Check steering bearings regularly
A perfectly adjusted steering bearing is essential for safe riding behaviour. If the bearing is too loose, not only will every cornering manoeuvre be unstable - the bike can also rock dangerously at high speeds. If the bearing is too tight, the steering becomes stiff.
Checking the bearing play is a matter of seconds: Pull the front brake, then slide the entire wheel forwards and backwards. Place the fingers of your other hand on the upper bearing shell: if it moves against the frame, there is still play in the bearing - it needs to be tightened. Lift the front wheel and check whether the front wheel can be swivelled from left to right without resistance. The handlebars should only turn under their own weight. If it does not, the bearing is too tight.
Set the game correctly
The bearing play is adjusted using the screw at the top of the steerer tube. First loosen the clamping screws on the side of the stem until it can be turned very easily against the fork. Two to three turns are usually sufficient. Turn the upper adjustment screw clockwise until you feel slight resistance - but do not tighten it! Retighten the stem bolts to the specified torque and check the play again.
Recognising wear on the steering bearing
Steering bearings generally last the life of a bicycle. However, if the bike is ridden a lot, the bearings may need to be replaced at some point. Signs are problems with adjustment - the bearing is too loose or too tight - or if the handlebars lock in a straight position. As there is a wide range of different bearings, it is best to organise new parts via the dealer or the manufacturer. If you can't get any further there, special templates can help you to at least determine the exact dimensions of the bearings.
Professional tips
>> When disassembling the headset, memorise the sequence and alignment of the individual parts. An incorrectly inserted or missing part means that the headset cannot be adjusted correctly.
>> If the headset keeps coming loose, it may be because the clamping cone in the steerer tube slips upwards under load. A little assembly paste can improve the hold, otherwise use a different clamping cone. It should extend as far as possible into the steerer tube and the clamping surface should be structured.
>> If the steering bearing cracks, this is often caused by dirt or a lack of lubrication. Clean all individual parts thoroughly, including the spacers and the contact surfaces of the stem. You can apply a thin film of grease to all metal components; however, grease on the carbon fork steerer tube is taboo.
Jens Klötzer
Editor
