Learn how to replace worn cogs on your rear cassette.
Tools Needed:
- 15mm open-ended wrench or socket
- Large spanner
- Chain whip
- Cassette locking tool
- Replacement cogs
Procedure:
-
Remove Rear Wheel:
- Shift down to the smallest cog (highest gear).
- Loosen the 15mm nuts on both sides of the axle to remove the rear wheel.
- Pull the derailleur back to drop the wheel out of the frame easily without interfering with the chain.
-
Remove Cassette:
- Remove the 15mm axle nut on the cassette side and the accompanying washer.
- Use the chain whip to secure the cassette by wrapping it around gear number three.
- Use the cassette locking tool and a large spanner to loosen the cassette lock ring.
- Remove the lock ring and bottom two cogs.
- Align and install the new bottom two cogs by matching the splines on the hub and new cogs.
-
Reinstall Cassette:
- Thread the lock ring by hand and use the lock ring tool to tighten (40 Newton meters).
- Reinstall the washer and axle nut, tightening them halfway.
-
Reinstall Rear Wheel:
- Lift the rear wheel into the dropout, looping the chain under the cassette.
- Align the chain with the smallest cog and roll the wheel into place.
- Ensure the brake rotor is aligned with the caliper.
- Hand-tighten the bolts to secure the wheel temporarily.
-
Final Wheel Alignment:
- Drop the bike onto the ground to use its weight for wheel alignment.
- Loosen both bolts slightly, wiggle the bike to ensure straightness, and then tighten the bolts securely.
-
Verify Tightness:
- Check and ensure that all bolts and nuts are tight before each ride.
Now, you're ready to enjoy your ride with the newly replaced cassette cogs.