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Tires cupping

AWDWAGON

Passed Driver's Ed
Location
Barrie
Anyone other than myself notice that the tires are cupping?

The cupping is happening on the inside edge. Tires have at most 20-25,000 kms and were rotated once since the car is a 2018 - 1.5 year old. Car is a 2018 Golf Sportwagen 4-motion

In order to minimize cupping, I was told me that i'd need to rotate tires every 8000 kms faithfully. :screwy:


Cupping
by AWDWAGON, on Flickr

***UPDATE*** 07/21/2020

Had an alignment done, here are the results:


4 wheel alignment
by AWDWAGON, on Flickr
 
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Reggie Enchilada

Autocross Newbie
Location
nowhere
Car(s)
yes
Did you notice that your tires are overinflated? Look at the wear mark in the first picture, it's the triangle at the edge of the tread. You should see wear down to the tip of that triangle when the tire is properly inflated. When underinflated, the wear pattern will be past the tip of the triangle. When overinflated, the wear pattern will be above the tip of the triangle.
 

AWDWAGON

Passed Driver's Ed
Location
Barrie
I had the tires inflated to 42 PSI (this is what's on the car's sticker) last year. Overinflated for one person 90% of the time.
I use winter tires from November until end of March. Winter tires did not cup/feather at all.
The All seasons (pictures) tires are 225/40-18 XL rated btw. I now inflate the tires to 36/37 PSI. Better ride, but the cupping seems to still be present this year.
To be honest, I think i will have to replace these tires, as they now make to much noise.
 

Reggie Enchilada

Autocross Newbie
Location
nowhere
Car(s)
yes
Did you check on the load index of the new tires and compare them to the OEM ones? If there is a difference, you'll need to adjust the inflation pressure accordingly
 

sandmangti

Autocross Newbie
Did you notice that your tires are overinflated? Look at the wear mark in the first picture, it's the triangle at the edge of the tread. You should see wear down to the tip of that triangle when the tire is properly inflated. When underinflated, the wear pattern will be past the tip of the triangle. When overinflated, the wear pattern will be above the tip of the triangle.

I do not think so.
Triangle marks location of the wear indicator bars on face of tire. Spaced around tire.
It is a little far down from shoulder to wear this far.
 

jmblur

Autocross Champion
Location
Massachusetts
Car(s)
2017 Golf R
I do not think so.
Triangle marks location of the wear indicator bars on face of tire. Spaced around tire.
It is a little far down from shoulder to wear this far.

This is correct. The triangle does NOT indicate anything about useful tread. Normal driving shouldn't be anywhere near these, although high performance driving might be.

Tire cupping is a sign that SOMETHING is imbalanced or bent. Wheel balance, bent rims, worn bearings, blown shocks, bent axle, etc. It has little to do with the tires. If you're seeing if on all 4 I'd say whoever balanced the wheels did a shit job. Go get the wheels a road force balance.

So you feel any vibration or other issues?
 

AWDWAGON

Passed Driver's Ed
Location
Barrie
No vibration at all. Cupping is worst on the two back wheels. Keep in mind that this was a fairly new car when it started cupping (summer 2019). Tires were mounted and balanced at the factory. These are the OEM wheels and tires. I just didn't rotate tires at all. I would run tires in the same place all summer, rotating tires the following season only.
 

sandmangti

Autocross Newbie
This is correct. The triangle does NOT indicate anything about useful tread. Normal driving shouldn't be anywhere near these, although high performance driving might be.

Tire cupping is a sign that SOMETHING is imbalanced or bent. Wheel balance, bent rims, worn bearings, blown shocks, bent axle, etc. It has little to do with the tires. If you're seeing if on all 4 I'd say whoever balanced the wheels did a shit job. Go get the wheels a road force balance.

So you feel any vibration or other issues?

The triangle indicates where the tire wear indicators are on tire.
Firestone uses an F on Semi tires, Michelin uses the binba guy on semi tires. In the OP'S picture you can ever see the wear bars at this location on his tires. I am adding a picture of my Bridgestone Dealers on my Ford Ranger. Enlarged the picture to show triangle.
In middle of picture as bad as it looks enlarged. Dueler not a performance tire so triangle indicates what? Class? Wear bar location.

Does not make me an expert in all, but this I know. I am a Lead Process Engineer for Bridgestone in it's largest TBR, Truck Bus Radial plants. So for 24 years, 14 as a Process Engineer in tire room, I have looked at tires every day. I see many wear indicator marks.

Racing tires might have such indicators but PSR passenger tires normally not.

Cleaned truck today.
 

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AWDWAGON

Passed Driver's Ed
Location
Barrie
Having the tires over-inflated to 42 PSI would not cause cupping?
If not, then it seems like everything is pointing towards an alignment. Will be doing it at the dealer, since it's a 4 motion, as per above recommendation.
It's definitely not bad shocks/struts as the car is still fairly new (noticed the cupping @ 20000 kms or 12000 miles give and take), I have double that now.
 

tmw2442

Autocross Newbie
Location
Approved NPC storage contanier
Car(s)
Mk7 R
Most like due to toe in setting of a stock alignment...take out 1/2 of the rear toe VW puts in stock.
 

jmblur

Autocross Champion
Location
Massachusetts
Car(s)
2017 Golf R
Having the tires over-inflated to 42 PSI would not cause cupping?
If not, then it seems like everything is pointing towards an alignment. Will be doing it at the dealer, since it's a 4 motion, as per above recommendation.
It's definitely not bad shocks/struts as the car is still fairly new (noticed the cupping @ 20000 kms or 12000 miles give and take), I have double that now.

Over inflation would cause even wear on the center of the tire. Cupping behavior is due to vibration or another non-constant behavior (bent components, worn bearings, etc.). Is there any vibration or noise at all? Definitely worth getting the wheels balanced.


Most like due to toe in setting of a stock alignment...take out 1/2 of the rear toe VW puts in stock.
Toe wear is even around entire tire, it wouldn't be spotty like cupping.
 
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victorofhavoc

Autocross Champion
Location
Kansas City
What a few others said... This is due to bad shock, vibration, or balance. Doesn't matter if the car is brand new, new cars come with bad shocks occasionally.
 

jimlloyd40

Autocross Champion
Location
Phoenix
Car(s)
2018 SE DSG
No vibration at all. Cupping is worst on the two back wheels. Keep in mind that this was a fairly new car when it started cupping (summer 2019). Tires were mounted and balanced at the factory. These are the OEM wheels and tires. I just didn't rotate tires at all. I would run tires in the same place all summer, rotating tires the following season only.

If you have ruled out shocks etc sometimes you just get a bad set of tires that do that. I had it happen on a set of Michelin PS3+ tires and Discount Tire just replaced them and the next set was fine.
 

sandmangti

Autocross Newbie
Is the wear all the way across or a good way across?
If due to suspension then I think wear would not be on edge only.

Google.
Suspension components like shock absorbers, struts, bushings and others wear out with miles travelled. The result can be a tire that is no longer able to roll smoothly down the road; instead, it bounces slightly. This bouncing creates uneven points of pressure on tires, leading to tire cupping.

https://www.bridgestonetire.com/tread-and-trend/tire-talk/tire-cupping
 

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