Well Larry, let me know what you find out in practice on your balancer - especially what it tells you with a dynamic solution vs. a static solution.

I can tell for sure that the static solution is correct, because the bearings are so smooth that the vertical mounting of the wheel causes the heavy spot to "seek" the bottom. Slowly back and forth until its down. Then I mark it, and do a static solution. Bingo - it says to put the weights directly opposite the heavy spot, as you would expect. (Of course in a static solution its equal sized weights, 1/2 of the solution, on the inner and outer rim edges.)

In finding a dynamic solution, I was a little concerned because after "light tacking" on the weights and confirming the solution, the static solution is off a bit. But I don't remember how much - not much at all I don't think.

So, its more time with the machine for experimentation. The other thing that is perplexing is getting a different solution when the wheel is turned 90 degrees or so on the spindle. Don't understand that one at all. The manual talks about "rotational error" between solutions 180 degrees apart - but it doesn't explain how to work them out.

I'm simple minded and I feel that if a wheel/tire is balanced, it should show a balanced condition no matter how its placed on the balancer (rotational orientation). If not, then there must be a nearly infinite number of possible weight/location balance solutions.

Oh well, such is the learning process. The Snap-On does have a self-calibration procedure that I haven't been able to get to work - hopefully its just because I don't have the required 3-oz calibration weight.

Did you get a manual with yours?

Ken300D

My buddy who heads up quality control for Mitsubishi Motors U.S.A. tells me that a good way to confirm a proper tire balance is to rotate the balanced wheel 90 degrees on the machine and re-run it. It should remain balanced.

He also says that you can balance many items on these machines. If you take an egg shaped wheel, if you apply enough weights, you can get it to balance. But if you mount this on your car, you couldn't drive, because egg-shaped objects aren't round.

Anyways, it's an interesting concept.

__________________
Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".

allen,

What on car balancer does your shop use? I can't remember the last time I saw a tire balanced on the vehicle. Many years ago, before the "computer balancer" revolution, the Hunter and Bear were the ones I saw used. At that time the only alternative was a bubble balancer. I expect the ones they use now are the same principle, if not the same machines that were used then.

I believe if it is necessary to use one of these to get a good balance, you probably have a heavily out of balance rotor, hub or something. If it is necessary to do this, it would be nice if there were some way to spin the rotor to check its balance.

Have a great day,

that the regular size stuff with 60 or 65 aspect ratio tires can run just fine off the car. But I routinely run 18 and occasionally a 19 or 20" setup, and this big stuff just doesn't want to co-operate unless it's done on car. Additionally, most of this stuff is done on new or 2/3k mile cars, so while there could be an anomaly, it's unlikely on a new Benz, BMW, or Porsche. Oh, forgot to answer your question. They use the old style lawn mower spinner motor at one shop I go to, with a human behind the wheel. The other shop uses the newest Hunter, which frankly does not give as true a ride as the guys doing it the old fashioned way. Kinda puts more credence in the operator theory!

just a couple of things
- on the hunter 9700 it will actually tell you if it can't balance a wheel tire. i've seen 17" 45 series setups that had a dent in the wheel that have been rejected by the machine. also, you're supposed to match the wheel & tire high & low points to get the best possible setup. it is pretty smart but as other posters have indicated, the operator has a lot to do with it. some of them won't bother to do the wheel tire matching process at all and just run the machine as is.
- there was another thread sometime back that talked about positioning the weights in the wheel to get the best possible balance, i'd have to look for it but i seem to recall something about placing the weights as close to the center as possible(?)

__________________
joE
1993 300e-2.8 - gone now <sigh>
"Do not adjust your mind, it's reality that's malfunctioning"
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The customer service group at Hunter is very good. They emailed me operators and calibration manuals for my new (to me) wheel balancer. I was amazed at the features on this machine.

First of all, I can set for grams or ounces and I can set it to give exact weight rather than rounding off to 1/4 ounce increments, or 5 gram increments. Also, it has a match mount mode that leads you through balancing the wheel alone, marking it, mounting the tire, rebalancing with tire, marking the tire, then turning the tire to best match the wheel before the balance weight application.

I read some years ago when the new car manufacturers started doing this. I didn't know that some of these computer balancers lead you through this procedure. By matching up the tires balance with the wheels balance, you ultimately will add less weight and get a better balance.

I expect you could accomplish this by thinking it through, but having the machine lead you through it seems like a nice feature.

Ken, I would be interested in knowing if your Snap On has this mode. If you don't have a manual, it may have it, but you have no way of knowing. It is a combination of moving switches to a certain position at a certain time, there is no switch marked match mode. If you don't have a manual, it would be worth contacting Snap On to see if you could get one.

I am really anxious to get back from Europe and pick up my balancer. My 300E really needs the wheels and tires smoothed out.

Have a great day,

Well, the whole two weeks I was in Europe, I was thinking about getting my wheel balancer when I got home. I finally got it and brought it home today.

It turned out that the Hunter 700 that I agreed to buy would not check out properly. The guy gave me a Coats 1001 for the same price. I like it better. It has a MAG function which allows me to tape the weights hidden inside the wheel with less fuss than using an older balancer without this feature.

I got it home, got it hooked up and hastily DYNAMICALLY balanced all four wheels on the 300E. I took it up the road and hit 100 MPH and it was as smooth as silk.

Many of these tire stores static balance aluminum wheels because people complain about the ugly weight on the outside. You can tape weight them and have no vibration. Static balance usually makes them worse because you are making the dynamic balance worse by adding weight only to one side.

It is very simple to use one of these machines, put weights where it says and you're done. I am quite confident that in 30 minutes I could teach any high school kid how to use one of these machines properly, but almost every tire store insists on doing a static balance. I had to buy one of these expensive machines to keep from having a fight every time I buy tires.

I am now going to try to remember to see if the heavy spot goes to the bottom like it does on Kens machine.

What a great invention.

Have a great day,

Yes, just as Ken said, the heavy spot goes to the bottom, and doing a static balance calls for a weight opposite the point that went to the bottom on its own.

I rotated and balanced the wheels on my wifes four runner today and found that the tire store had them nowhere close to proper balance. It now goes down the road smooth as well.

I'm very excited about the addition of this machine to my shop. It allows me to have properly balanced tires and wheels on everything. Running around with imbalanced wheels is annoying, but worse yet is hard on suspension components and shocks.

Have a great day,

I've been racing for 22 years IMSA. The only way to balance a tire properly is on the car, PERIOD (first you use a road weight balancer to index against the wheel). Hunter makes a on car balancing unit that spins the tire to 140 mph. There's a race version that spins to 220 mph but that's a waste of money to take care of a road car.

In most major cities there's a specialty shop that does on car balancing. Wouldn't suggest doing this yourself as you need a lift and two people to align resting racks under axles.

I agree that it makes all the sense in the world that the ultimate balance is to balance the ENTIRE rotating assembly together. It makes perfect sense. However, the drum/rotor/hub are usually pretty close to proper balance unless there is something seriously wrong. Additionally, any drum/rotor/hub imbalance is at a smaller radius having less effect.

So, the PRACTICAL method for a street car is for the wheel/tire to be PROPERLY, DYNAMICALLY balanced. For most street applications this works quite well.

The problem that is imposed very often by the tire stores is that they do NOT PROPERLY balance the wheel/tire. The tire store justifies using the static balance feature on their expensive balancer by saying that "most customers don't want the ugly weights to show on the outside of their alloy wheels. If they are going to use the static balance on their computer balancer, they could use a bubble balancer and do just as good(bad?).

Even if they do use weights inside and out, they often don't spin the wheel AFTER applying the weigths to see that it is right. Furthermore, they don't occasionally check their balancer for accuracy.

I'm sure there are a few tire stores who do a great job at balancing wheels, I just haven't come across one of them yet.

Have a great day,

Next Purchase: Tire Changing Machine




Ken300D

Ken,

That's exactly what's on my mind. I do not foresee, however, buying a rim clamp machine. There are Teflon, or some such material, covers for the tools on a center post machine. If you are careful and use these accessories, you can use a center post machine without damaging wheels. Damage usually comes from a careless operator swinging the center post tools around and banging into everything in sight. If you are careful with the tools, even without the protection covers on the tools, you can change a wheel with only a slight scratch around the very outside of the rim, almost unnoticable. WITH the protective covers, you can even eliminate this slight scratch.

The center post machines are being obsoleted by the rim clamps, so I expect to see more and more of them on the used market.

Good luck,

Well, I got a tire changing machine of sorts. I found an old manual tire changing machine from the sixties. The kind that you lag to the concrete and use a bar to remove the tire. EXCEPT, this one has an air powered bead breaker! This powered bead breaker takes care of the toughest part of manual tire changing.

I found the machine at a flea market for $50 and got to see it break the bead on the spare from my pickup before I bought it. The challenge was that it is for narrow tires/wheels. I looked it over and figured I could modify it for wider wheels. By cutting a piece of structural pipe on the bead breaker, welding a pipe that fit over the original pipe, then drilling some holes for a pin, I made the bead breaker adjustable for any wheel size up to about 10" wide. The thread on the taper nut threads over "knots" on the center shaft. By welding some spots on the shaft, then cutting them to size, I was able to extend the useful length of the shaft to fit the wider wheels.

The bar end is shaped like the knob of a baseball bat. It didn't visibly scratch the wheels. I am going to try to figure out how to put some hard plastic of some sort over it to eliminate scratching altogether. I have not figured this one out yet.

I finished the modification last night and changed some of the tires on my daughters car. I tried it on the 7" wide spare from my 300E and it worked for that as well. This was without it lagged down yet. Once it is lagged down, I expect it to be very easy to use.

I am going to pour a small pad behind my shop where I can mount it outside and out of sight.

It's not a fancy rim clamp machine, but I now am able to declare my independence from the tire store.

Have a great day,

That's great - you can get a wide selection of tires now from anywhere in the world, mailed to your door.

Balancing tires seems to be a task with little chance of a real personal injury, plus I understand how it is done.

Changing auto tires is more of a mystery to me. Sure, I've changed bicycle tires as a kid, even motorcycle tires. But now we're talking tubeless tires with a steel cord in the bead.

I understand breaking the bead loose from the rim. How do you then get the old tire off the rim?

Then, I assume you reverse whatever mystical procedure to get the new tire onto the rim. How do you set the bead in place on a tubeless tire?

Fortunately, just about any place you get tires mounts them for free. They get their money on balancing and valve stems.

About a week ago I got a quote by phone from a tire shop for some Cooper tires for my small pickup (I've found Cooper to be a good, long-wearing tire at a good price.) The first quotation was of course fully balanced with new stems, so I advised that my old valve stems were fine and that I had a balancer - please take those items off. They had the quote printed up when I got there - I signed - and they took the loose wheels/tires.

When I picked them up, they had new valve stems and were balanced. So few people have a "no stems, no balancing" order that it doesn't get communicated well in the shop. So I got these things for free. (Haven't had time yet to check their balancing job.... )

Here's some good online info for Cooper Tires:
http://www.coopertires.com/tire/

You can see all the size, load and tread specs online.

Ken300D

Ken,

Your experience with the tire store not paying attention to your orders is the same type of experiences that have driven me to gathering up enough equipment to be tire store independent. It frustrates me to no end when I tell them how I want the tires balanced and almost EVERY time its as if I didn't even say anything about it.

There are some safety issues that need to be attended to when demounting/mounting tires. The biggest chance of safety problems is with 16" and 16.5" truck tires. I don't plan on messing with any of these. As long as you watch what you're doing and mount the right size tire on a rim in good condition, the process is safe. Tire explosions almost always occur when mounting a 16" tire on a 16.5" rim or vice versa. Also any other size, if rim and tire do not match.

Once the bead is broken, you merely put the tool between the tire and rim, put the other side of the tire, 180 degrees opposite in the smallest radius area of the rim and then move the tool around the rim until that bead comes off. Then you repeat for the other bead. Putting the tire ON the rim does not usually even require any tools if you lubricate the bead. After lubricating the bead, you can simply put one side of the bead into that smallest radius of the wheel and then start pushing the tire over the rim. Repeat this for the second bead and its on.

If the tire is the proper size for the wheel, then the bead will seat with no trouble. If you are timid about loud popping noises that sound like a pistol, you may not want to mount your own tires. When the bead "pops" in place it sounds like a pretty good size caliber pistol going off and you never know EXACTLY when it is going to happen. If you're shell shocked, it might not be a good thing for you to do.

You need not be intimidated by the process, but with anything you approach you should research the safety rules involved. On almost any tire or tire equipment website you will see a link to something called "R.I.M." This is a simple safety program that you can read and easily understand the safety steps involved in tire mounting. I have read them and have deduced that in almost all cases of tire explosion it has been due to someone not paying attention to what they are doing. Let's see..... the people at the tire store don't even pay attention to you when you tell them not to replace valve stems and balance your tires, maybe they pay that same amount of attention to the safety rules of their business. This is very sad.

You're right about getting the tires delivered to my door. I just ordered some tires for my 300E and got a GREAT deal from tire rack. The set I ordered was one size larger than my car usually takes and is an odd size. Because of the odd size, they evidentally are discontinuing or ceasing to stock. I got them for about 55% of the regular price. I don't pay tax because they're out of state, but I do pay shipping so this balances out. They appear in my driveway, dropped off by the UPS man, and I'm ready to do my thing WITH NO TIRE STORE HASSLES!!!!

I'm thoroughly enjoying my TIRE STORE INDEPENDENCE.

Have a great day,