Vibrations

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Vibrations

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Vibrations - 6/12/2006 11:41:08 PM

Hanr3

Wheels & Tire Moderator
Posts: 3476
Joined: 5/11/2005
Status: offline

This seems to be a common question/problem.

I have a vibration, what could it be????

The most common cause of vibrations is tire imbalance. But I just had them balanced and I still have a vibration. It must be something else! MAYBE????

Did you get the tires Road Force Balanced????
What is Road Force Balance?
Your tire rotates around a center, numerous things can throw it off center, out of balance. Warped rim, broken belt, incorrect balance, lug centric rims on a hub centric vehicle, miss matched tire and rim, etc. etc. etc....

What the heck does all the mean???

Bear with me here.
When you get your tires balanced they are balancing the tire and rim as one unit. That unit may be in balance, however you might still get a vibration. Every rim and tire has low spots and high spots. In other words they are not perfectly round, kind of egg shaped. If the low spots on the rim are lined up with the low spots on the tire, you have a tire that could be balanced, yet still rotate up and down, roll like an egg. This up and down motion will cause a vibration even though the tire is balanced. How much and at what speed depends on how much out of sinc the tire and rims are. Is there a way to fix this? Yes!!!!

Its called Road Force Balance. Road Force balance will test how much lateral force (egg shape) your tire and rim assemble is pushing out, it will also test to see if your rim is round, and it will test to see if your rim is warped. The machine will give two numbers, one is the amount of force generated by the rim, and the other is the amount of force generated by the tire. The closer these two numbers are to each other, the closer your tire/rim assemble will be to balanced. You can actually have a tire that wont pass road force on one rim, yet on another rim it will. Truck tires are OK under roughly 48 pounds of road force. Passenger cars 26 pounds and under, compact cars is less. Road Force will also "match balance" the tire and rim. That simple means change the egg shape to a more round shape, or make the tire and rim more like a circle instead of the egg. Road Force balancing cost about $15 in my neck of the woods per tire, unless your tires was installed by the shop where you bought the tires and you bring them back complaining of vibrations. Regular balancing is roughly $7 per tire in my neck of the woods, Road Force is twice as much in cost. But worth every penny. As you can imagine the road force machine is not cheap, 3 to 4 times the cost of a regular balance machine. Only tires with vibrations problems get road forced, or tires that are difficult to balance (the balance floats). By balance floats I mean the machine tells you to place X amount of weight here, you do so and then spin the tire again to check balance, it comes up looking for more weight somewhere else. That is floating, once you place on the weight the machine recommends, it should come up balanced or damn close, within 1/4 ounce. Sometimes you have to move the weight a little to get a perfect balance. But a good tire tech can tell when the balance is floating. Not all tire centers have the Road Force machine. I highly recommend you buy your tires from a place that does have one. If not, you could be finding that store and paying the big bucks to find out if your tires will pass road force. I used to work part time in a service center, and we routinely would get customers from a mega-discount chain, who shall remain nameless, complaining that they had vibrations after they bought new tires from the mega-chain. The mega-chain said the tires were balanced. Yes they were, however the tires were defective, or needed to be matched balanced. That is something a regualr tire balancer will not tell you, only the road force machine. The money they saved by going to the discount chain just cost them more had they gone to a real tire store in the first place. Guess where they bought thier tires from in the future? Follow this link for mor

< Message edited by m00nwater -- 8/23/2006 2:04:33 PM >

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