Cooper St Maxx tires - rubber cracking (1 Viewer)

[Mountainpassing]

Now I've heard that armor all foam stuff is a good product. Not to make yer tires shine (tho it do) but to recondition the rubber from time to time.

I spray that gunk real thick and heavy on the sides and just let it dry. It seems to penetrate and "re-rubber" the side walls quite nice like a leather conditioner or something.
I tell myself it'll make the tires last longer cuz it really does condition them well, like putting vaseline on old dry window rubber will work.
Obviously you can't "safely" do the tread tho.

seems to help a little.
I run duratracs cuz i can't find a better slick surface tire that has some aggressiveness, tho im interested in the st maxx next perhaps..

Bf tires suck for the wet and slick winters here. maybe the 3 version is better idk.

 

[Spdstr280Z]

Couple of caveats... I have blown a tire on the street too. When I was younger and poorer, I would run tires to the belts. My friends still give me crap for the time I ran a CRX on two mini spares for a month until I could get tires. I won't take those risks any more, so I know where you are coming from. Also, you are the person responsible for the safety of your vehicle, so you have to comfortable. Having said all that, based on what I see in your pics I would just put "tires next year" on my mental checklist and go about my business. If you are otherwise really happy with the tire it seems you have an easy answer. Also, figured I might take some crap for this, but someone above beat me to it, maybe some UV protection on the next set to see if it helps ? Assuming they get cleaned occasionally. I'm currently a fan of 303, it has a great reputation, and doesn't look like you spread baby oil on everything when it dries.

Jason

 

[andyquoll]

I run duratracs cuz i can't find a better slick surface tire that has some aggressiveness, tho im interested in the st maxx next perhaps..

Bf tires suck for the wet and slick winters here. maybe the 3 version is better idk.

I’ll say it again, the Maxx is phenomenal in winter conditions! Our other car is a Subaru that gets dedicated snow tires, and it and my 80 feel equally planted. Certainly it helps that the 80 weighs twice as much. But I have never felt the need for more traction. I’m actually more comfortable with the 80 in a crazy storm with the lift and all. There’s been times when the passes have one foot of snow on them. Plus when s*** is really evil triple locked beats awd.

Anyway, the maxx really surprises me in winter since it has very little siping. Must be the rubber compound.

 

[andyquoll]

Couple of caveats... I have blown a tire on the street too. When I was younger and poorer, I would run tires to the belts. My friends still give me crap for the time I ran a CRX on two mini spares for a month until I could get tires. I won't take those risks any more, so I know where you are coming from. Also, you are the person responsible for the safety of your vehicle, so you have to comfortable. Having said all that, based on what I see in your pics I would just put "tires next year" on my mental checklist and go about my business. If you are otherwise really happy with the tire it seems you have an easy answer. Also, figured I might take some crap for this, but someone above beat me to it, maybe some UV protection on the next set to see if it helps ? Assuming they get cleaned occasionally. I'm currently a fan of 303, it has a great reputation, and doesn't look like you spread baby oil on everything when it dries.

Jason

Yeah I hear you. There’s worse than that pic on some of these tires actually.

Having a high speed blowout on tires that looked a bit worse than these is why I’ll be replacing them. I’m lucky that blowout was a rear tire! Lifted truck + big tires + instant blowout is terrifying.

Curious about UV protection... my full size spare has an early 2016 date code and it’s in perfect shape. I’ve been lazy about rotating it in though and it hasn’t seen nearly the same amount of sun.

 

[andyquoll]

If you are otherwise really happy with the tire it seems you have an easy answer.

Yeah. I think based on this thread and more research today, the Maxx is still the tire for me. Just need to get used to getting under 50k miles on them.

Nothing else hits the performance balance that I want. I like the grabber x3 as an alternative but I don’t want to spend 1300 and find out they suck in winter.

 

[White Stripe]

View attachment 2285195

That's not bad cracking, I wouldn't worry about it. I would say those tires still have some life in them. I would just monitor them. My krawlers have looked like that for a long time. What is your street pressure?

 

[andyquoll]

That's not bad cracking, I wouldn't worry about it. I would say those tires still have some life in them. I would just monitor them. My krawlers have looked like that for a long time. What is your street pressure?

I run 32 front and back. Down to 12 when I wheel but I get that back up before hitting pavement.

One of the tires is slightly worse than that in spots. That tire in the pic just had sun conveniently on it. Kind of torn what to do. I am nervous from having a tire blow up on me in the past that was dry rotting. I guess I'm answering my own questions here... If I don't feel safe I should replace...

I also noticed one of my tires has a 2015 date code and it is in significantly better shape, even though it's had the same miles and sun exposure. Maybe 2014 was a bad year or those tires were stored poorly at one point?

I do think I will replace these with the Maxx again, given that I'm looking for good winter performance from a tire that is more aggressive than an AT, and with good sidewall pro. No other tire seems to fit that. If I have to replace every 5 years that's the price I will pay.

 

[White Stripe]

I run 32 front and back. Down to 12 when I wheel but I get that back up before hitting pavement.

One of the tires is slightly worse than that in spots. That tire in the pic just had sun conveniently on it. Kind of torn what to do. I am nervous from having a tire blow up on me in the past that was dry rotting. I guess I'm answering my own questions here... If I don't feel safe I should replace...

I also noticed one of my tires has a 2015 date code and it is in significantly better shape, even though it's had the same miles and sun exposure. Maybe 2014 was a bad year or those tires were stored poorly at one point?

I do think I will replace these with the Maxx again, given that I'm looking for good winter performance from a tire that is more aggressive than an AT, and with good sidewall pro. No other tire seems to fit that. If I have to replace every 5 years that's the price I will pay.

The structure of the tire is the belts. If the cracks are deep enough where the belts are exposed or close to being exposed then it's time to replace. The belts are usually around 3/16 below the rubber. Doesn't hurt to replace earlier.

 

[andyquoll]

The structure of the tire is the belts. If the cracks are deep enough where the belts are exposed or close to being exposed then it's time to replace. The belts are usually around 3/16 below the rubber. Doesn't hurt to replace earlier.

Good to know! Thanks

 

[45Kevin]

These are my ST/Maxx mounted Sept. 2020 on my 45.
No signs of cracking and the 45 lives outdoors year round.

They have been a great tire.
However, on my AWD van I put the Falken Wildpeak/3.
The van sees a lot more highway than off-road and I figured they might be a bit quieter.
They also have performed very well in all circumstances.

 

[Nay]

A hybrid is a close to AT as I’m willing to go.

That’s impressive on the ice! How’s the highway ride/noise with that tire? Tread life?

I’ve considered the STT pro, but I don’t really need tread that aggressive. I could be convinced if it isn’t super loud and squirmy on pavement though...

I have 16K on mine and they are still 18/32 tread. I’ve had them at 90 mph and they are smooth without any sketchiness. One thing I really like about the Coopers is they ride really nice at regular PSI. I ran my 37” ko2 at 24 PSI. No issue with that, the Coopers are just a lot nicer if you are on and off pavement a lot and don’t want to mess around airing down for comfort.

Here is some other ice testing. They do an excellent job of consolidating the powder skiff over ice we often have in CO. I almost eat it walking up to show how the controlled slide performs.





A common misperception is that siping works best on cold ice, despite there being nothing to work with in terms of moisture wicking off the surface. This is why I like good winter MT’s better in CO than AT’s, and why I don’t really care about so called winter tires because unless you stud them there’s really no extra magic.

And of course offroad, they are money.

Steelbender Flat Pass

 

[Nay]

Here’s a pic at 16K. You couldn’t pay me to run ST Maxx over the STT Pro, which is a much more modern tire.

And here is the Ultraterrain at 13K. These replaced the Duracraps that came with the 4Runner when I bought it. I cannot say enough good things about this tire. I had it in 18” of blizzard snow and it just crushed everything. I have to try really hard to make it slide on hardpack. The more modern the tire the better, it’s that simple.

But I like to drive without having to care a whole lot about things like ditches...so...

 

[andyquoll]

But I like to drive without having to care a whole lot about things like ditches...so...

Haha that’s precisely why I pick the 80 over our Impreza when it’s really nasty.

Impressive lack of wear on those Coopers!

 

[Nay]

Haha that’s precisely why I pick the 80 over our Impreza when it’s really nasty.

Impressive lack of wear on those Coopers!

I think of them as the ultimate aggressive AT. I haven’t found a downside. Obviously nothing is the best in every possible condition, but just driving reasonably to the conditions (like actually braking before corners unlike my ditch vid where there was ice underneath and I figured I’d wing it) is all it takes.

They balanced without a lot of weight and I haven't had to touch them. Amazing how much the brodozer market has improved large tires, 37’s are like the 33’s of yesteryear with far better wear and traction.

My only caution is they run true to size. 3/4” taller than the ko2 they replaced. It was enough I had to do a bit of extra trimming and adjust my wheel spacers down from 1” to 3/4” (my 17” rims are stock backspacing).

 

[greentruck]

...I personally think 6 years is pretty reasonable for a tire sitting outside.

You can run more miles in fewer years, but you can't add more years to tires with fewer miles. Once rubber pops out of that mold at the factory, it has a limited lifetime. Exposure to UV, ozone, and too much sun in general saps the life out even quicker. 6 years is a good long life for a reliable tire. After that, it's like chugging milk from a carton in the back of the fridge before checking the Sell By date.

I've been living with KM skittishness in winter here in the Midwest since the first version went on one of my trucks years ago. I consider it a worthwhile tradeoff for the otherwise excellent perrfomance. Back then BFGs were the only radial MT and the other MTs equally sucked in winter - or worse. If you're that old, you've learned not to over drive your tires in winter conditions. Tire technology has come a long way in that time and each version of the KM has seen improvement. Our set of KM3s just went on, so I await learning how much these have improved over the KM2. I tend to rely on finesse rather than my tires in winter. I'm old enough now not to need to get there in a hurry so long as I'm in one piece.

 

[zonker]

I have 5 years on my S/T Maxx’s. A little bit of cracking on my end.. but nothing to worry about in my opinion. Best tire I have ever had on a four wheel drive. That includes going back to my ‘73 FJ40 with Commando’s.

Bottom line.. I am headed for another set of S/T Maxx when my current ones are chewed up!!

 

[andyquoll]

I have 5 years on my S/T Maxx’s. A little bit of cracking on my end.. but nothing to worry about in my opinion. Best tire I have ever had on a four wheel drive. That includes going back to my ‘73 FJ40 with Commando’s.

Bottom line.. I am headed for another set of S/T Maxx when my current ones are chewed up!!

What mileage have you put on yours? How much tread remaining?

I still think it's a bit weird to see cracking. My last set of KM2's went 7 years with no cracking at all and still had 50% tread left. And that was on a built 4runner that spent all its life outside in CO, in the sun.

I'm 95% sure S/T Maxx is where I'll be again. That other 5% is looking at the STT Pro.. But I'm not willing to give up highway ride, noise or winter performance so I think the Maxx is calling me again. That STT just looks so cool though, haha.

Thinking about putting some 303, or some other protectant, on the next set. Need to research that further.

 

[bwesty]

Thats not unusual to have that kind of cracking and aging of rubber, especially if stored outdoors. Its rubber, it will deteriorate in that fashion, I've had that on many sets of BFG tires over the years. The tires will be fine, run them but just monitor the cracks.

 

[zonker]

I have right about 24k on my S/T’s. I should have measured the tread depth.. but today got in the way. I am guessing that I have about 50% tread left. I am however very soft on the throttle and I use the transmission quite often as a manual for slowing. With that said my cracking is very minor and in my opinion nothing to worry about. I live at a little over 5,000’ and see my fair share of snow in the winter and off-road adventures are at my back door. There is no question I will be sticking with this tire for the foreseeable future as I believe the performance is exactly where it needs to be for my style of use. Which is 40% off-road and 60% on road.