Adjust The Bike Headset On A Threaded Steerer

Some bike headsets have a knurled ring on
the adjustable race, these can be adjusted with a large pair of slip-joint pliers. If
it has flats, either a hexagon or two parallel flats, you will need a bike headset spanner
of the correct size to turn it. A bike headset spanner is thin so it can turn on the nut’s
narrow flats. The lock-nut on top can be turned with a second bike headset spanner but it
may be possible to use a large adjustable spanner for this, so you may be able to do
the job with only one bike headset spanner. Stand in front of the bike, facing the handlebars,
with the front wheel between your legs and your head on the centre-line of the bike.
Make sure the tool you’re using fits the top nut, the lock-nut. Hold the wheel still
with your legs and turn the lock-nut anti-clockwise. Once the lock-nut is released the adjustable
race can turn. If the bearing is too loose, screw the adjustable race down – clockwise
– as far as it will go with your fingers or using a tool gently, then turn it back
a quarter turn. If the bearing is too tight, turn it anti-clockwise a quarter turn. Check the bearing to see if it’s within
the target of ‘free to turn’ and ‘not too loose’(link). If it’s too loose or
too tight repeat the previous step making finer adjustments. Once you have the adjustable race in a good
position hold it still with a bike headset spanner or big pliers. Screw the locknut down
until it jams against the adjustable race to lock the two parts together. Make a final check that the bearing is in
the target zone.