Repair guides › Wheels & Tires
Check and replace sealed hub bearings
A hub clamped by a 12, 15 or 20 mm axle that threads through the frame. Stiffer and always aligns the disc rotor the same. Cartridge bearings pressed into the shell. Axle threads into the dropout.
Open this job in RideLoadout▶ Watch it done
Tools
- Ball-end hex key set (1.5–10 mm): Park Tool HXS-1.2 Professional L-Shaped Hex Set ($$)
- Shop rags + nitrile gloves: shop towels and nitrile gloves ($)
- Bike grease: Park Tool PPL-1 PolyLube 1000 ($)
- Digital calipers: Clockwise Tools DCLR-0605 IP54 Digital Caliper ($$)
- Soft mallet + star-nut setter: Rubber mallet + star nut setting tool ($$)
- Hub bearing press: Wheels Manufacturing Hub Bearing Press Essential Kit ($$$)
Compare Good, Better and Best for each tool
Steps
- Spin the axle in the hub with your fingers: any roughness or play means worn bearings.
- Pull off the end caps (most pull straight off).
- Drive the axle out with a soft mallet, taking one bearing with it.
- Read the bearing size printed on the seal (e.g. 6902) and order replacements.
- Press new bearings in square on the outer race with a press or a socket that matches the outer race (never hammer the inner race).
Diagram
Cut in half, seen from behindWheel axle and hub (either wheel)
Signs it needs doing
- Play
- Rough spin