To be honest, when I asked a tire fitter I knew about balancing, I expected to get something very standard in response, but with some details I didn’t know before. But it didn’t work out that way in life, and I got a total of a little over an hour of voicemails in return messages on messenger. Maybe a little less than an hour if you remove the unprinted language (the reason for which I’ll give below), but still a lot. So I decided there would be two pieces. One – just about balancing (which I happen to know only superficially), the second – about how to distinguish in a tire fitting normal master from the crooked ghoul and extortionist money.
Why do we need balancing?
Balancing is necessary to save three things: money, safety and comfort. Money is taking care of the running gear. There is no mechanism in nature that would benefit from extra vibration. There are enough parts in the chassis that do not like unnecessary rhythmic shocks, even if not very strong. These are hub bearings, silent blocks, and ball-bearings. Besides, the tire itself wears out quickly. So, the balancing is the evident demonstration of care of these elements, and hence of means for their premature replacement.
As for safety, it’s simple, too. Think of what happens to a phone that’s just lying on the table. Nothing happens to it. But if you call it, it will vibrate and start crawling on the table. It just doesn’t have enough grip on the table surface. The situation is the same with an unbalanced wheel: it bounces on the road, an even contact patch is out of the question, the grip deteriorates rapidly. It smells of latent suicide, though many people don’t even think about it.
And the last one – comfort. Everything is clear here also: bumping and a steering wheel jumping in hands – it is very straining. One should be too quiet person not to pay attention to it. True, lack of balance is not felt in all cars, so if there is no shaking, it does not mean, that everything is all right with wheels. A shaking steering wheel is the extreme degree of careless attitude to balancing, and it is better not to lead to this situation.
What is the engine, what is the wheel?
The question arises: when it is necessary to do balancing? Is it before the beginning of wheel beating? Strangely, but yes. There are several situations in which balancing is necessary.
The first is the assembly of a new wheel. Every wheel that is just assembled needs to be balanced. This is obvious. The second situation involves seasonal “re-shoeing.” If the wheels have been stored assembled, they also need to be checked for balance. Sometimes balancing is not required, but more often you have to do it.
Thus, obvious situations come to the end, and not so obvious, but not less vital ones begin.
Strange as it may seem, very often a wheel with a new tire has to be balanced twice. The first time – during the assembly of the wheel, the second time – after the run-in. The thing is, the tire can lose its round shape during storage. A slightly “squared off” tire is put on the rim, balancing, but over time, the tire returns to its shape. Sometimes the balance stays the same after that, sometimes not. It is therefore recommended that a wheel with a new tire be re-balanced, with a recommended mileage of 1,000 kilometers.
Now let’s move on to the mileage. It turns out that wheels need to be checked every service. They do not think about it for some reason, but it is better to check the balance simultaneously with maintenance. You changed the oil – check the wheels. And 10 thousand kilometers is not that little, if the car has to go along the broken Russian roads.
Fifth reason to go for balancing is those very broken roads. More precisely, potholes. It is very desirable to follow the rule: if you ran into a pothole – go for balancing. The driver may forget about the hole the next day, but the wheel will remember it for a long time. It may happen that balance is not changed, but it does not hurt to check the wheel. At least for the reason that, for example, it is difficult to bend a cast disk from outside, but from inside – like two fingers on the asphalt. And this moment is necessary to control.
In general, it is better to be reinsured. There is no unnecessary attention.
For the sake of interest: is it possible not to balance wheels at all? We do not consider a situation with congenital idiocy. There is only one possibility to forget about balancing: to drive at a speed no more than 40 km/hour. It is considered, that at such speed the balancing is not necessary.
With what and how?
Now let’s get to the fun part: how balancing is done and what is often done wrong.
Captain Hindsight tells us: the wheels are balanced on a balancing machine. The cost of the machine may vary: you can buy a piece of junk for 10 thousand rubles, or you can get a top-of-the-line Hofmann for 1.4 million. But in general, many people do not like to skimp on the balancing machine: the client does not really care how and what he put the tire on the disc, and a shoal he can easily notice the balance. That is why the balancing machines are usually top-notch, and the rest of the equipment is simpler.
Note how the craftsman will center the wheel on the machine. By the way he does it, you can estimate the radius of curvature of his hands. There are three ways in total. The first is the easiest and most undesirable. In this case, the cone that goes into the center hole of the disc is mounted on the outside of the disc. That is, the wheel is hung on the machine shaft, then the cone is put on, then it is pressed with a nut. For alloy wheels, this is the most undesirable way of centering. The fact is that on the outside this disk is simply cast, but on the inside it is milled. And the inside of the center hole is noticeably more accurate than the outside. Therefore, it is better to put the cast disc differently: the cone should fix the inner part. In this case the sequence of positioning on the machine would be as follows: cone is put on the shaft, then – the wheel, and already it is pressed to the faceplate by the plate. By the way, for stamping, both methods will be normal: with the accuracy of die making “plus or minus a streetcar stop” the side of the taper application does not matter at all.
What does it depend on, what method will the craftsman choose? It’s up to the craftsman himself. Any machine allows you to center the wheel in both ways. But the first one takes less effort, and the lazy person will choose it. Also, it is possible to lose some parts, without which the second method cannot be used. It also happens, and it is a sign of a very mediocre “tire”.
There is another way of balancing – with the help of a flange adapter. This method was invented at Haweka (which is where modern balancing was invented). The method is based on the fact that the wheel is centered on the hub not by the center hole, as many people think, but by the tapered (or spherical) nuts or bolts. Here you put the taper on the machine shaft first, then the wheel, and then a flange adapter that centers the wheel with the mounting holes. In this case, the alignment is perfect: the wheel sits exactly the same as on the hub. But the method has a slight drawback: it is labor-intensive, takes more time, and balancing with an adapter costs about 30 percent more than balancing with the first two methods.
And finally, the most fantastic method. Not a cone is placed on the shaft, but a sleeve for the diameter of the center hole of the disk. The disc itself is clamped not with a cone, but with a flange adapter. This is the most precise and complicated method. They say it is used in a parallel universe by sober and clean-shaven tire fitters in white gloves. In our life, alas, it is not met.
Consumables for balancing are weights in the first place. They may be packed (spring) and self-glued (adhesive). Which is better? Both have their advantages and disadvantages.
Stuffed weights are attached closer to the edge of the rim, and they are more accurate. And because they are mechanically attached, they stick better to the rim. These weights are good where durability, not aesthetics, is needed. For example, on off-road vehicles. There are disadvantages to padded weights, too. First, they are not very beautiful. Secondly, the spring of such a weight is between the disk and the tire, and if the disk is old, the air will go in this place. However, if the tire and rims are weeded by the spring, soon they will start to weed everywhere. That’s the disc’s problem (its corrosion), not the weight.
Self-adhesive weights – adhesive weights – also do not fall off the disc, although it is easier to tear them off if you want to. And Chinese weights sometimes fall off by themselves. But they do not spoil the appearance of the disk.
What if he cheats?
I’ll tell you about how to tell the difference between a normal master and a charlatan next time. It is very interesting, but very long. For now, we’ll just have to see how a specialist will balance wheels and how a low-skilled crook (for simplicity, let’s just call him a “ghoul”) will do it.
A good professional will never balance a dirty wheel. Firstly, the weight of the wheel is important for balancing, not the dirt, secondly, a clean wheel is easier to wipe with solvent before sticking the weight, and thirdly, it’s just more pleasant to work this way. If the tire shop does not have a wheel wash, it is better not to balance anything there.
You have to balance a flat tire. A ghoul does not know that and does not check the geometry of the disc and the tire itself before balancing. A good mechanic will check them, and if it turns out that the rim is crooked, he’ll offer to straighten it out first. And if the new tire is crooked, return it to the store. Also a good specialist will first check the rim on the machine, and then – the wheel as a whole, so as not to bother the tire unnecessarily when mounting it. It is especially important for tires with a low profile.
The ghoul rips the scotch from the old weights off the disk with a knife. Usually along with the paint. A good technician would do it with a special plastic spatula, or with a drill bit (a circle for removing stickers).
The ghoul will bounce around the machine for a very long time. Most likely the reason for his dancing is an uncalibrated machine. A normal mechanic on a well-maintained and serviceable machine will balance a tire in about a minute.
Before installing the wheel on the hub, a specialist will check the adjacent surfaces. No dirt can be there. By the way, a little note to fans of painting brake drums on their VAZ: the paint from the drum falls off (yes, yes, this “high-temperature” – too), and the wheel begins to dangle. With wheels like that, you might as well go for a Darwin Award.
The ghoul, of course, will not check anything: he will remove the wheel from the machine and bolt it to the dirty hub. And he will also tighten the nuts (or bolts) with a wrench with a wild torque. And since the wheel is centered by the nuts, what will happen to the balancing after such installation is a mystery. A normal master will use a warm bulb torque wrench to pull it through.
One last thing: a good specialist will balance anything that has a center hole (and sometimes not even a center hole, as on some Peugeots and Citroëns). The phrase “but the wheel is not balanced” is uttered only by a ghoul. By the way, there were cases, when an old bucket and a stool were balanced for fun. Humor, of course, specific, but that’s how it is.
Also, the words “tire, sixteenth radius, cylinder, stingray and nipple” refer to the lexicon of ghouls. But we’ll talk about that next time, as we agreed.