Nuances of tire balancing

mike f · 07-26-2004, 03:55 PM

Well, I was hoping to get my tires to last until the fall and buy a new set in the spring, but as luck(or lack thereof) would have it I got a flat tire. A screw punctured it very close to the sidewall, rendering it unrepairable. So with mouse in hand and tirerack on the web, a new set of SO3's will be on the way

. I was just wondering if there is any difference between balancing methods. I have brought my tires to a local guy in the past and things seemed okay. The guy uses a standard type machine. My wrench can also mount and balance and is a serious racer(so maybe uses different equipment) but I don't know the cost difference. Are there different balancing methods and do they make a real difference on a car that will not really see much track use? I always take the wheels off myself and bring them to the shop, so that would not affect my decision.

Zeke · 04:09 PM

Balancing today is greatly aided by the computer balancer. If the tire mounter will look for any heavy spots on the tire and place them opposite any heavy spots on the rim (like a metal valve stem), that's a good begining.

Nest step is to distribute the needed weights on either side of the vertical centerline of the tire/wheel weight mass. This is where the computer is the best. If the tires then pass the 100 mph test, all work is finished.

If not, then some more work is in order. The tires should be checked for round on the computer balancer. They also have to be checked for round on the car. Assured that they are, a strobe type of balancer is used to find any other balance problems such as rotors out-of-balance. Also, it is necessary to spin the tire to a higher speed than the computer balancer preset and fairly low speed. When the tire grows due to speed, it can "grow" in a irregular way. This can be compensated with the strobe on-the-car final balance.

You must then keep the tires on the same corners and on the same referrenced studs.

Superman · 07-26-2004, 04:20 PM

A minimum of 9/10ths of those nose-pickers barely know how to run the balancing machine. Very few of them actually understand what they are doing. But the tire usually (not always) comes out balanced. Worth a try. I'd look for a tire shop that can mount the tire without scratching the wheel. Some tire mounting machines are "touchless."

mike f · 07-26-2004, 08:09 PM

I agree with you, Super. The guys at this shop are minimum wage types. Although the machines are not touchless, to date no harm has come to my wheels. My only problem seems to have been a slightly out of round tire which my wrench picked up last go around when the car was in for alignment and corner balancing. Otherwise the local shop has been okay. I guess I really need to get some cost info and take it from there. If a big difference, it may be worth going with the local guys first and to my guy only if any problems. Once I find out, I'll post some numbers just to give other folks an idea what it would cost them if interested.

david914 · 07-27-2004, 06:32 AM

Boy, I need to find a good shop around here. I spent the better part of a weekend cleaning and polishing my rims only to have the lips scuffed up by the tire monkees. Nothing that some Mother's and elbow grease won't fix, but still...

You'll probably have more luck with the SO3's than I had with the Dunlops I just put on mine. Three weeks of chasing a BAD shimmy problem! Finally ended up replacing BOTH front tires due to them both being out of round. Of course, it took three complete balancings at two different shops, several hours of playing musical wheels-n-tires, and a couple hundred dollars in mounting/balancing and alignment fees to figure it out. It was aggravating! Of course, now I cringe at every little road wiggle from the steering wheel.

mike f · 07-27-2004, 10:10 AM

Just what do you do if a tire IS out of round? Does the manufacturer generally excahange them? Since I ordered from tire rack, shipping them back and forth can become an expensive proposition.

masraum · 07-27-2004, 10:43 AM

It's my understanding that the best balance is a road force balance. And that in addition to greater tire life the car will also ride and handle better. Not many shops have the machine to do that so you may need to look around a bit.

grant lyon · grant lyon's Garage

If the tech doesn't know how to put all the balance weights on the inside (inboard) side of the wheel, the're not as fastidious as they might be.

BGCarrera32 · 07-27-2004, 12:02 PM

My guy does a "split dynamic" if necessary, where all of the weights are on the inside of the wheel, but some are near the outside edge and some are inboard near the back side of the paddles (on the Fuchs). This keeps the weights/tape/etc off the outside polished face you see on the car, but gets the wheel acceptably balanced across the width of the tire/wheel itself. We the use foil tape to secure the weights on after they have been stuck on with VHB tape (double sided tape).

If it were me I'd take them to the guy that is the avid racer...

david914 · 07-27-2004, 12:03 PM

Quote:

Originally posted by mike f
Just what do you do if a tire IS out of round? Does the manufacturer generally excahange them? Since I ordered from tire rack, shipping them back and forth can become an expensive proposition.

I found out the hard way, one at a time. Tire rack was quick to send me out a replacement each time at no charge. They issued a pickup order for the bad tire and all I had to do was bring the tire back into work where UPS picked it up. They also offered to reimburse me for the remounting and balancing (up to $20 each). Very easy and very accomodating of them. Good thing as I was already frustrated with the whole situation.

david914 · 07-27-2004, 12:11 PM

Quote:

Originally posted by BGCarrera32
My guy does a "split dynamic" if necessary, where all of the weights are on the inside of the wheel, but some are near the outside edge and some are inboard near the back side of the paddles (on the Fuchs). This keeps the weights/tape/etc off the outside polished face you see on the car, but gets the wheel acceptably balanced across the width of the tire/wheel itself. We the use foil tape to secure the weights on after they have been stuck on with VHB tape (double sided tape).

If it were me I'd take them to the guy that is the avid racer...

Yeah, I'd really like to have all mine redone that way. When I first had them mounted and balanced, I asked that they only put the weights on the inside. When I noticed the shimmy problem, I played it safe and had them do inside and outside. I need to find a really good tire balance guy around here. Anybody know of one in the Richmond, VA area?

Wil Ferch · 07-28-2004, 05:48 AM

BGCarrera ofers good advice.
You can get good balance by placing all weights on the inside that way.
Aluminum heating duct tape if good too to hold these in place.

Sometimes, the tire /rim mounting is such that you need a lot of weights to balance. Often, simply remounting the wheel to the tire by 90 degree offset from original brings you back in closer balance and ends up using less weights.

Wil

mike f · 07-28-2004, 11:04 AM

Just a quick follow up.
Approximate prices for mounting and balancing:
my wrench ~$180
Goodyear ~$120
local tire shop $65

Of course my wrench will do a much more thorough job, but enough to justify the extra cost?? Don't know what the difference(if any) between Goodyear and the local shop would be as far as technique. Has anyone else had this done? Are these prices ballpark range?

david914 · 07-28-2004, 11:36 AM

One of those is outta the ballpark

Actually, I don't quite know why the huge difference. Had mine mounted and balanced at Tire America (Sears) for $71. Of course, I had problems with the two fronts (yes, BOTH) being out of round and it took a couple of weeks two figure out what was wrong. Had I taken it to an (ahem) expert, it would've cost me more money, but probably less aggravation.

braddb_82SC · 07-28-2004, 01:12 PM

I've had nothing but problems using chain tire shops (like Wheel Works) for balance. On one install I returned twice for a rebalance. They never got it right. A trip to my porsche mechanic solved the problem.
On two subsequent installations I have purchased tires at Tirerack and asked my mechanic to install. The latest install was yesterday and it cost me $120 for mount/balance. It's worth it, there is not a shimmy to be felt.
My experience would suggest Fuchs require special handling.

-Brad