Tech Tip 17

HEADSET SERVICE 2
Servicing a "CARTRIDGE" bearing headset

Tools for the job:
The usual

Difficulty:

Time:
10-20mins

Cartridge headsets run on modular bearing units that sit inside the headset cups. They are better sealed and last longer and require less servicing that the cheaper ball and cup variety covered in our "Loose Ball Bearing Headset Service"

With cartridge bearings it is not possible to strip the units down to their individual bearings, but the seals can be removed by allowing the bearings to be seen and so that you can clean and regrease them.

1. Remove top cap and stem/bar and remove forks and strip down the headset. If you can remove the bearing units from their relevant headset cups, do so – this isn’t always possible on some headsets. Both bearing units are often the same, but don’t mix up the upper and lower sets, just in case they are different. Taking care not to damage the seals, use a sharp edge (small flat head screwdriver or small knife) to get the seals out of their seatings to allow access to the bearings. The seals are normally black, blue or orange and are made of neoprene so you should be able to figure out which bit your removing.

2. Once the seals are out this will expose the bearings inside. Flush out all the old grease with a good degreaser - leave them soaking in degreaser for a while if they are really dirty - don't put the seals in degreaser however as you will damage them! While your bearings are being degreased use the time to wipe clean all the other components of the headset. Squeeze fresh grease into the bearings and give the 'races' (the metal surfaces the bearings spin on) a spin to work it in. Note: Don’t overfill the bearings with grease, as this will cause the seals to pop out.

3. Once you’re done regreasing, push the seals back into place and wipe up any excess grease. Place the bearing units back into their corresponding cup. Make sure any other seals are correctly in position.

4. Install all the components for the top half of the headset. - that’s the seal if present, the compression ring (making sure it’s the right way up, washers and the top cap).

5. You can now replace the stem and preload cap. Always make sure the top of the steerer sits below the top of the stem – this should be a gap of about 3mm. That gap is very important and allows the preload cap to push down on the stem, which compresses the headset to remove the play. With the bike on the floor, preload the headset until all the play is removed, but not so much that the headset binds. A properly adjusted headset should spin freely and have no play or tight spots.

6. Check for play. Don’t mistake play in the headset for play in the fork. A good tip is to engage the front brake, place your other hand around the bottom cup and rock the bike back and forth. You can feel any play that’s coming from the headset.