Tire Cupping on the ZR1

[Dynomite]

Does anyone have experience with "Tire Cupping" on the ZR1?

What are the symptoms?
What are the causes?
What are the solutions (Before or After)?

[Starman]

You didn?t say where the cupping is, front or back.
The symptom is the cupping,
Usually the cause is something loose. If the back, could be someone tightened up the suspension in ?droop?.

Solution is to find what is loose, worn tie rod end, ball joint, shock or bushing on the front. On the back, loosen the suspension struts and retorque when wheels are carrying the vehicle weight. Also check shock, bushings etc for slop.


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[DRM500RUBYZR-1]

Pictures please?
Need to see the wear first?
Thanks,

Marty

[Dynomite]

Originally Posted by DRM500RUBYZR-1

Pictures please?
Need to see the wear first?
Thanks,

Marty

Front tires......had a small vibration at 60-70 mph.

The wheel weights were installed on the new tires (a year aago) toward the center of the car inside of the rim on one tire and toward the outside of the car (inside the rim) on the other tire which I thought was a bit strange. The guy balancing the tires today thought there was some "cupping" which I have never heard of and could not really see on my tires compared to images on google.

Any way......after the wheel balance both wheels had wheel weights on the inside and toward the outside of the rim (a couple small weights each place on both tires). The tires were balanced by the same guys who installed the original wheel weights on the tires when new.

Took it for a "spin" at speeds up to 90 mph as a test and balance was perfect with zero vibration at any speed......so I am now thinking I have no problem with relatively new tires with just a few thousand miles on them

I just never heard of "Tire Cupping" before and was interested if anyone else had heard of the term

[zyal8r]

Not on my ZR-1 or even a Corvette at all, but... I had what was described as cupping on my truck last year. Cupping as defined is an uneven wear, or sometimes also called scalloping, of the tread. In my case, I could see it in the tread - one lug was higher than the next one behind it, and that seemed to continue around the two front tires, on the inside of the tires. I tow a camper with it. My theory is, although I have a WDH on the truck, the front tires run lighter in the inside from the weight of the trailer on the back, plus constant up/down movement probably contributed to it. I knew I was delinquent in rotating them. Turning corners with these tires on the front produced an odd noise and felt loose. Rotated the tires to the rear - the noise followed the tires and the steering returned to normal. The now-rear tires eventually returned to normal wear and 10,000 miles later, they are completely fine. They have not been rebalanced.

Glad you got yours squared away with rebalancing!

Mike

[DRM500RUBYZR-1]

This is tire cupping.



Marty

[DRM500RUBYZR-1]

Most common causes are out of balance or failing shocks, but there are others.

A very distinctive wear pattern.


Marty

Sharing pictures might help

[Dynomite]

Originally Posted by DRM500RUBYZR-1

Most common causes are out of balance or failing shocks, but there are others.

A very distinctive wear pattern.



Marty

The "cupping" on my corvette tires is really not that visible in the photos below on the inside or outside of the tread of each tire.

One other cause which I shall check is Toe Alignment which is obvious how that might cause tire wear.......
Toe was excessive and reset to less than 1/8"👍

It is just difficult to imagine "cupping" or more wear every 4 or 5 inches around on the tire circumference



I expect that if one front tire is cupped it is tire balance.....
If both front tires are cupped it be Toe Alignment.....
Or other issues may cause one or the other tire to be cupped.....

In the photos above I do not see the cupping on either tire..... (I am not going to remove the tires to get photos of the inside tread which is essentially identical to the photos above)

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