What was the reason for my front right tire getting cupped??

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atn_chargers
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I just got the alignment done. Unfortunately, it is only a temporary fix, as I will have to buy new tires to completely get rid of the tire noise. So I wanna know, is it the camber or toe that got my tire cupped?? And what will I need to do once I get my new tires, to avoid ever having this problem again? Just keep getting an alignment every couple of months?? That would suck!!!



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Where on the tread is the cupping occurring?

How's the tire pressure? If the tire is overinflated it can lead to cupping.

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MagikDragon
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thats usually a tire inflation issue. why was your caster changed so dramatically? everything else doesn't show signs that it would wear your tires out though.

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Poyzinous
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Camber, toe being that negative and underinflation would cause an offset oscillation in wheel rotation causing cupping. I recomment getting new tires, THEN an alignment. Totally.

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atn_chargers
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Some of you guys say over inflation, some say under inflation. Which is it? My toyo proxes t1r can hold a maximum pressure of 50 PSI. I had all four tires running 40 PSI. Was that the issue?
Modified by atn_chargers at 10:17 AM 11/18/2009

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G_whizz
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I run mine at 35psi all around.

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zozoka1212
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G_whizz wrote:I run mine at 35psi all around.



Kendahl
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Run the tire pressure recommended for the car, not the max pressure on the tire. You can find the recommended pressure on the door jamb.

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atn_chargers wrote:Some of you guys say over inflation, some say under inflation. Which is it? My toyo proxes t1r can hold a maximum pressure of 50 PSI. I had all four tires running 40 PSI. Was that the issue?

Modified by atn_chargers at 8:27 AM 11/18/2009
Depends on where the cupping is, center or shoulders. If the shoulders are fine, but the center is gone, that would be explained by your overinflation.

Recommended is 32 or 35 PSI, can't remember which. Going up to 40 is great for fuel economy, but reduces the contact patch area and also causes uneven wear. This gets worse when you're driving long distance and the pressure goes up due to tire temperature. So your 40 PSI tire which is already 5 PSI too high, is now 7-8 PSI over inflated because of the temperature change.

Those before numbers also look VERY off. Specifically the camber. I was under the impression that we only have 4 wheel adjustable toe. If that's the case, how did the alignment tech magically add .8-1 degree of negative camber to the front wheels? Same with your caster. 2.8 degrees is WAY out of spec.

Am I reading the report wrong? I'm seeing before being the initial reading and actually being the current reading after adjustments. Is that correct?

Where was this done?

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atn_chargers
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I had it done at a Nissan Dealership.

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At 50*FYour tires should be 35psi front and rear for 19" tires.I keep mine at 32 front, 31 rear. The Sedan 17" is recommended 30 front and rear, but Mine is AWD and I want an extra lb for Steering response/economy, and one extra for the added awd weight. Tire pressure should be set cold, before going out driving. The air heats up in the tire after its been driving around.

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atn_chargers wrote:Some of you guys say over inflation, some say under inflation. Which is it? My toyo proxes t1r can hold a maximum pressure of 50 PSI. I had all four tires running 40 PSI. Was that the issue?

Modified by atn_chargers at 10:17 AM 11/18/2009
I have the same tires in 20" on my car and I have 38 psi in mine. IMO, you do not have an inflation issue.

It looks like the tech tried to adjust the toe and ended up making the camber worse (looking at the camber before/after numbers). Not his fault though because the camber is not adjustable.

Is your car lowered? A new set of SPC upper control arms will give you the adjustments you need, but at a cost. I have them on my car and they have worked out great for me.

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38 seems a little high... if you have 245 front and 275 rear I think all you need is 36psi...

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The actual setting before had your front right toe completely out of range, which is why that tire cupped.

I've said this over and over. CAMBER doesn't cause tire cupping. The toe will destroy a tire in a matter of a few hundred miles if it is completely out of spec. Out of spec camber will cause the tire to wear faster on the inside or outside depending on too much negative camber or positive camber.

Now on to the tire pressure issue. During accident reconstruction school, we learned that running around 38-40 psi was optimal. I saw where someone mentioned that if you were at 40 psi cold and then the tires heated up you would be another 7-8 psi higher. That is not the case. We tested the theory and set tire pressure cold @ 32-35 psi. When tires were hot, they were 8-10 psi higher (40-45). When they tested 38-40 psi cold and the numbers only increased 4-5 psi. We also learned that running in this 38-40 range, helps with side wall flex(rolling over), increased mpg, better handling and less damage to the tires from heat. As you can see from the tests the tire is only heating up half as much as running a lower colder temperature. We all that heat is one of the destroyers of tires along with alignment specs.

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I agree with RED_DET

The Toe is pretty far out of spec BEFORE. The toe is what will kill your tires. I burned 20K miles of tread in ~50 miles with bad toe. It will trash your tires. Keep an eye on the toe.

Also with 19" rims, depending on the size of the sidewall, I would be between 37-40 PSI. Extra protection for the rims + better handling/response + with the stiffer sidewalls will wear tires evenly.

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RED_DET wrote:The actual setting before had your front right toe completely out of range, which is why that tire cupped.

I've said this over and over. CAMBER doesn't cause tire cupping. The toe will destroy a tire in a matter of a few hundred miles if it is completely out of spec. Out of spec camber will cause the tire to wear faster on the inside or outside depending on too much negative camber or positive camber.

Now on to the tire pressure issue. During accident reconstruction school, we learned that running around 38-40 psi was optimal. I saw where someone mentioned that if you were at 40 psi cold and then the tires heated up you would be another 7-8 psi higher. That is not the case. We tested the theory and set tire pressure cold @ 32-35 psi. When tires were hot, they were 8-10 psi higher (40-45). When they tested 38-40 psi cold and the numbers only increased 4-5 psi. We also learned that running in this 38-40 range, helps with side wall flex(rolling over), increased mpg, better handling and less damage to the tires from heat. As you can see from the tests the tire is only heating up half as much as running a lower colder temperature. We all that heat is one of the destroyers of tires along with alignment specs.
The 7-8 PSI was 5 PSI over spec plus the 2-3PSI due to heat for a total of 7-8 PSI.

terrycs
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Poyzinous wrote:38 seems a little high... if you have 245 front and 275 rear I think all you need is 36psi...
Low A/R tires are usually labeled for more pressure. IMO, the stickers on the door were meant for stock tires.

When I first lowered my car, I had increased front tread wear on the inside because the camber could not be adjusted back into spec. To me, that is the same thing ... increased tire wear which is why I put in new adjustable upper control arms as soon as they became available. My fronts are wearing perfectly even now.

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Sentientbydesign wrote:
The 7-8 PSI was 5 PSI over spec plus the 2-3PSI due to heat for a total of 7-8 PSI.
I'm not gonna argue with you, not worth my time.

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Poyzinous
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optimal pressure can be different with higher camber as well. If you have a little extra camber, well then an extra pound or two wont hurt. The stickers are for stock tires, by the way. Even though its 30 on my sticker, I keep 32 front and 32 rear cold because of my own research/knowledge/craps&giggles.

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i have herd the g series are notorious for eating up tires, i also read here on nico that if you lower the tire pressure it will help this issue alot try 30 to 33 psi i lowered mine and it put a stop to this problem hope it works for you good luck


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