Road Force Balancing

biggary · #1 (**permalink**) 11-20-2005, 12:41 PM

I'm hoping there is someone with first hand knowledge about road force balancing that can answer a quick question. I took my truck in to have the tires road force balanced and the first tire store (owner) said he had been in the tire business for 20 years and had never heard of road force balancing. I left immediately and went to another place that said they had the proper equipment, but when I got there they told me they cannot road force balance tires that have more than fifty (50) miles on them. He said that especially applies to 4X4's and it is due to tire cupping. Is that true or is he just trying to sell me a new set of tires? My tires have about 25-30K miles on them (mostly freeway driving) but have been rotated regularly and have minimal cupping on the edges, and about half the tread left. Should I be looking for a third tire store?

mustang67408 · #2 (**permalink**) 11-20-2005, 12:51 PM

I work for a TOYOTA DEALER (SHHHH dont tell anyone). I roadforce TIRES every day. Passenger car/TRUCK/4x4, you name it we do it. ALL tires can be roadforced. They are all either giving you a line or just dont want to do it for you. Every tire we balance , we check the RF, NEW or OLD doesnt matter. P series or LT series doesnt matter. The Hunter machine we use has settings for both.
RF'ing will cure many road vibrations, but it is not an absolute. I had tires RF@3lbs and vibrate so bad you'd think your teeth were going to fall out.
I have also had them R/F@20lbs and ride smooth as glass.
It is a great Idea to have it checked, it's no extra work for the tech doing it, the machine does all the work.
Find a REAL shop (dealer or other) who is trained with the HUNTER equippment and you should have a good exp with roadforcing.
Maybe DJ will add to this, he is the GURU here @TS in Balancing /alignments and other stuff.

biggary · #3 (**permalink**) 11-20-2005, 03:37 PM

Mustang67408 -

Thanks for the reply and information. I suspected there had to be a way of using the road force balancer even on used tires.

Just one more quick question, if you don't mind. Is this process done with the tire and wheel mounted on the vehicle or do you take it off to balance it?

Thanks again!

Picasso · #4 (**permalink**) 11-20-2005, 04:13 PM

Quote:

Originally Posted by biggary

I took my truck in to have the tires road force balanced and the first tire store (owner) said he had been in the tire business for 20 years and had never heard of road force balancing. I left immediately and went to another place that said they had the proper equipment, but when I got there they told me they cannot road force balance tires that have more than fifty (50) miles on them. He said that especially applies to 4X4's and it is due to tire cupping. Should I be looking for a third tire store?

I just can't resist here. In order for the guy at the first place not to be outright lying, he must have been in a coma for the past 30 years and just came out of it yesterday. The second guy is simply incompetent. You now know who not to ever go to again. Wow!

Here's the link to Hunter's Road Force Balancer page. http://www.hunter.com/pub/product/balancer/index.htm

Quote:

Originally Posted by biggary

Mustang67408 -

Thanks for the reply and information. I suspected there had to be a way of using the road force balancer even on used tires.

Just one more quick question, if you don't mind. Is this process done with the tire and wheel mounted on the vehicle or do you take it off to balance it?

Thanks again!

Short answer to your question is that the tire must be removed to have it balanced.

Sorry Mustang for butting in.

Paul

DJ · #5 (**permalink**) 11-20-2005, 09:35 PM

All good comments so far.

You have to remove the wheel and tire from the vehicle to have it road force balanced. What the machine does is spin the wheel/tire slowly while pressing a roller against the tread with about 1400 pounds of force. It measures the "loaded runout" of the wheel/tire combination. Then it measures, using other rollers, the runout of the wheel where the bead seats. Then it instructs the user to mark the tire and the wheel, remove them from the machine, break the beads loose, rotate the tires on the wheel to match the marks, then re-inflate and re-mount the wheel/tire on the machine. Then it spins it again to measure the results, then spins it up so balance weights can be applied in the usual manner.

OK, now what's it REALLY doing?

It models the wheel bead mounting surface as a circle that is not necessarily concentric with the rotational axis of the wheel. For the technically literate, that's the first order radial harmonic. It models the tire as a circle that's not necessarily concentric with its beads. It then computes how to mount the tire on the wheel so that the "high spot" of the tire is at the "low spot" of the wheel. Again for the technically literate, it puts the first order harmonic of the tire out of phase with the first order harmonic of the wheel such that they cancel as much as possible.

What that does is minimize the net loaded radial runout of the wheel/tire combination. In layman's terms, it makes the tread surface, under load, as round as possible, relative to the axis of rotation of the wheel.

Does it work? Absolutely. Very expensive machines are used to do the same thing with the tires and wheels that are mounted on new vehicles at the factory. The Hunter GSP9700 does it just as well and it does it in a tire shop. Ask Michelin -- their engineers bought the first six of them Hunter produced.

You can road force balance wheels at any time. I've done it with my own tires at 50,000+ miles. Tires sometimes change their loaded runout with wear, and road force balancing can improve their performance.

tripleb · #6 (**permalink**) 11-20-2005, 09:53 PM

Hey DJ,

Outstanding explanation !!!!!

biggary · #7 (**permalink**) 11-20-2005, 09:53 PM

Thanks DJ! That sheds a whole new perspective on what to expect when I find a competent tire store or a Toyota dealer with the right equipment. I know it has been said before but I want to say it again.....we are truly blessed here at Tundra Solutions to have the education and expertise that many members bring to the table (I know you have helped countless people with your knowledge and background) so I want to thank you personally for your assistance. And that goes for Picasso and Mustang67408 as well as all of the other members who have been helpful beyond expectations in answering technical questions or, in just sharing their personal experiences. Thanks for your input and knowledge and your willingness to share.

My03Tundra · #8 (**permalink**) 11-20-2005, 10:51 PM

Is road force balancing the same as spin balancing a tire? Every other oil change I have the tires rotated and spun balance. Is this the same thing?

mustang67408 · #9 (**permalink**) 11-21-2005, 12:42 AM

I told you DJ was the MAN!!

Aint this place GRAND!

River19 · #10 (**permalink**) 11-21-2005, 05:08 AM

DJ, you're the man. Nice lucid explanation.

Steve

just4play · #11 (**permalink**) 11-21-2005, 05:26 AM

I'm guessing you have Bridestones since your having a bad balancing experience.

Quote:

Originally Posted by biggary

I'm hoping there is someone with first hand knowledge about road force balancing that can answer a quick question. I took my truck in to have the tires road force balanced and the first tire store (owner) said he had been in the tire business for 20 years and had never heard of road force balancing. I left immediately and went to another place that said they had the proper equipment, but when I got there they told me they cannot road force balance tires that have more than fifty (50) miles on them. He said that especially applies to 4X4's and it is due to tire cupping. Is that true or is he just trying to sell me a new set of tires? My tires have about 25-30K miles on them (mostly freeway driving) but have been rotated regularly and have minimal cupping on the edges, and about half the tread left. Should I be looking for a third tire store?

Picasso · #12 (**permalink**) 11-21-2005, 09:10 AM

Quote:

Originally Posted by My03Tundra

Is road force balancing the same as spin balancing a tire? Every other oil change I have the tires rotated and spun balance. Is this the same thing?

No. Road Force balancing can measure and correct forces created by your wheel and tire far beyond what simple spin balancing can do. Spin balancing does not do any of what DJ posted in post #5 of this thread.

Hope that helps.

Paul

kwilson · #13 (**permalink**) 11-21-2005, 11:32 AM

DJ,

Your's was the must comprehensive response I have read ever, on any subject, on any message board. Thanks, I am now the wiser when I have to have my tires balanced.

Kevin

Eddie · #14 (**permalink**) 11-21-2005, 12:46 PM

By the way,Hunter's website has a locator feature
http://www.gsp9700.com/

Make sure you specify a road force balance,one can do normal dynamic balancing on a GSP9700.

thombiz · #15 (**permalink**) 11-21-2005, 07:54 PM

I've posted it elsewhere on TS, but it is worth posting again. When you have your tires balanced they must use a lug centric adapter to mount the tire/wheel assembly to the balancing machine. Tundra and Tacoma wheels are lug centric not hub centric. The cone mounting method commonly used for hub centric wheels will probably not work on lug centric wheels unless the manufactured center hole actually is perfectly in the center of the wheel.

If you do not use the lug centric adapter your tires will almost always be just a little out of balance.