Balancing Bias Tires/Split Rims (coined)

[The_Handier_Man1]

From: ClydesdaleKevin
Sent: 8/31/2005 11:07 PM

Just a word about the necessity of balancing our bias ply split 17.5 rims...I was told by a very knowledgable and VERY old tire man, who has owned the same shop for decades, that balancing our wheels is a waste of money...lol.  Our rigs are so heavy, and we are so isolated from the wheels, that you wouldn't notice any difference in ride, performance, or longevity between a balanced and an unbalanced wheel.  To quote, "IF you feel an anomaly, it is NOT going to be the balance of your tires.  If you can feel it, its something major like kingpins or alignment, or even loose lugs."  He went on to say that the only 17 bias tires that one should consider balancing MIGHT be the front tires, and even that is "useless as teets on a bull"....lol.  Besides, you are going to rotate them occasionally, so why bother balancing just the fronts?  As he said, don't bother balancing them at all.

That said, when we had our new tires put on, there was only one shop near us, Colony Tire in Elizabeth City, NC, that could get the tires and do the work.  Again, it was an older guy that owns the place, and he also told us that yes, they COULD balance the wheels, but since they were "truck" wheels and required a special balancing proceedure or machine (I forget exactly what he said), instead of the usual 6 bucks a wheel to balance them, it would be more like 25 bucks a wheel.  He also stated that, while it was up to us, he wouldn't bother...although he tried to talk us into balancing the front wheels "just in case."  We decided not to balance anything.  Our rig rides straight and true, the only thing you "feel" from the wheels is the familiar "thump thump thump" while the bias plies are warming up, there is absolutely no uneven wear, and you can take your hand off the wheel on a straight road, and she stays on the road.

Kev



From: denison
Sent: 9/1/2005 6:18 AM

My Winny has the 7.50-17 inch tires on 5 bolt split rims like Kevins Futura RV. The front wheels currently on the RV have no balance weights on them, and they run smoothly. I don’t know if they were ever balanced or not, since I got them 2nd-hand along with 5 more tires already mounted on wheels. All 5 of them came from the same Travco owner who had upgraded to 5 bolt 19.5 wheels.
If I did experience shimmy or wobble, getting the tires balanced would be one of my first actions.



From: Slantsixness
Sent: 9/1/2005 7:48 AM

"Balancing Truck tires is a waste of money and time"

NOT TRUE.

If your truck tires are not balanced, there are a variety of things that can occcur:

Premature wheel bearing failure
Premature wear of Steering components, including King Pins
Uneven tire wear, high speed traction problems. (Float-bounce at highway speeds)

You may not "feel" it, like you do in a car, but the vibrations are indeed still causing the wear.

This is true even more for bias tires, since they have a great deal of "road feel" in addition to Bias belts.

Now, with that said, I agree that most shops do not balance heavy truck tires. Largely this is due to how much more difficult it is to balance them. Ususally, it takes quite a bit of weight, and repetetive balancing to get them right, plus most shops don't have the necessary adapters for spin balancers and the large truck tires (coined rims, 5 and 6 lug Budd rims, etc.)

Not everything the older and seemingly knowledgeable mechanics say is necessarily to your benefit, rather it's to his benefit because he does know how much of a pain in the a__ it is to do the job properly, so he charges more, or recommends not to balance them at all.

The service manuals even outline the importance of proper wheel balancing, and the procedure, if it wasn't important, why would it be there? 

When it comes time to "balance" your tires, there are several ways to do it. The balancing bags (roll around inside your tires and settle where they are needed, or that's the theory...) the centrifigal backing plate (this gimmick works, but weakens the load carrying capacity...) Traditional bubble balancing (cheap, easy, but not the most accurate) and Spin Balancing the best method, and the hardest to get right. Most machines have to be calibrated for larger truck tires, and the correct adaptors must be used, or the balancing will be incorrect.

My 6 tires cost $5 each to balance, and the guys who did mine worked their buns off to get them balanced, so it would makes sense to me if it cost a little more. I tipped them $10, because they worked so hard and it was 95° that day, so instead of $30, it cost me $40, but my Winnie rides down the road like a new car (with bias ply tires).



From: Slantsixness
Sent: 8/29/2005 11:18 PM

There's something really important you need to know.

17.5" rims are "coined"

If the tire changers do not have the right adapters, specifically the one with the recesses for the coins, they will appear very badly bent on the balancing machine. Don't be fooled!

All six of mine were "bent" when the young guy started to balance them. Then the older fellow (shop owner, actually) came by and told him he was full of something I won't mention here, showed the tire tech how to use the adaptors, and Viola! all of my rims turned out to be within acceptable "roundness" with less than 15 oz of weight on all except one, which may be bent just a little, but it's on the rear, and you'll never feel it!

By the way, it is normal on dodge truck rims to have an "unsusually large amount" of balancing weights (some of my rims have 6 weights, some only two!

Tom



From: bboat101
Sent: 8/31/2005 4:51 PM

What do you mean by "coined"?
thanks
brian



From: cooneytunes
Sent: 9/1/2005 9:54 PM

Kev ......What Tom said is exactly on the money....Tires must be balanced.....but balancing larger truck tires has been a topic of conversation an research which has been on going for a long time....One of the problems with balancing using weights is that the weights have to be heavier than a car wheel weights. And the heavy ones like to get off somewhere along the highway. To solve this problem most trucking fleets and truck wheel places use what is called "Bean Bag Balancing"....I have two buses a 2000 International and a 1988 Ford,  both have 1100 x 22.5 tires, both have tires over 100K miles on them, both  balanced using bean bags...What the bean bags are,  a light weight plastic bag with ground up tupperware inside the bag..called balancing material placed
inside the tire when it is mounted on the rim.  As soon as you start driving, with-in a half mile the bags will break open, centrifical force will send the ground tupperware where it is needed, as the tire heats up it melts the tupperware and becomes part of the tire, inside the tire as  weight where needed. After you park some of it falls to the bottom of the tire and the process starts all over again, but will only take about 100 yards of driving to rebalance....this is good because as the tires wares
over time and driving, your wheel is balanced continuously, so until you change tires, you'll never need balancing. My rig's tires where balanced like this and it is as smooth as a car. For city driving in a large vehicle your guy there is right, the rears do not need it, but your fronts should still be balanced........your
speed
will very seldom get above 35 mph.....but any highway driving, all you wheels should be balanced, or a Tom elated too, things will vibrate loose and you may never feel it until it falls off...or breaks........I've been driving big trucks and buses for almost 35 years and believe me, you'll know when they are not balanced.
Timmy



From: cooneytunes
Sent: 9/1/2005 9:59 PM

Just a little note....Bean Bag Balancing should not cost more than 10 bucks or less per tire..wholesale price for the bags are from 6 to 8 bucks depending on how much the shop buys..and there is not any labor or time involved to put the bags inside the tires....just the cost of the bags.......if they try to charge more, ask them to hold a gun on you while you pay, because your getting robbed....

Timmy



From: denison
Sent: 9/3/2005 6:35 AM

"Coined" refers to the dimpling or dishing of the surface around each of the 8 mounting holes in the wheel. On alternate holes they are dimpled/coined in opposite directions. Four holes have the dimpling facing out, the four holes in between have the dimpling facing the other way.
When mounted as a dual pair on the rear axle, this ensures accurate mounting of the wheels relative to each other. Also there is or should be a locating pin on the hub, that fits into a smaller 9th hole in the wheel.
There are also 8 bolt wheels that have the same bolt-hole-diameter but whose mounting surface is flat. These wheels are probably hub-centered. That is to say the large hole in the center of the wheel would fit closely over an extended ring on the hub of the vehicle. I know they will fit on some M400 chassis, but my belief is those wheels do not have the same load capacity as the wheels with the coined mounting holes, and probably don’t take the same size tires either. I only KNOW they will fit on an M400 chassis because I saw a Winny having that type of wheel on one side of the rear axle, as well as having the coined type of wheel on the other side of the rear axle. I don’t know if this worked all-right, since that Winny had not been driven on the highway for years.
The wheels with the flat mounting surface should not be mixed with the ones having the coined mounting surface. A Winny chassis would take one type or the other, never both.
Incidentally, any light truck wheel whose "diameter" size has the .5 after it, -like 16.5, 17.5 or 19.5 - is a one piece wheel and was designed to use tubeless tires, although they can use tube type tires as well. (Why would anyone want to?) There are NO split rims in those "half-inch" sizes for Light Truck wheels.
The wheels on most passenger cars are lug-centered. The lug holes have conical sides, and the lug nuts have a matching taper. That centers the wheel on the hub.. That is how the 5 bolt Budd style 17 inch split rims on my Winny are centered.