K-Spaz

Fixed by balancing? Uhh, no...

https://www.corvetteforum.com/forums...t-be-done.html

marinablu67

If the wheels were aftermarket, I was going to say that they could possibly be out of round. The tire manufacturers put a red or yellow dot on the sidewall that should be in line with the valve when installed, which aid in balancing(less weights)on new tires, but yours are 10 years old. How many miles on them? I wouldn't worry about the weights for now, and be lucky that you don't have any vibrations, but replace them soon.

c05v3tt3

I skimmed the post since there were 9 pages with a lot of back and forth. In any event, it sounds like a tire shop and/or RR crossings were the culprit in your situation to a bent wheel(s)? That's not to say mine don't exhibit some out of roundness but hopefully less likely given they are OEM and have yet to be touched by a tire shop. To be fair, I bought the car used so I don't honestly know what the first 4K miles of road conditions were like. That said, I also wouldn't be comfortable using a rubber mallet to re-shape them but on the other hand I certainly wouldn't want to replace them either. At this time, I'm comfortable with the amount of weight used and solid driving experience but appreciate the insight either way.

K-Spaz

All you need to do is hit a seam in the road and they bend. This isn't something new. I just helped another member find a similar issue on his car (also Zr1). I'm not really speculating here, they're bent. I'd bet you virtually every wheel on ANY car is bent to some degree, unless it's never been driven It's easy enough to check with your phone and a jack. Spin the wheel and watch the video. Pretty simple. You don't need a machine shop to diagnose it. As to "My car doesn't shake", well, that's because you haven't driven mine. Keep in mnd if you follow that thread and another of mine, you'll see that according to the Tire Rack, a tire that's out of round by more than 1/10th of an inch is completely within manufacturing tolerance and is a-ok A wheel such as yours with 1/2 a POUND of weight, is within spec. Go read their site and FAQs on balancing. So, there are varying degrees of acceptability. My degree is shall we say, slight.

marinablu67

A 1/2 pound is 8 OZ. The front passenger side wheel has 12 weights @ 1/4 OZ=3 OZ! Looks worse than it is!

c05v3tt3

Right, they have 4.5K miles on them. I drove the car home 250 miles with no vibration issues and routinely held 70-75 mph on the highway with a few spirited runs to 100+ mph. The driving characteristics seemed solid to me aside from the typical road noise and the natural tendency to follow any pavement groves which seems normal for such wide tires. I have plans to change them out here after this summer.

c05v3tt3

Fuzzy math I suspect but another poster did the math correct above so I'm good.

marinablu67

Unless I'm idiot, 12 weights X.25oz = 3oz

Look at your picture, do the weights not say .25 on them? If I'm wrong, please correct me.

c05v3tt3

You're correct, the fuzzy math was a comment towards another poster. No worries either way.

marinablu67

It's partly my fault for putting "A 1/2 pound is 8 OZ" out of context! If one of my wheel/tires took 8 0z of weights, I would want to know what was wrong before I drove the car.

HOXXOH

The specs for Goodyear passenger car tires in the '60's, limited the max out of balance to 6 oz. Above that, those tires got recycled. Above 4 oz and up to 6, they got shipped abroad. Those less than 1 oz went to Detroit for new cars and all the rest went to North American dealers. I don't know what other manufacturers specs were (I assume similar), but that's why most new cars never had wheel weights.

The automated tire mounting machine at the Vega plant, could pick up a wheel from a supply line on one side and a tire from the other side, mount it with 32 psi air and transfer it to the auto assembly line every 7 seconds.

K-Spaz

Which is why I think I just learned a new lesson with tires last month. Never buy from a mfgr that sells tires to the factory. The Michelin tires I got are complete ****. Not nearly as bad as the Continentals I warrantied out (That a RF balance machine could not even balance) , but still not good. I used to buy take-offs from TR back in the 90s for my F bodies and I went years without having a weight on 2 of 4 wheels. I would buy 2 or 3 sets at a time so I had them when they had take offs available. They came from cars that went to SLP industries to become firehawks, and the Eagle GSCs they took off were sold for about 1/2 price. Those balanced perfectly, every time.

Since that time I put so few miles on cars I never took note that all the crap tires are sold retail. I REALLY got an education with this last purchase for my C6 where the tires are so bad, the mfgrs should be ashamed of themselves.