle from the side without buttressing the hub using the special tool for the job (as shown on the far left of the image above). After all, you don’t want to damage your axle and spokes, do you?

Servicing a front hub: catch my drift?:
Servicing a front hub: catch my drift?:

3 The next operation removes the bearing left behind. Flip the wheel over and position the hub with the bearing facing down. Make sure the hub is sufficiently supported by the flange and there’s room for the bearing to come out. Carefully position either the axle or a suitable drift tool (an aluminium tube or even an old solid axle with a cone or nut threaded partially onto it) and knock the bearing out with a few sharp blows. Be aware that you might have to hit it pretty hard if it’s a tight fit. Clean with degreaser and a rag, including the hub flanges around the spoke anchor points, and inspect for cracks or corrosion. You’ll need a new hub or wheel if cracks are spotted.

Servicing a front hub: insert new bearings:
Servicing a front hub: insert new bearings:

4 Spread a light coating of grease or oil on the contact surfaces (the outside and inside of the new cartridges, the hub bearing cup and the axle). If the grease is too thick between the bearing and the hub, it could prevent it from seating completely. The new bearing should only be driven using the outer race. Use the old bearing or a socket of exactly the same diameter. Keep in mind that the bearing races are made of hardened steel and are therefore potentially brittle. Wear protective goggles and make sure the contact area between the drift edge and the outer race edge is maximised by being perfectly aligned. You’ll know the bearing is seated when the blows suddenly firm up.

Servicing a front hub: gentle taps:
Servicing a front hub: gentle taps:

5 With the first bearing side down, slide in the axle from the inside. Position the second cartridge on top and using the appropriate drift tool, drive it in with a few careful mallet or hammer blows. Don’t allow the bearing to go in askew. Attempting to force it in if it’s badly out of line will only get it jammed and make it harder to install, creating ridges that could prevent it from seating correctly. Thread the dust caps or slide spacers back on with a little oil, then feel for buttery smoothness. If it’s tight, strike a couple of blows on the opposite end (the end inserted first into hub). This should balance out the bearing load and smooth it out. Ride on, brothers and sisters!

This article was published by BikeRadar, the world's leading source of bike reviews, gear reviews, riding advice and route information
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