Tire Balance - force balance?
 

I just got some mpsc mounted and balanced...

Tire shop recommend a 'FORCE balance'.. which I had never heard of before.

Seems they apply a roller to the tire which simulates a car load (850#) on the tire, then high speed rotation, and add wheel weights.

they said the can index the tire, find out of round tires, etc...

-but a little pricey... $27.50/wheel..

did I get taken?
is this worth the extra ~10 bucks vs a normal high speed balance?

whats the consensus?

TIA

I always find myself spending the big bucks on balancing, then after the first weekend, I have picked up so many track worms on my tires that they are not exactly balanced any more. THis is the last time I"m spending extra for the high tech balancing. Just my two cents.

I used to bust tires and a kid and the technology has improved. The shop I use has a computerized machine that is a spin balance and it has gage to test if its out of round when they do that it puts pressure on the tread of the tire to test this. I do not believe it puts a load on the tire. Never hear of it, maybe someone else has. I can't see how putting a load on the tire would change its balance our shape, but I could be wrong.

It is a very popular way to balance your tires.

Traditional spin balancing machines only balance the wheel/tire for weight. However, it doesn't account for the varying spring rate associated with the tire itself.

The most popular balancing machine is the Hunter Road Force balancer. By applying a load via a roller to the assembled tire/wheel assembly, the balancer can detect variations in the tire and wheel combination that might lead to vibrations when driven. These variations may not be present in spin balancing (because the weight is equally distributed), but will be present when driven.

Hunter has a good "how it works" explanation here:

http://www.gsp9700.com/pub/features/how.cfm

The Hunter system can also allow the tech to unmount and rotate the tire relative to the wheel to match up the opposing "problems" on the tire and wheel--i.e. the high spring rate portion of the tire and be placed over the low spot on the wheel.

It's a spectacular way of separating you from cash.

I know a bunch of VERY successful road racers who still use a static "bubble balance".

Or don't worry about balance at all.

The qustions are the same for this as most items in our sport. the road force balance is better, do you need it is the question. If it is a race only tire the answer is most likely not, a slick wont give a damm about balance form raod force. If it is a dual duty steet and track tire it is easily worth 10 bucks

+1 on the comment about track worms. I can't tell that the tires are still round some times it gets so bad, particularly regarding heavy braking.

That looks like the machine.

- I just taped the new weights.... and there's less over all weights then the last set.

maybe I'll never know the difference.... and warp the rotors instead! :icon107:

It is the machine and the process.

You lost me.:confused:

I've always done that for street tires, and since I get my track tires done for free typically, well, I haven't told them NOT to - but I do think its overkill.

Jeff,
I'm just saying I wonder if I'll notice the difference, cause I'll probably over heat the rotors anyway, which is way worse than out of balance tires...

now I wonder if I'd notice the difference if I didn;t balancing at all.

Anyone skip balancing race tires? at $120 to mount an balance a set, it is tempting.

[QUOTE=.... Anyone skip balancing race tires? at $120 to mount an balance a set, it is tempting.[/QUOTE]

I know a few that skip it, but only when mounting fresh Hoosiers. On some cars/means of mounting, the tires actually rotate on the wheel after the first few runs - negating the precise balance job.

I marked my tire with a chalk line at the valve - and sure enough it had moved ~6-8 inches.

I agree - for street tires it might be worth the extra $, but not for track. Tire boogers easily ruin that fine balance in no time.

I have access to Hunter 9700s at work and balance my street tires as best as the machine can render. I use a digital spin balancer at home for the track tires but only do a standard center weight spin balance when they are new. Once they are used the only way you could balance a track tire is to cut off all the boogers first. If you don't they will shave themselves off on track and the added weights will work against you. I don't bother.

As mentioned by Glen above a track tire will rotate on a wheel when used agressively and therefore the use of a roadforce balance machine is mute for track applications.
I saw some race teams in the Ferrari Challenge a couple of years ago at the Canadian GP balance the wheel without the tire then slap on the slicks. I have been doing this with good results (won all of my DE's!)
Save your $$

I do do it for my street Porsche though...