What “true” means
A wheel is “true” when it spins in a straight line, with the rim running centred between the fork or frame without wobbling from side to side. It should also be round, without high or low spots. A wheel that is out of true will often feel odd at speed, may rub the brake pads or frame, and can be weaker than a properly built one.
Wheels depend on tension from the spokes, which are pulled tight against the rim. Changing the tension on one spoke affects its neighbours, which is why truing is more subtle than it looks. This article covers how to check, not how to repair, because wheel work is usually best done by someone with the right stand, tools and experience. It is general information, so follow the instructions for your own wheels.
A first look: is the wheel secure?
Before judging the wheel itself, make sure it is seated properly. A wheel that is not fully in the dropouts, or an axle that is loose, can look like a wheel problem and is also a safety risk. A quick wheel retention check confirms that quick releases or thru-axles are fitted and closed as the maker describes. If the wheel feels loose, correct that before doing anything else.
The spin test
Lift the bike so the wheel is off the ground, or turn the bike upside down on a stable surface if you can do so safely and without damaging cables or accessories. Spin the wheel gently and watch the gap between the rim and a fixed point.
- Brake blocks or a fixed reference. Watch the rim against the brake pads on a rim-brake bike, or the fork or frame on any bike. If the gap shrinks and grows as the wheel turns, the rim is moving side to side.
- Sideways wobble. A wobble that appears once per turn suggests a bend or dent in one spot. A more general, gentle wobble can suggest uneven spoke tension.
- Up-and-down hop. If the rim seems to rise and fall as it turns, the wheel may be out of round. Also check that the tyre is seated evenly, since a badly seated tyre can look like a hop.
- Rubbing. Rubbing at one point on every turn can mean a locally bent rim. Rubbing that comes and goes is worth following up too.
Do not diagnose by ear or feel alone while riding. If the wheel wobbles so much that it rubs hard or the bike feels unstable, stop riding it and have it looked at.
Checking the spokes
Spokes are easy to check by sight and touch.
- Look for breaks or cracks. A missing, broken or visibly bent spoke is a clear problem. Check around the hub flange and the rim, because that is where spokes often fail.
- Squeeze pairs gently. Hold two neighbouring spokes and press them together lightly. They should feel similarly firm. A loose one feels noticeably slack compared with its neighbours.
- Pluck test. Some riders gently tap or pluck spokes and listen. They should sound broadly similar, and a dull or very different sound may indicate a loose one. This is only a rough guide, not a measurement.
- Look for movement. Spokes that rattle, twist or move easily where they cross are a sign of low tension.
- Check the nipples. These are the small fittings where spokes join the rim. Look for corrosion, rounded heads or signs of damage.
If you hear a pinging or clicking sound from the wheel while riding, particularly under load, it can mean spokes are settling or loose. That is another reason to get it checked.
Looking at the rim
Look all round the rim for:
- Dents or flat spots, often caused by potholes, kerbs or hard landings.
- Cracks, particularly around spoke holes. A cracked rim should not be ridden.
- Worn braking surfaces on rim-brake wheels, which can look scored, shiny and thin.
- Sharp or damaged edges that could cut a tube.
Bearings and axle play
A wheel can be perfectly true and still feel poor if the bearings are worn or loose. Hold the bike steady and try rocking the wheel side to side at the rim. A small amount of knock or clunk may mean play in the hub bearings. Spin the wheel and listen: grinding, roughness or a very short spin can indicate worn or dry bearings. Hub adjustment and bearing replacement are shop tasks for most riders.
Why truing is usually a shop job
Truing involves turning the spoke nipples by small amounts, checking the wheel on a truing stand, and balancing sideways movement against roundness and overall tension. Adjusting the wrong spoke, or turning too far, can make the wheel worse or damage it. Overtightening can also lead to broken spokes or a cracked rim.
A spoke key is a cheap tool, and some riders learn basic truing with a mentor and a spare wheel. But for the wheel you depend on, especially on a bike used for commuting, loaded riding or riding over rough ground, a shop is usually the safer choice. A mechanic may also tell you if the rim is too damaged to be worth saving.
When to get help promptly
Take the bike to a shop soon if you notice:
- A broken spoke or several loose ones.
- A wobble that rubs the brakes or the frame.
- A dent or crack in the rim.
- A wheel that has been knocked in a crash, even if the damage is not obvious. Include wheels in any post-crash bike check.
- Grinding or play at the hub.
Habits that help wheels last
- Look where you ride and avoid potholes and kerbs where possible, since these are a common cause of bent rims. Learning to read the road helps a lot.
- Keep tyres sensibly inflated within the range printed on the sidewall. Underinflated tyres make rim damage more likely over rough ground.
- Be gentle with wheels if you carry heavy loads or ride on cobbled streets or rough tracks.
- Include a wheel check whenever you wash the bike.
Wheels are central to safe riding. If you are unsure whether yours is straight and secure, a shop can usually tell you in a few minutes.