Weights that are put on wheels when tires are balanced

Maintenance/Repairs
21

What and how much experience have any of you had with tire balancing?
Personally, I have never balanced a wheel and tire in my life. What I have done, as a physics student 35 to 40 years ago, is take undergraduate and graduate courses in the subject of mechanics which describes how solid bodies respond to applied forces. One example of this is how an out-of-balance wheel and tire behave when rotated and what must be done to bring them into balance.

the bubble never lies and if one knows how to separate the lead things will be fine
By “separate the lead”, I assume you mean how to divide up the correcting weight between the inside and outside. A bubble balancer is incapable of telling you how to do that. (That’s what I meant in the second paragraph of my 3:01 pm post.) Dynamic balancing is a three-dimensional problem. A bubble balancer can only give you two dimensions of the solution. It takes a dynamic balancer to get all three.

Do you think that if a computer balancer gives a reading of (example here) 1.25 ounces on the outside and 1.5 ounces on the inside that those figures are dead-on-the-money with no variation? Do you think if you tack on a 1.25 on one side and a 1.5 on the other, everything is then Nirvana?
If the balancer is malfunctioning or the operator is incompetent, you will get a bad result. However, in order to get a good balance, someone or something must answer three questions correctly – how much weight, where around the rim and which side. The complete solution may require a different weight on each side and they may not be next to each other.

22

I’ll throw out some things to think about here.
Some of you seem to be under the perception that a computer balancer is always Dead-on the money when that is not the case. They shake and also have a +/- tolerance in them. The computer balancer may get it close enough that most people don’t notice a slight vibration.
I notice these things because to be honest, I’m a nitpicking SOB, and not just on tire balancing. I’m the same way on engine performance, front end alignments, etc.

I absolutely hate balancing tires (most techs do) and only do it for myself, relatives, and friends anymore. I also cannot count how many new, just purchased tires I’ve rebalanced in which the car owner did not even notice the problem since it was so slight.

Another point and this in regards to steel wheels and/or wheel covers. Computer balancing does not balance those covers, but they can be balanced on a bubble balancer. Covers are often unbalanced and wire wheel covers are the worst of the lot.

I agree that a bubble balancer is “outdated”, but I assure you that used properly it is as accurate as the computer balancer. The simple fact that I’ve successfully rebalanced many new tires should prove that. The last ones were about 3 weeks ago in which 2 new tires were balanced twice at the tire store, finally taken to a gas station (where they spent almost 15 minutes on one tire in an attempt to get it on the money) and finally wound up with me. A couple of minutes and problem solved.
I’ve even thrown a few bubble balanced tires on the computer balancer a few times, “just to see” and it came up zeros so I must be close, huh? So the computer says.

I started balancing tires on bubble balancers while working at a gas station during my high school years and this was back in the 60s. Yes, I’ve balanced countless tires on Bear and Hunter machines with thankfully very few on a Snap-On so I like to think I know my way around the wheel balancing end of things.

JMHO, but real world practical experience trumps physics classes and opinions of people who have never balanced a tire in their life.
Did your physics classes take into account the valve stem, wheel cover imbalance, and tire thickness variations?

Dis me if you want, but it seems to me that before telling someone they’re wrong on a subject the person doing the correcting should have at least 10 minutes worth of real world time in on the subject about which they’re speaking.

23

Guess I should have asked. What is your opinion in regards to many tire stores placing the weights on one side of the wheel only?

24

One method of tire balancing that no one has mentioned is the old “as you drive method”. In this, one has an assortment of weights (in ones pocket), drives the vehicle, assesses wheel vibration, and adds, and positions weights as deemed necessary to obtain dynamic balance. It might not sound pretty, but, if it works…?

25

I don’t like those crimp on weights at all on clear coated, alloys. They tend to bite through the clearcoat and allow oxidation to start gaining a foot hold. Unfortunately, they are often applied by the OEM so the damage can already be done when you get the car. Regardless, I always ask for stick on weights whenever possible when rebalancing.

26

You’re really making a name for yourself in this community. With your snide comments and lack of real experience, it is clear that your comments are merely cut and pasted from the internet. Perhaps you should post anonymously?

27

I have ONE question for you OK…

With a bubble balancer…HOW do you determine which side to put the weights on??

And if there is no way of telling (which I find hard to believe that you can) and you put the weight on the inside…how does that NOT off balance the wheel from side to side???

28

It’s what I would call an “educated guess”. Generally a 60/40 split works fine with 60% of the weight on the inside and the remaining 40 on the outside.
It’s also easy, for me anyway, to figure out where to place the weights in relationship to the circumference of the wheel; e.g., an outside weight at one point and the inside weight say 10 degrees offset from that.
It’s all a matter of reading that bubble correctly.

I’m not ripping computer balancers up here as they’re generally close enough to satisfy everyone. (Other than that Snap-On boat anchor). I’m only pointing out that I’ve used my bubble balancer to correct countless new tires that were computer balanced and still have noticeable, and in some cases, not so perceptible shake.

In the small town where I live an older gentleman (now deceased) used to run a local gas station and used one of those old Micro bubble balancers. He told me once that he also rebalanced a lot of new tires under the same circumstances.

For the poster who thinks a physics lesson will balance a tire, I could ask this. I have a brand new set of 4 tires and 4 wheels (unmounted) to be used on a custom application.
If I provide all of the info including wheel/tire weight, width, diameter, wheel offset and backspacing, along with the minutae like valve stem weight, weight of the metal removed for the valve stem hole, etc. can you figure out how much weight will be required to balance it and how much will be needed on each side. I’ll even settle for “close enough”, say, a 1/4 ounce +/- on each side.
If you want the info, I’ll provide it, you give me the weight required info, and it will be mounted up, weight added, and see what happens on the balancer.
The tires/wheels need mounted anyway so it’s not a big deal.

29

A tire which is “stiffer” at one point along its circumference is equivalent to a tire that has a higher run-out at that point
Raymond, I see what you mean. That’s an interesting wrinkle. To cope with it, I would guess that the balancer introduces an imbalance to compensate for the pseudo run out. I cannot remember seeing a balancer that sophisticated in a tire store.

ok4450:

The last time I saw a bubble balancer used was in a small town, one man shop in the early 1970s. The balancer was essentially a two axis spirit level. The guy placed the wheel and tire on it then tried different amounts of weight at different positions around the rim until he found a weight and a position that centered the bubble. The balancer told him only two things – the total amount of weight required and where around the rim it had to go. The balancer would call it good whether he put all of the weight on the outside, all of it on the inside or divided it up somewhow. That’s the difference between static and dynamic balancing.

From the point of view of a physicist, a wheel and tire form a distributed mass. Details like valve stem, wheel cover imbalance and tire thickness variations are included, by definition. Raymond’s variations in side wall stiffness make it an elastically deformable distributed mass, which is a much harder problem. Before computers, one had to make simplifying assumptions so that it was humanly possible to perform the calculations. That’s no longer necessary.

30

It’s what I would call an “educated guess”. Generally a 60/40 split works fine with 60% of the weight on the inside and the remaining 40 on the outside.
It’s also easy, for me anyway, to figure out where to place the weights in relationship to the circumference of the wheel; e.g., an outside weight at one point and the inside weight say 10 degrees offset from that.
It’s all a matter of reading that bubble correctly.

Then you’ve ONLY balanced the tire in two dimensions. It MAY be fine…but it may NOT be.

31

It’s what I would call an “educated guess”. Generally a 60/40 split works fine with 60% of the weight on the inside and the remaining 40 on the outside. It’s also easy, for me anyway, to figure out where to place the weights in relationship to the circumference of the wheel; e.g., an outside weight at one point and the inside weight say 10 degrees offset from that.
Finally! The answer I’ve been fishing for. The point I have been trying to make from the beginning is that a bubble balancer is limited to static balancing. Without experience like yours, there is no way to extrapolate from there to a dynamic balance.

32

OK4450… Just more inexperienced idiots that don’t know a thing about auto repair. It’s like STAR commenting on automotive A/C. Off base and brainless.

They don’t have a clue so don’t bother with them.

Willey, logged off again.

33

Call it what you will - it works. Care to explain why the ones I rebalance on a bubble balancer come out “muy perfecto” after repeated attempts on a computer balancer fail?
Also, I do not simply split the weight and put it on directly opposing sides; there’s a bit more to it.

I’ll just throw something else out there for all of the experts who have yet to balance a tire in their lifetime.
Become buds with a guy at the tire shop and ask him to do something for you.
Have him balance a tire on a computer balancer using cones (most of them) and get it zeroed out.
At this point, the tire balance is perfect is it not? Continue.

Have him remove the tire from the balancer, get a cup of coffee, and then mount that same tire right back on the balancer and spin it up. Have him do this 10 times while you stand there with paper and pen in hand writing down the figures.

The odds are that you may (could be a stretch) get 5 of them that are zeroed out (perfect balance, correct?) and the other five will show varying degrees of imbalance.
So which figure are you going to use, or should you just average them out?
If the wheel assembly is in perfect balance on the first spin then it should remain the same on the next 9, huh?

Most of the time you don’t even have to remove the wheel/tire assembly. Just loosen the cone, retighten, and chances are your previously perfect balance has gone away.
Plates and collets are available now that IMPROVES the accuracy, but you could do the same thing with these. Loosen the wheel, rotate it on the plate, and now your balance may be gone again.

It appears that a number of you see a 4 or 5 grand computer balancer and automatically assume that it is spot-on, never-fail, and never needs calibration; while not being knowledgeable about that annoying little movement on the cones at all. We won’t even get into wheel distortion that can come into play in some cases.

I will say this. I’ll put that bubble balancer up against a computer balancer any day of the week and win. That’s not egotism on my part; it’s just a card carrying fact that has been proven repeatedly.

I still would like to know if the physics guy would like to chart a new tire and wheel assembly as they mentioned having done in class. They can use the tire/wheel data I provide, figure it out on paper, give me the weights, and I’ll see what happens. Heck, I even offered them a 1/4 ounce of fudge on each side. :slight_smile:

34

There has been a lot of discussion in this thread about the relative value of knowledge/theory (eg physics) vs hands-on experience. I have lots of both, although I have been out of day-to-day auto repair for a while.

With all that, I definitely put a lot more value in what mechanics are experiencing on the day-to-day front lines over the theory I learned in school. And yes, when the real life experience doesn’t match the theory, I do try and figure out what else might be at play to cause the two to not align.

Being able to question and challenge real life experiences vs theory is always healthy. Debating the two often gets us to answers that are not possible when focusing on one alone. It can fall apart, however, when the attacking begins. Let’s do what we can to keep respecting all the different backgrounds that make this board the goldmine that it is.

Joe

35

Being ripped a bit does not irritate me at all. Matter of fact, the only posts that even bug me at all are Star’s posts about automotive A/C and only because they’re so far out there and potentially damaging to both vehicle and owner, both financially and physically.

The basic problem here is that some assume that because a balancer is “computer controlled” and “costs 4 to 5 grand” that it is always dead-on and there is never a variation.
I would actually buy a ticket to watch some of you attempting to balance a tire on that new Snap-On unit we bought at one time.

Those who have watched their tires being balanced could consider something I mentioned in regards to cones and wheel centerbores.
Did the guy who did the balancing throw the wheel onto the balancer, insert a small tapered cone fitting against the wheel, and then balance the tire? If so, read on…

Here’s a comment from a wheel balancing site for those who choose not to believe me.

Rebalance Your Balancer
One way to improve balancing accuracy and repeatability is to use precision machined flange plate lug adapters instead of centering cones. Flange plate adapters center the wheel on its lug holes rather than the center hole. Lug adapters are expensive, but eliminate many of the mounting problems associated with cones.

Also, for those who choose to bash me a bit about the bubble balancer I will add that I do NOT use a wheel centerbore or the cone on the balancer when balancing a wheel. I have the lug adapter that is mentioned and it helps tremendously.

36

A really accurate computerized wheel balancer
will indicate the need for weights on either
the inside or the outside or both the inside
and the outside

37

Two ‘scientists’ did research on this sort of thing. They issued a report called something like “Dunning-Kruger effect” It is worth googling for.

38

You’re correct, to a point. You’re assuming the computer balancer is dead on when new and remains so after 5 years of use. You’re also not taking into account things that I have mentioned several times already.

A few snippets from other websites:
The way that a wheel is mounted on a balancer will not only affect the accuracy of the balance job itself but also the repeatability of the balancing results. Worn mounting cones or shaft bearings are sometimes the problem. Using the wrong type of cone can also give inaccurate results. So too can dirt on the wheel or nicks in the wheel center hole. But another often overlooked cause is using the wrong mounting technique for the type of wheel.

The basic idea is to mount the wheel on the balancer the same way it is mounted on the vehicle. A pilot hole centric wheel (one where the center hole positions the wheel on the hub and prevents it from wobbling sideways when the lug nuts are removed) can be mounted on a balancer with a cone from the backside. But a lug centric wheel (one that does have some sideways movement when the lug nuts are removed) requires a different balancer mounting procedure. A lug centric wheel should be mounted with a cone from the backside and an adapter flange plate against the front side. The fingers on the flange plate must be properly positioned so they line up with the lug holes in the wheel. This is necessary to center the wheel on the WHEEL balancer shaft. If this is not done, the results will not be 100 percent accurate or repeatable.

Precision flange plate adapters are expensive and may only be offered as an extra cost option with a new wheel balancer. A set of flange plate adapters that covers most vehicle applications may run from $1300 up to almost $2000 depending on what you buy. But the improvement in balancing accuracy and repeatability can be well worth the investment. They can also prevent unnecessary comebacks and dissatisfied customers.

Yet another. (Note the .25 ounce residual.)Thanks to technology, we now have adapters for specialized assemblies, the ability to reduce the correction plane interference ratio for a particular tire/wheel assembly and minimum accuracy standards of 0.25 ounces residual imbalance when a satisfactory balance has been indicated.

Continuing, and in a motorcycle vein. Been there, done that.
Then, I put on the new tire (takes about ten minutes, max), and take the wheel to the corner filling station to set the bead. Pop, Pop. Then I reinstall the bearings, (I replace the bearings every other tire change-- I get double sealed bearings fairly cheap at a bearing house), and balance the wheel. To balance it I just hang the axle between a couple of chairs and spin the wheel. (I bought a large box of stick-on weights a few years ago, and that’s last me for twenty years). That gets the balancing accurate enough that I can notice the difference in how much duct-tape I use to hold the trial weight on. In fact, I’ve had a computer spin balance done before, and taken it home and used my chair method and found them several grams off. A computer spin balancer isn’t more accurate, it’s just faster and easier.

Bearing balancing like that is also a REAL good measure of how good your bearings are. And you can throw a dial-guage on the setup to check wheel and disk runout while you’re there. Tell me a shop does THAT.

I’ll mention this again. For those of you who watched your wheels being balanced and saw all zeros come up denoting a “perfect” balance; was the shop using cones on the wheel centerbores?

39

I recall driving off after getting new tires, and the tires were horribly out of balance. After returning back to the shop the tech insisted they were balanced correctly. He put them back on the spin balancer and spun them back up, the machine came up that they were balanced. so I asked if he could spin them up on there other balancer on the other side of the shop. He grudgingly did, and guess what the wheel was so out of balance on that machine he had to remove all the weights and start completely over on all wheels. After that they where better but still not up to my satisfaction, so I took the car to a different shop ask if he could check the wheel balance. Guess what, they were out of balance. They Had to rip all the weights off again, and start over. This time wheels balanced good. So three machines, three totally different reading, and only one was accurate.

My conclusion is a spin balancer out of calibration will give you consistently out of balance tires.
A calibrated one is more accurate then a bubble balancer, however a bubble balancer will never go out of calibration and can always be trusted within it designed tolerance.

40

I buy most of my tires at a farm supply store about 25 miles away and the drive home gives me an opportunity to “see how good they done”. Without fail, I always have to pull one or more wheels off and rebalance them on my bubble balancer.
Some of the guys in the tire shop are personal, lifelong friends and I know them to be as professional and accurate as possible, but they have no control over a digital readout.

Note the one site makes reference to having a residual 1/4 ounce imbalance even when showing a perfect balance.

What some of you who do not buy into the bubble balancer method should do is this, especially if the shop uses wheel cones.
Have the guy spin a wheel up while you watch. Note that the weights are applied correctly, the wheel is spun up, and “perfect balance” is verified.
WITHOUT loosening the wheel cone, raise the wheel shroud, open your palm, and sharply hit the side of the tire with the heel of your palm.
Lower shroud, spin it up, and see if you still get a perfect reading. Odds are you’re going to see a different set of numbers.

For what it’s worth I’ve done countless wheel balancing jobs on bubble balancers, strobe balancers, and 3 or 4 types of computer balancers. Also, like most mechanics, I despise working with tires and exhaust systems. It’s easier to farm this garbage out.