Cooper stt pro’s with cupping

BBDOC

New member
I have been getting cupping on my 315 STT pro’s. I have about 15,000 on them. On road they are getting louder and bumpy now. At first they were amazing. They are still great off road and stick to everything. I have had them rotated 3 times ~5k, checked balance and alignment as well. I have the Dynatrac lift with fox shocks. Still love my rig but a little let down on the life span of my coopers. I always run around 32-33 psi. I have had my whole suspension looked at and retorqued on 3 different occasions and always told that everything looks great. Any one else having issues with there STT Pro’s? Any thing I can do to help with lifespan?


Sent from my iPhone using JL Wrangler Jeep Forum mobile app
 

JTCO

Meme King
Post a picture of the cupping if you can. I'm on my 2nd set of Coopers. I got them used with about 15k-20k on them, no issues so far. My first set was fine as well. I also know a few other people with them with no issues. Hard to say what you've got going on.
 

ddays v2

Member
That's odd. I've got over 40,000 miles on the 37's on my JK with no cupping and half of the tread left. Cupping can be caused by quite a few reasons as mentioned but sounds like you keep after them. Is it all of them or just one or a couple? A bad shock(s) can cause tire issues.
Also, they will get louder as they wear. Mine were really quiet new but have gotten progressively louder. They are M/T tires after all
 

BBDOC

New member
I’m ok with it getting a little louder to be honest. I just had a custom pipe done to get rid of my trash can in back and it’s a little louder as well. I just thought it was weird to have this issue so early. The guys at the dealership and 2 off road shops can’t figure it out. It is mostly one tire that was the worst. Had that one up front left when I really noticed it. Had them rotate and put the fronts in the back and doing some burnouts are flattening them out a bit now. Had stock shocks and springs with 315’s and was told the tire may be a bit heavy. I put on the Dynatrac lift which I love and another simple alignment (no control arms or track bar changes yet). Hopefully no further issues. They think it may be just a bad tire since it’s mostly the one tire. I will try to get some pictures. Thanks all[emoji106]


Sent from my iPhone using JL Wrangler Jeep Forum mobile app
 

JTCO

Meme King
It is mostly one tire that was the worst. Had that one up front left when I really noticed it. Had them rotate and put the fronts in the back and doing some burnouts are flattening them out a bit now.

Check your toe angle just to be safe. It's easily done with a measuring tape. If it's way out, it can cause wear although it doesn't usually look like 'cupping.'
 

Cruzzze13

New member
Cooper SST's, 37x12.50R20's cupping on rear after 7K miles, new Terraflex kit and Falcon adjustable, can't rotate to the front or it will get real bad, Discount Tire told me it's not from shocks but no rotation, had them rotated at Jeep at 4K......next?
 

JTCO

Meme King
Cooper SST's, 37x12.50R20's cupping on rear after 7K miles, new Terraflex kit and Falcon adjustable, can't rotate to the front or it will get real bad, Discount Tire told me it's not from shocks but no rotation, had them rotated at Jeep at 4K......next?
I've owned 3 sets of these tires (not 37s though). Each set, I have rotated every 3k and have never had any cupping issues. If you rotated yours at 4k, that shouldn't be an issue at all. You shouldn't be having any cupping. What's your air pressure at?
 

Cruzzze13

New member
This was on the back only, front is perfectly fine. Have rotated corner to corner also. Seems like it was literally overnight when I started hearing them and then checked them.
 

Top