Adjust A Cup And Cone Front Hub

Introduction

Some modern front hubs are fitted with sealed cartridge bearings that can't be adjusted. The bearings are simply replaced with new ones. Cup and cone bearings can be adjusted and serviced.

Step 1

<h3>Step 1</h3><p>An adjustable front hub has a lock-nut on the outside, then sometimes a washer, then the cone which has two narrow flats. Cone spanners are thin spanners that fit onto the narrow flats. You need one that fits the narrow flats exactly. This is likely to be somewhere between 13mm and 16mm. Working on the wheel off the bike is easiest if you use an axle vice; a specially designed tool that fits in a bench vice. To use an axle vice remove any quick release skewer.
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Cone Spanners

An adjustable front hub has a lock-nut on the outside, then sometimes a washer, then the cone which has two narrow flats. Cone spanners are thin spanners that fit onto the narrow flats. You need one that fits the narrow flats exactly. This is likely to be somewhere between 13mm and 16mm. Working on the wheel off the bike is easiest if you use an axle vice; a specially designed tool that fits in a bench vice. To use an axle vice remove any quick release skewer.

Pro Tip

Front hubs are symetrical, they work either way round. It’s conventional to keep the right side locked tight and always adjust the left side. This is because if the left side becomes loose in operation, the turning wheel will loosen the bearing. If the right side comes loose, the turning wheel may tighten the bearing and cause catastrophic damage, or even a crash.

Step 2

<h3>Step 2</h3><p>Hold the axle still with a cone spanner on the cone and turn the lock-nut anti-clockwise to unlock the bearing. If the wheel is off the bike you may be able to hold the lock-nut with a normal open-ended spanner. If you want to work with the wheel on the bike another cone spanner may be necessary.
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Unlock front hub

Hold the axle still with a cone spanner on the cone and turn the lock-nut anti-clockwise to unlock the bearing. If the wheel is off the bike you may be able to hold the lock-nut with a normal open-ended spanner. If you want to work with the wheel on the bike another cone spanner may be necessary.

Step 3

<h3>Step 3</h3><p>Screw the cone in or out to tighten or loosen the bearing on the front hub. When you move it out hold the axle still with a spanner on the cone on the opposite side. When you move it in hold the axle still with a spanner on the lock-nut on the other side. Make small adjustments and check the bearing between each.
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Adjust

Screw the cone in or out to tighten or loosen the bearing on the front hub. When you move it out hold the axle still with a spanner on the cone on the opposite side. When you move it in hold the axle still with a spanner on the lock-nut on the other side. Make small adjustments and check the bearing between each.

Step 4

<h3>Step 4</h3><p>Once the bearing is in the target zone of not-too-loose and not-too-tight hold the cone still and screw the lock-nut tight against it to lock the bearing on the front hub.
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Lock

Once the bearing is in the target zone of not-too-loose and not-too-tight hold the cone still and screw the lock-nut tight against it to lock the bearing on the front hub.

Step 5

<h3>Step 5</h3><p>Check the bearing and readjust if necessary. The act of locking may change the tightness of the bearing so if your first try at locking ends up too tight start again with the bearing very slightly looser.
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Check the front hub

Check the bearing and readjust if necessary. The act of locking may change the tightness of the bearing so if your first try at locking ends up too tight start again with the bearing very slightly looser.