balancing problems--weights on inside and out?

I got some new shocks installed on my xj today at Sears. I also had my BFG AT Ko's (30x9.50 w/ 50k miles on them). The ride improved greatly, but when I hit 50 on the highway the tires vibrated badly.

I assume they did a crappy job balancing them and will return tomorrow for another try, but my question is:

I noticed the lead weights were on the inside and outside of the wheels. I've never seen this before. They are usually only on the outside of the rim. Is this ok?

Jeff C. said:

I got some new shocks installed on my xj today at Sears. I also had my BFG AT Ko's (30x9.50 w/ 50k miles on them). The ride improved greatly, but when I hit 50 on the highway the tires vibrated badly.

I assume they did a crappy job balancing them and will return tomorrow for another try, but my question is:

I noticed the lead weights were on the inside and outside of the wheels. I've never seen this before. They are usually only on the outside of the rim. Is this ok?

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thats normal but the vibes are not

Balance weights are usually more or less evenly distributed on the inside and outside of the wheel rim. That's assuming the heavy spot on the tire is symetrical to the axis of the tire, though. If the tire is heavier toward the "outside" then obviously it will need more weight on the "inside" to balance it.

Your tires were dynamically balanced. That's good. Static balancing is only using weights on one side.

bottleworks said:

Your tires were dynamically balanced. That's good. Static balancing is only using weights on one side.

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Well, if one wants to nitpick, a good static balancing job will put the weights uniformly on both sides - i.e. if you find that it is off statically by 2 ounces, you put one ounce on each side at the light spot, which ensures that at least you don't make the dynamic balance any worse. At least that's how I learned to do it, and I've found that often a very careful static balancing is better than a crappy dynamic job done by careless people who don't even scrape the mud off the rims, etc.

Matthew is correct. "Static" balancing means the tire is balanced while at rest (static, not rotating) as opposed to dynamic balacing, which is done by spinning the tire on a machine. Static balancing is done with bubble balancers, which have no way to determine or indicate if the heavy spot is on-axis, or offset toward the inside or outside of the tire.

Static balacing works well for smaller tires and for narrow tires where the heavy spot can't get very far off the plane of rotation. Our monster off-road tires, though, are big, heavy, and wide. They are much more difficult to balance. Static balancing often can't do the job. In fact, from the number of posts I see about balance problems, even dynamic balancing often doesn't do the job on the big tires.