The cassette comes off for deep cleaning, replacing worn sprockets, hub servicing or replacing drive-side spokes. The job is simple, but you do need two special tools.
The most common problem is a lockring that has seized after winters of salt and damp. Here is how to remove the cassette without damage and how to refit it.
What you will need
Important: The chain whip can slip, so keep your hands clear of the sprocket teeth and wear gloves. Keep penetrant off the brake disc: lay the wheel disc-side down on a cloth or remove the rotor.
Step 1
Choose the right tool
Lockring tools differ in the number and shape of splines for different freehub standards. Check the lockring and use a tool that fits snugly with no play. A chain whip suits any cassette of the right speed count.
Step 2
Remove the wheel
Shift onto the smallest rear sprocket. Open the quick release or axle, pull the derailleur back and lift the wheel out. Lay it on a sturdy bench, cassette side up.
Step 3
Fit the tool and chain whip
With a quick release, remove the springs and thread the skewer through the tool so it cannot jump out of the splines. Wrap the whip chain clockwise round a large sprocket with the handle pointing left.
If the lockring has not been off for a long time, apply WD-40 Specialist Penetrant to its splines and thread and wait 5-10 minutes.
Step 4
Undo the lockring
Put the spanner on the tool and push spanner and whip towards each other: spanner anticlockwise, whip holding the cassette. The lockring breaks free with a loud crunch, which is normal, as that is its serrations releasing.
After the first turn, remove the skewer, unscrew the lockring by hand and slide the cassette off. If it comes apart into separate sprockets, thread a cable tie through them at once to keep the order.
Step 5
Inspect and clean the freehub
Wipe the freehub body with a cloth and WD-40 Multi-Use to remove dirt and old grease. Check the splines for gouging: if sprockets have bitten into an alloy freehub, file off the burrs with a fine file.
Apply a thin film of WD-40 Specialist White Lithium Grease to the splines so the cassette comes off easily next time.
Step 6
Refit the cassette
Line up the wider spline on the sprockets and freehub and slide the sprockets on in order with their spacers. Thread the lockring on by hand, then tighten with the tool without the whip, ideally to about 40 Nm with a torque wrench.
Refit the wheel, check the chain shifts across every sprocket and the brakes work.
Tip: If the cassette refuses to budge, do not add a cheater bar and jerk it: reapply penetrant, give it longer to work and apply steady force. A jerk is more likely to strip the tool splines than free the lockring.
What next
Remove the cassette at least once a season for cleaning, even if the sprockets are not worn, so the lockring never seizes. After winter rides, wipe the visible freehub and sprockets with a cloth dampened with WD-40 Multi-Use.
These uses come from the experience of WD-40 users in many countries. Always follow the instructions and warnings on the product label.
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