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    Adjust A Bike’s Cup And Cone Bottom Bracket

    Introduction

    Some bottom brackets can be adjusted to tighten or loosen the bearing. Others are fit-and-forget, when they wear out the whole unit must be replaced. Some have cartridge bearings that can be replaced. Identify an adjustable bearing by the lock-ring on the left-side cup

    Step 1

    <h3>Step 1</h3><p>Depending on the way the tools fit it may be easier to do this job with the left-hand crank off. It's useful to have one crank on the axle for testing the tightness of the bearing. </p> </div>

    Remove a crank?

    Depending on the way the tools fit it may be easier to do this job with the left-hand crank off. It's useful to have one crank on the axle for testing the tightness of the bearing.

    Step 2

    <h3>Step 2</h3><p>If the bearing is adjustable the left-hand cup will have a lock-ring around the outside. Turn this anti-clockwise to unlock the cup. This is easiest with a lock-ring spanner that fits the notches on the ring exactly, you can also use a universal tool with one tooth or a tap it round with a hammer and an old screwdriver. </p> </div>

    Unlock

    If the bearing is adjustable the left-hand cup will have a lock-ring around the outside. Turn this anti-clockwise to unlock the cup. This is easiest with a lock-ring spanner that fits the notches on the ring exactly, you can also use a universal tool with one tooth or a tap it round with a hammer and an old screwdriver.

    Step 3

    <h3>Step 3</h3><p>Once the lock-ring has moved back the cup can move. If it has hexagonal flats turn it with a spanner. If it has holes use a peg spanner. </p> </div>

    Tools

    Once the lock-ring has moved back the cup can move. If it has hexagonal flats turn it with a spanner. If it has holes use a peg spanner.

    Step 4

    <h3>Step 4</h3><p>If the bearing is too loose screw the cup inwards clockwise. If it's too tight screw the cup outwards anti-clockwise. Make small adjustments and check between them. </p> </div>

    Adjust

    If the bearing is too loose screw the cup inwards clockwise. If it's too tight screw the cup outwards anti-clockwise. Make small adjustments and check between them.

    Step 5

    <h3>Step 5</h3><p>Once the bearing is in the target zone hold the cup still with a tool and screw the lock-ring down against the frame to jam the cup in place. </p> </div>

    Re-lock

    Once the bearing is in the target zone hold the cup still with a tool and screw the lock-ring down against the frame to jam the cup in place.

    Step 6

    <h3>Step 6</h3><p>Make a final check and replace the crank. </p> </div>

    Finish

    Make a final check and replace the crank.