Photo: Wheel balancing (Getty Images) Author: Konstantin Shirokun
This procedure would not bother any Ukrainian driver if it did not delay the queue at the tire shop during seasonal tire changes for our cars. Meanwhile, an unbalanced wheel promises us more serious problems, which car owners often do not even suspect.
Read about what unbalanced wheels can do in the RBC-Ukraine article.
When a wheel rotates around its axis, it experiences loads caused by the difference in its mass on either side of the axis. This is the so-called imbalance, and it eventually causes vibrations of the wheel, the chassis, and then individual parts of the car with which it “catches resonance.” Therefore, when we want the wheel to rotate the way the engineers intended, the imbalance must be eliminated. That is, to make it so that every two conventional parts of the wheel on either side of the axis weigh the same.
Why do you need to balance your wheels?
A car wheel has several components: a stamped or cast disk, a tire, a valve for pumping, and sometimes there is also a tube. Even during production, they try to make each of these components balanced on their own. It is impossible to do this perfectly in mass production, so the wheel after assembly is not ideal from this point of view. And we should also add an unfortunate coincidence, when the mutual arrangement of the unbalanced zones and the valve are maximally unfavorable, and this further worsens the balancing of the entire wheel.
Thus, a car wheel is almost never completely balanced, which is why the driver has to look for a workshop with a balancing machine.
Where does wheel imbalance come from?
If the wheel is not new, an even greater imbalance is added by a dented disk on a pothole, a lost balancing weight, an unevenly worn tire, etc. Finally, there are two types of imbalance – static and dynamic, but the driver does not care which one dominates, because the wheel and along with it half the car vibrate equally unpleasantly.
And the solution in any case is the same – all imbalances and vibrations are dealt with using a balancing machine and lead weights, which are installed exactly in the right place on the disk.
Why is it bad when the wheels are not balanced?
Why is it bad if at least one wheel of the car is unbalanced? It is harmful, especially for modern models with their high speeds and a large number of hinges and elastic parts in the wheel suspension.
Wheel vibrations are transmitted to other parts, and a considerable number of them wear out quickly: tire tread, chassis joints, steering joints, and even the steering mechanism itself – the so-called rack or gearbox. Sometimes, the hub bearing and wheel shock absorber suffer from micro-vibrations.
Drivers most often feel vibrations of a problematic wheel at a speed of about 60 km/h, and – as they accelerate – at about 90 – 120 km/h. When one of the front wheels is inadequate, a small tremor is felt directly on the steering wheel. If the rear wheel is unbalanced, the steering wheel will not shake noticeably, but there will be that same light hum and small vibrations of the body. Keep in mind that in many cases an unbalanced wheel finds an “accomplice” in the form of a poorly secured trim part in the interior. And then the wheel vibrates in unison with the plastic trim, wire harnesses under the dashboard or lock rods inside the doors.
How often should wheels be balanced?
It is advisable to check wheel balancing twice a year. Actually, this is what happens to motorists whose second set of tires does not have their own disks and is replaced on the same disks every season when changing wheels. But for those who have both sets on separate disks, it would be advisable to schedule the check to coincide with the seasonal change of tires. For example, having removed winter wheels in the spring, on the way to their storage place, it is high time to visit a workshop with a balancing machine.
Tire engineers also advise balancing new tires on rims not only immediately after purchase and installation, but also after the first thousand kilometers of mileage – when the tire frame, as they say, “breaks in.”
In brief
If all the wheels of the car were in perfect order a minute ago, and now there are signs of imbalance, the driver should perceive this as an alarm signal. Unexpected symptoms may indicate that a problem is brewing in the wheel. For example, a tire whose frame has finally torn, damaged once by a large pothole, may become unbalanced without warning. And this means that less than a minute remains before its complete destruction.
A wheel behaves in a similar way when the pressure in it just suddenly drops, or, say, there is a problem with the hub bearing or the adjacent ball joint of the suspension – and these are also problems that are very dangerous while driving. In short, your wheels should always be balanced and properly inflated so that against the background of their ideal condition you can easily notice some unexpected problem.
Materials from Nokian Tyres and Rosava were used in preparing this article .
Let us recall that RBC-Ukraine recently reported what is better for a car: a canopy, a garage or a parking lot.