Cooper ST Maxx Tires Uneven Wear (1 Viewer)

[motormayhem]

Has anyone else experienced uneven / cupping tire wear with the cooper ST Maxx tires? I have a set of pizza cutters (255/85) that has ~32k on them and have generally been pretty happy with them. However, over the last year or two they have been cupping more and more. Interestingly its on all 4 tires so it doesn't see related to a bad shock in one corner. The shocks and suspension bushings were new when I did the lift and tires as well. This is the first set of tires I've run with the lift, but I don't remember seeing any wear issues with the street tires the PO / I ran the first 6 months I had it. The shocks are icon and the springs are slinky.

I have a shimmy in the steering at 50-60 that is very annoying. Feels like something up front is loose / driving over a bunch of river rock. After checking rod ends and bushings a few times over I'm pretty sure its the tires. Here are some pics below of the cupping.

Besides suspension what else could be causing this? Has anyone else had issues with this tire? Its a bit annoying to trash them when most of the tread has ~20k life left on it, but I'm not sure there is much recovery from this uneven of wear. From the pics below you can see at worst there is ~5.25mm of tread depth difference between the leading edge of adjacent lugs.

 

[Irish Reiver]

I had a set of those a few years back and they did the same thing. My suspension and bushing were also all new. I never got to the bottom of it. The noise & vibration at lower speed was like driving over heavy corrugations and drove me mad. I ended up getting rid of them.

 

[elripster]

Is it the same on all 4 wheels?

In that one picture it looks like you might want to run a slightly higher pressure. Typically balance, worn parts, or a bent rim would cause that cupping / scalloping, however, low pressure can cause the tread to squirm under load and also cause wear on the outside.

If you are sure all suspension parts are good, tires are balanced, and the pattern is similar on all 4 wheels, I'd lean towards something in the tire manufacturing process that is causing this.

Frank

 

[Road Apple]

I’m running them now without cupping, but it’s not a daily driver. Just around town some and multi-day road trips.

 

[flintknapper]

I am on my 3rd set and have not had that happen with any of them. Very even wear across the tread.

What is your tire pressure? Center tread does not look like normal wear/load to me.

 

[motormayhem]

Around town I usually run 35psi. On the trail anywhere from ~14-20psi.

 

[flintknapper]

Around town I usually run 35psi. On the trail anywhere from ~14-20psi.

Should be fine then. I run 40-45 psi in mine but I am heavily loaded most of the time.

Possible you got a bad set, but I've never seen that with mine (3 sets).

 

[leonard_nemoy]

Classic cooper

 

[lumbee1]

I had the Cooper STT Pro and never rotated them. 13K miles and they were toast. Visually it was hard to see the cupping, however at slow speeds the vibration and noise was awful. I replaced them with Cooper ST Maxx and love them. I cross rotate tires with each oil change at 5000 miles and they seem to wear even and flat.

I once spotted a jeep in a parking lots with tires cupped so badly the tread blocks looked liked fish scales.

 

[flintknapper]

I had the Cooper STT Pro and never rotated them. 13K miles and they were toast. Visually it was hard to see the cupping, however at slow speeds the vibration and noise was awful. I replaced them with Cooper ST Maxx and love them. I cross rotate tires with each oil change at 5000 miles and they seem to wear even and flat.

I once spotted a jeep in a parking lots with tires cupped so badly the tread blocks looked liked fish scales.

Person I deal with at my local tire store (for the last 30 yrs.) said he doesn't recommend the STT 'PRO' tire for on pavement daily use. In fact, he learned that the hard way on his own truck.

BUT....he hardily endorsed the ST Maxx and I am currently on my 3rd set. I could make my tires last much longer than I do....but when they wear to less than 1/2 their tread depth I replace them. I need a tire that will shed water on the road well (which they do) and also handle the ranch roads on my property (which they also do).

Tire rotation is important, though I never 'cross rotate' just go front to rear.

 

[lumbee1]

Person I deal with at my local tire store (for the last 30 yrs.) said he doesn't recommend the STT 'PRO' tire for on pavement daily use. In fact, he learned that the hard way on his own truck.

BUT....he hardily endorsed the ST Maxx and I am currently on my 3rd set. I could make my tires last much longer than I do....but when they wear to less than 1/2 their tread depth I replace them. I need a tire that will shed water on the road well (which they do) and also handle the ranch roads on my property (which they also do).

Tire rotation is important, though I never 'cross rotate' just go front to rear.

I had a tiny vib in mine and tried cross rotating. The vib mellowed out and went away. BTW, I really like the softer AT carcass over the tougher MT carcass. It just seems to ride nicer. Interesting enough, the ST Maxx design is 12 years old.

I did try front to back rotating my STT Pro's after they were cupped. It actually made the ride much worse. I think they were just too far gone at that point.

 

[Rifleman]

Around town I usually run 35psi. On the trail anywhere from ~14-20psi.

I've seen tires wear like this before, turned out my customer was running to low of tire pressure (35psi) on the street just like you. We upped his tire pressure to 50 to 55 psi and that took care of his problem.

 

[motormayhem]

I had the Cooper STT Pro and never rotated them. 13K miles and they were toast. Visually it was hard to see the cupping, however at slow speeds the vibration and noise was awful. I replaced them with Cooper ST Maxx and love them. I cross rotate tires with each oil change at 5000 miles and they seem to wear even and flat.

I once spotted a jeep in a parking lots with tires cupped so badly the tread blocks looked liked fish scales.

Ya this is more towards the fish scale side of things. I will admit I don't believe I rotated these until around 30k. Maybe once before that.

I had a tiny vib in mine and tried cross rotating. The vib mellowed out and went away. BTW, I really like the softer AT carcass over the tougher MT carcass. It just seems to ride nicer. Interesting enough, the ST Maxx design is 12 years old.

I did try front to back rotating my STT Pro's after they were cupped. It actually made the ride much worse. I think they were just too far gone at that point.

Ya I rotated these about 2k ago and I suspect it has made the ride/vibes worse. They are pretty far gone.

I've seen tires wear like this before, turned out my customer was running to low of tire pressure (35psi) on the street just like you. We upped his tire pressure to 50 to 55 psi and that took care of his problem.

I may try going up in pressure a bit more and see how that goes. I might also push the toe in a little. I was close to 0 when checked a year or two back.

 

[White Stripe]

What kind of shocks do you have? Have you unbolted the shocks and felt the compression and rebound?

 

[motormayhem]

What kind of shocks do you have? Have you unbolted the shocks and felt the compression and rebound?

They are icon 2.0s. Ya they were fine when they went on with the tires and I had them rebuilt earlier this year and when I pulled them they felt fine.

 

[secretasiansam]

I had the same problem. I rotated every 5k miles. I probably ran too little pressure(35 psi). And was also bad about not airing back up after trail runs if the ride home was short. I didn't get 40k out of them. They did take a lot of abuse offroad.

 

[ozarkmud]

What is your rim width, and what width are the tires rated for? How often have you rotated? Are any wheel bearings loose?

I've had those tires briefly on other rigs and liked them. Somewhat in between a AT and MT tire, but very, very durable.

I've heard of other uneven wear complaints about these before. I'm still fond of them, but for me they're not as relevant as they were given where I live now.

Edit: Isn't the stock wheel 8" wide?

https://www.tirerack.com/tires/tires.jsp?tireMake=Cooper&tireModel=Discoverer+S%2FT+Maxx&sidewall=Blackwall&partnum=585QR6DSTM&tab=Sizes

I see 7" as ideal rim width and 8" as max.

It is an E rated tire, with pressure for max load at 80 PSI. I wonder if 40-45PSI would have served you better.

285/75R16 is the same height and matches the 8" rim width perfectly.

 

[White Stripe]

They are icon 2.0s. Ya they were fine when they went on with the tires and I had them rebuilt earlier this year and when I pulled them they felt fine.

The only time I've seen that wear personally is because of shocks allowing the tire to bounce.

 

[Tedward]

I had the Maxx tires, the cupping and the slow speed driving over corrugated steel with high speed shaking.
I asked a question about that on Mud and someone replied with one word: Shocks.
Realized the shocks had maybe 50,000 miles. Was keeping the tire pressure about 32.
I have new shocks, new tires (maxx agian) and will now up the tire pressure.
I do like the tires in the snow and what not. It was the cupping that sucked

 

[PeterTheBeater]

I would suspect the shocks but you said the shocks are fairly new, so I would guess tge lift geometry is messed up. The shocks/springs might also be improperly set up/rated for the weight that you have.

Also have STT PRO's for a year & half and they have even wear, the rig is my DD as well. Always had great results with Coopers and sold many sets to my customers. Great band for the buck.
My previous set of tires from PO was gonski but when I pulled the shocks last year there was 0 rebound in my OME's.