Replace wheel bearings

Wheel bearings are pressed tightly into the hub. Removing them without a puller and fitting them without the right driver damages the new bearing or the hub, even if it looks fine. This page is an assessment and hand-off: what to confirm first, what the workshop should do and what to ask for.

Safety

• A bearing that fails at speed can lock or let the wheel tilt. Stop riding a wheel with clear side play.
• Bearings can burst when pressed. Workshops should wear a face shield.

Check first (at home)

• Confirm the fault with Check wheel bearings. Rule out a loose axle, brake drag and swingarm or steering play.
• Read the number on the old bearing seal if you can see it, so the shop fits the same size and seal type. K-Light 125: front 6202-2RS, rear 6303-2RS.

What the workshop should do

1. Remove the wheel and keep spacers and the speedo drive in order.
2. Lever out the hub oil seals with a cloth under the lever to protect the rim and hub.
3. Remove the bearings with a puller, or drive them out through the hub with the centre spacer pushed aside.
4. Clean the hub bore and check it for scoring or a loose fit. A bearing that spun in the hub needs a hub repair or a new hub.
5. Always fit new bearings. Drive them in only on the outer race, with a driver the same size as the outer race. Pressing on the inner race damages the balls.
6. Fit the centre spacer between the bearings. A missing spacer lets the axle squeeze the inner races and the wheel drags.
7. Fit new seals with grease on the lips. On the front, grease the speedo drive and make sure its tangs sit in the hub slots.
8. Refit the wheel, tighten the axle to the bike's value, spin the wheel, check the brake.

What to ask for

• Both bearings in the hub replaced, not only the noisy one.
• New seals.
• The old bearings, so you can feel the roughness.
• On the rear, ask them to check the cush drive rubbers and the sprocket carrier bearing while the wheel is out (Check the cush drive rubbers).

Do not attempt at home

• Hammering a bearing in on its inner race or with a socket that touches the balls or seals.
• Heating an alloy hub with a flame.
• Reusing bearings that were removed with a puller.

Reference values (K-Light 125)