kking1997

I just had my new tires mounted on a set of new C6 Z06 Factory Repos with sensors this morning and the tire shop called and said tey were having to use what seemed to be alot of weight (5 oz) to get them to balance.

Has anyone else experienced this problem? Is this to much weight to get them to balance?

They did say the wheels were running true.

MagicMtnDan

Here's the answer to your problems - find a shop near you that has a Hunter GSP9700 (you can do it here)

kking1997

The tire shop has the Hunter gsp9700 machine. So now what?

johnodrake

Are they using it? Ask what the Road Force Number is. Lower is good. I averaged a 4 on my BMW with 8 being the highest.

And Yeah, I think that 5oz is a lot.

H&J

When I use to mount tires, back in the '70's, and got a balance issue like you discribe I would break the bead and rotate the tire 180 degrees. The theory being a heavy spot in the rim is too close to a heavy spot in the rubber. Worth a try to save weight.

TheKomoman

5 is about the limit they will use. My repro Z06 wheels required quite a bit of weight, around 4 on the rears, the fronts only needed around 2. So it's not at all unusual. If I had shelled out $3000 for a custom set of wheels I would scream bloody murder, but you do get what you pay for and $800-1200 wheel sets really are "cheap" so I'll just sigh and move on. While having to use that much weight isn't a good thing the consensus seems to be that it's really only a problem at sustained high speed (130+) and a much bigger problem on fronts than rears.

tv_dir

I just had all 4 tires replaced. I used a place that had the Hunter Road Force Balancing. They had to turn the tires 180 a couple of times, but I have very few weights. The car rides better then new.

Make sure you get the RFB. That WILL help your problem. Unless your rims are out of round.

Good Luck!

OregonC6

This sounds like a good idea. I know it works with the abrasive grinding wheels I use for lapidary work-exactly the same principle is described by most manufacturers. These wheels turn much faster than a cars and the imbalance is more sensitive to position. Keep adjusting the tire and my bet is that eventually you could almost balance it without any weights that's the way the high speed abrasive wheels behave anyway.

kking1997

I was kinda wondering if that might be the case with the repo wheels. I am sure not all repo's are that way but would venture to guess that most would require more weight.

If I had spent $3000 or more on a custom set I would do exactly the same.

As long as they run down the highway smooth then I don't care. I don't see sustaining speeds of over 130+ for long periods of time so I guess they will be okay. I will find out tomorrow how well they drive once I mount them on tonight.

Thanks everyone for your responses.

TheKomoman

That was exactly how I made my decision to keep them. I have about 800 miles on the wheels and no trouble, no vibrations. Good luck!

2HD's2vettes

I also have the zo6 replicas. The most weight I have are 12 - 1/4 oz. or 3 oz. total - to the left front. all wheels have weights on them, 1/4 oz. form 3 to 12 or from 3/4 to 3 ozs. They do ride near perfect, at high speeds also.

0vetteshop

This is called "indexing" and the HUNTER machine has the capability to instruct the tech exactly what position to relocate the tire on the rim to achieve the lowest road force

cthusker

I have CCW wheels and they required almost no weights at all..... They run better then the factory wheels......

AU N EGL

Did you say REPOS ?? The C5 repos where notorious for not ballancing well.

DentonVette

If you have to put a lot of weight on a wheel, I think that the problem is usually either a bad wheel, or incorrect wheel centering on the balancing machine. I learned this the hard way, as I have a Toyota Truck which is notoriously hard to balance because of the large center hole. The wheels are supposed to align with the balancing machine using the hub bore, but in reality they need to be aligned using the center hub and in many cases also the lug nuts, not just the center hole. Although this problem is much amplified on larger truck wheels, such as 17" or above used on most SUV's today, the issue is concentric wheel mounting problems and all wheels may have mounting issues. Wheels must have accurate center mounting and distortion free clamping so that the center of the shaft of the wheel is properly located on the balance shaft.
I tried Discount Tire on several occasions before I realized that they are dishonest about their technology and use only generic wheel centering cones. After spending $500.00 on new truck tires, I spent hours on multiple occasions waiting for re-balancing and hearing excuses like the prior machine must have been out of calibration, the tires are bad, etc. I did some research on the net and found out about these balancing issues. Confronting Discount with my knowledge that Toyota truck wheels need special adapters, they finally offered a "Road Force Balance", which they usually charge extra for. Of course, during the process, they initially used just regular cones (probably worn out) to mount the tire, then finally with the "road force machine", some half *** generic mounting plate adapter and the wrong lug nuts, (which could not be tightened up correctly, and then only three instead of six). Of course, after more research, I finally got fed up and called their customer service line, and Discount's national service rep called me back and admitted that they won't buy the better and proper devices because of cost. The simple fact was that no one at Discount at the store level, even knew that this was an issue, and they did not know about the more vehicle specific cones and flange adapters available. Even with the high tech Hunter machine that "road force tests", the system is useless unless you use the proper and not worn out centering cone or if possible the right cones with the better flange plate adapters. Believe it or not, my local Toyota dealer had the right cones and flange adapter specified by Toyota, and my problems were solved, for an extra $50.00. During this process, I also discovered why my multiple purchase Acura Legend rear tires kept cupping out right away; because they were not being balanced properly by Discount, and were bouncing. You can't check wheel/tire perfection unless the wheel is perfectly mated to the machine. Some brands such as Toyota, Lexus, Mercedes, and others demand that their dealers use specific custom cones or flange adapters to balance certian wheels in dealer shops. I am sure they are replacing far fewer "defective tires or wheels" because they can get a good balance with custom centering devices.

I have wondered what problems I will encounter when I go to get new tires, or have a flat with my C6 wheels and tires and need re-balancing and mounting. The wheels and tires you get from the factory are balanced using wheel specific cones or adapter flanges that perfectly align the wheel and prevent misalignment of the wheel in relation to perfect true center on both planes. In other words, the wheel is balanced the same as if bolted to the car. Hunter has specific equipment for different wheels that match. Other brands also make better cones and adapters. Most car and tire dealers use the the same basic cheapo cones to balance all of the wheels. The cones may be miss-sized, worn out, or the machines can be out of calibration. If in doubt about the centering devices used on your wheels, have the balancing tech balance the wheel and tire, and then move it 180 degrees and spin to check the balance. More likely that not, it will show it out of balance if the correct match centering device is not used. BTW, "Road Force Machines" only real claim to fame is that they can test for sidewall variance, which could result in a rough or seemingly unbalanced ride; the procedure in and of itself does not ensure correct balancing. The dealer must still use the correct and not worn out mounting accessories. If the wheel is not centered right, all of the machines "conclusions" and recommendations about tire position and "indexing" is just misleading.


Hunter has specific equipment listed at this site:

The link is to Hunter Precisions Centering Devices.

http://www.hunter.com/pub/product/ba...3T/3203T-7.htm

No, I don't work for or know anybody at Hunter Engineering Company.

If anyone on this great forum has any experience with or knows of specific cone adapters, etc., that we Corvette owners should request, for use in conjunction with wheel balancing, please post.

timd38

Same here.