Cooper ST MAXX

Advice on the right rolling stock for your 4WD
Wombat200
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Re: Cooper ST MAXX

Unread post by Wombat200 » September 3rd, 2013, 5:27 pm

Just a brief review, but different to most people's use...

I've had them on for about 7000km now, and while they havn't seen a heap of off-road use, I have done lots of snow driving on them. Soft slushy snow, hard-packed snow, fresh soft dry snow, both over bitumen & on good dirt roads. As well, lots of steep / winding roads on wet & at times icy bitumen. I can't fault them in this area, they have had fantastic grip in these situations.

The small amount of use on soft mud has been encouraging, too, in situations that would have seen my old AT22 crap-treks hopelessly bogged, these things have pulled through well.

They seem to be wearing evenly, too.

So far, a tentative thumbs up....

greenmamba59
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Re: Cooper ST MAXX

Unread post by greenmamba59 » January 22nd, 2014, 5:45 pm

I have had the st maxx's on a np pajero for 20000km and have found them extremely noisy and they are all showing extreme uneven wear across the tyres. The treads are scalloped and the lugs are wearing about 50% more on the front of each lug compared to the back if the lug. I had new shocks fitted at the same time that the tyres were fitted and have rotated and balanced. They will be lucky to make another 20k. They are good off and on road in terms of performance but noise and longevity are problematic.
By the way I did 85000km on the factory road tyres with no issues.

Peter Aawen
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Re: Cooper ST MAXX

Unread post by Peter Aawen » January 22nd, 2014, 9:27 pm

What size are your tyres greenmamba, and what pressures are you running in them? Is your vehicle your daily driver, & if it is, how much of your travelling/total km driven is on the dirt/off road? Is it likely to be as much as 50% of your kms travelled (which is a fairly high amount for a recreational 4WD that is also used as a daily driver) or somewhat less?? What sort of rotating/balancing regime have you had them on since the original fitting, or are they still where they were fitted when you bought them??
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RogerAnything
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Re: Cooper ST MAXX

Unread post by RogerAnything » January 26th, 2014, 10:06 am

I put a set of STmaxxs on my Bravo in May 2012. I put 39 000kms on them up to December last year. They were great tyres on and off road, quiet, great steering response, good traction in mud and rocky climbs when dropped to 18-16 psi. I was very happy with them. However, late November last year I was cleaning the truck and noticed that two of the tyres had split the rubber around the bead. One tyre had a split about 14 inches long and the other had three splits about 4 inches long. My local dealer said they were seeing this happen with a few STmaxxs, usually in the smaller sized 225/75/16 and 245/75/16. My tyres were 225/75/16 on a Bravo table top which is running unladen about 95% of the time. Pressure was 32lb in front and 30lb in rear. Cooper replaced them at half price ($150 ea). So up until that point I was exremely happy with the STmaxxs. I now have a new set on as I bought two more to match up and will see how the new set go. I hope it was just an early production run glitch and they have it sorted now. The dealer advised to not run below 34lb on the road and thought I might of had them too low. But there is very little weight in my Bravo and the stiff sidewalls of the STmaxxs seemed to handle 32 and 30lb well. I'll keep them on 34lb and monitor progress with the new set.
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Peter Aawen
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Re: Cooper ST MAXX

Unread post by Peter Aawen » January 26th, 2014, 11:46 am

Hey Roger, what tyre pressures/sizes does your tyre placard specify??

It might pay to get your vehicle weighed (at the load it normally runs at) and then see if your tyre bloke has the guide from the Aust Tyre Industry Handbook that tells you what pressure to run in those tyres under that load. If they don't have the handbook guide, you can often get pretty close to that by reading the Max Load/Max Pressure info on the side wall of the tyre & working out how much of that load each tyre is carrying, then work out what percentage of the Max Load the actually carried weight is - then work out the same percentage of the Max Pressure, add 4psi cos you are going to be moving not just standing, and use that pressure as a start point for running your tyres.

The 'smaller volume' tyres like those you are running often need to be run at higher pressures than the bigger tyres, and of course the contact patch on the tyres will be significantly smaller than with a larger tyre so it will need to carry a greater load per squ inch, but still, that sort of split is usually associated with either running the wrong pressures (significantly wrong!!) or with hitting things on the road/track or even kerbs.... and if you don't purposefully drive up the kerb at speed &/or under load, you really shouldn't be getting that sort of damage with tyre pressures that are anywhere near good for your tyres.
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

RogerAnything
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Re: Cooper ST MAXX

Unread post by RogerAnything » January 26th, 2014, 12:54 pm

Peter,
Original size tyre was 205R/16. The manual states pressures unladen 26psi front and rear. Pressures laden, front 28psi and rear 63psi. My Bravo weighed 1750kg as weighed at the local garbage depot on exit when empty. Since then I have added an Avenger Winch (about 30kg) and a Long Ranger Tank. So add maybe another 100kg for a total about 2 tonne. I am running slightly bigger tyres (225/75/16) as there is a much better selection in this size than the original 205/16s. As my Bravo spends at least 95% of the time running around unladen I thought 32 (F) and 30psi (R) would be fine. Especially in the wet. It is very light in the rear and can be quite slippery on wet tar with tyres that have hardened up after a year or so. That's why I ran the lower pressures in the rear. Also it used to bounce around a lot on rough country roads if the rear tyres were inflated too high. I've just had the suspension replaced (Tough Dog 40mm lift) which has firmed things up a bit so 34psi in the rear feels quite good now.

The dealer said the split around the bead was purely cosmetic and didn't alter the structural integrity of the tyre. He said Cooper add an extra layer of rubber on the outside of their tyres and it was this outside layer that had split. He stuck a flathead screwdriver into the split to show that the inside layers were still structurally sound. Anyhow, I was quite happy to go another set of Stmaxxs as up until the splitting they have been the best 4WD tyre I have ever run. So I'm hoping Cooper have fixed the issue with the new set I'm running. I have seen other quality products fail from time to time such as Zeiss and Leupold rifle scopes (though very few Leupold scopes) and high end Shimano reels so all companies can have a problem with a certain product from time to time. So I'm quite happy to give the Coopers another go. Cooper were excellent to deal with as I emailed them via their website and received a reply early the next working day.
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Peter Aawen
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Re: Cooper ST MAXX

Unread post by Peter Aawen » January 26th, 2014, 1:30 pm

A tyre that holds a larger volume of air than the OE tyres, like those you've fitted, should probably need LESS air pressure inside them to carry the same load, and finding the rear end to be slippery on wet tar with new or old tyres tends to suggest that your tyres may well be running a bit high in the pressure stakes already, as does the bouncy stuff on the rougher roads.... So maybe it would be a good thing to check with the tyre industry handbook, or work out what percentage of each tyres max load is being carried on them and then reduce the Max pressure to the same amount, add that 4psi cos you are driving & not just sitting there, and use the resulting pressure as your cold start pressures - you could even just try running 26psi all round and seeing how close it is to doing the right thing using the 4psi 'rule of thumb', adjusting up or down accordingly.

It could also pay to check the tread depth right across the tyre tread of the original tyres you have remaining, and see if that depth is less in the middle than on the edges, especially on the rear tyres - the fronts tend to wear off the shoulders of the tread a little as you turn & drive etc; but shallower tread depth in the middle does suggest that you might be running your tyres a bit high in the pressure stakes. Altho the difference between 32-34 or so and 26psi might not appear to be a heap of difference - it could well be enough to knock 20-30,000 km off the overall km potential of your tyres and make a significant difference in their ride & handling, traction, etc!! You may have become used to the firmer ride & handling that can come with running tyre pressures that are higher than the optimum for your load/tyres/driving style, so running your pressures a bit lower for a while might feel odd at first, but if you take the time to get used to it and you spend a week or two using the 4psi rule to check that the pressures you are running is pretty close to the optimum for your tyres, you should probably get better ride & handling overall as well as not doing quite so much damage to the tyres if you do hit anything like road debris or potholes etc.

Some people (including the odd Cooper Dealer) suggest that because Coopers ARE reasonably pressure sensitive & running the wrong pressures by too much can make them do things you really don't want them to do in a very short space of time/number of kms, it might be better to aim for a 6psi increase after an hours driving instead of just the 4psi as per the 'rule of thumb', but that is generally aimed at those who do more 'off road' &/or marginal dirt road stuff than bitumen driving. Altho if you drive in the cold and wet a lot then the lower pressures the 6psi rule will give you might well mean better traction & overall wear on those cold & wet roads. Still, I guess I'm saying that I feel that 34 psi still sounds a little high for an unladen Bravo with tyres that size on it, but only checking by using something like the 4psi rule will reveal that - and the tyre placard pressures or the Aust Tyre Industry Handbook recommended pressures are pretty good pressures to start off that process with, then fine tune with the 4psi (or 6psi) rule as you drive it and your tyre temps/pressures react to what is actually going on rather than anyone guesstimating what's right or not! I'm pretty sure the Cooper ST Maxx are a good tyre (they certainly have been for us!) but I also know that no matter what they are, anyone's tyres will work better for them if they put the effort in to give them the best chance of doing that, with regular wheel alignments, balancing, and rotations as well as using the 4psi rule or something similar as part of giving them the best chance to look after you and wear well! ;)
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

RogerAnything
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Re: Cooper ST MAXX

Unread post by RogerAnything » January 27th, 2014, 4:11 pm

Thanks for the indepth replies Peter. It's very much appreciated. I think 34psi in the rear of my light bravo is too high when it's unladen but I was just trying to do what the Tyre shop advised me. I will probably reduce it back a bit soon.

With regards to the 4 psi rule, I'm a bit puzzled. First, I must explain that I know how it works, or at least I think I do. But a year ago I was out Kanangra crossing the Kowmung Rv and dropped my tyres to 20psi. On getting back to the tar I reinflated the front tyres but as it was really hot I just left the rear tyres on 20psi and drove back to Bathurst which was at least an hour or slightly more. On getting back to Bathurst I pulled into a servo to reinflate the back tyres and hey presto the rear tyres are on 24psi, an increase of exactly 4psi which is what I should be on. So does that mean my rear tyres should be on 20psi to start off with? I figure that's a bit low, even with the tray completely empty. This year after putting the new tyres on I checked they were on 34psi and then drove to Orange and back. I probably stopped in Orange for 5 mins in a shop and then drove home again. On getting home I checked the rear tyres again and guess what? They were on 38psi, again an increase of exactly 4psi. So with either 20psi or 34 psi in the rear, I got a 4psi increase after an hours running in summer. So not really sure what to put the starting pressure on as the 4psi rule works at both 20 and 34psi. or am I missing something?
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Peter Aawen
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Re: Cooper ST MAXX

Unread post by Peter Aawen » January 27th, 2014, 4:40 pm

That 4psi increase may well vary depending on the surface you are driving on, the ambient temp of the day, how hard you are driving, how heavily you are loaded, simply because it REACTS or 'is a result of' the driving you've just done - so you can use it to confirm to yourself that the cold start pressure you chose to begin with today or on this leg of your trip was fairly right, and you can adjust your pressures as you go to reflect the changes you can see from what you've just done, & maybe even apply a bit of a judgement call on what you should use now depending on how similar the stuff you are about to do is going to be to that stuff you just finished.

Re the Bathurst trip you reported - on that day, with that ambient temp, that load, that driving style, and all the other variables, then YES, it sounds like 20 psi was pretty much right - but it might not be right today, or even right for me driving your car over the same road on the same day with the same ambient temps!! Similarly with your Orange trip, on that day, with that load, that driving style, that ambient temp, it sounds that 34 psi was about the right pressure to start with, cos your tyres were responding to the ACTUAL conditions and all the other variables on the specific days and if you started with cold start pressures and got a 4psi increase, then that was pretty much right. That's why you need to spend a few weeks religiously checking your tyre pressures and adjusting them as the rule suggests as well as making a judgement call on what pressures you should be starting off the day with, OR on what pressures you should expect to see hot right now if you had just spent an hour driving on the stuff you are about to do!! That way you will learn fairly quickly to be able to make an 'educated guess' at what the right pressure will be for the driving facing you in the next hour or so, and then you can use the 4psi rule to confirm that guess was right, or give you an indicator that it wasn't quite as right as you thought - but every variation in the day, load, surface, speed, traffic conditions etc can need a change, it's the experience that you are accumulating, learning & developing enough in order to get it close enough to right most of the time! Most people we've travelled with/trained this way generally only take 3 or 4 weeks to get the 'what pressure should I start with today/now' part of the deal down pat, altho some manage to do that in less than 2 weeks and some might even take 8 weeks or more (altho I haven't found too many like that yet, apart from a couple of fella's who were either almost brain dead or purposefully stuffing it up, cos even their non-driving wives were doing a better job than they were at making a pretty accurate 'educated guess' on what pressure to put in their tyres now, given the surface they were about to drive on, the days' temperature, the load they had on, and the speeds they were likely to be driving!)

Anyhow, give it a go, TRY IT, play with it, and actively monitor your tyre pressures as any of those variables change. Modify the pressures you are running when you are about to change surfaces, adjusting up or down depending on what you expect to drive on in the next hour, keeping in mind that once your tyres are hot you will need to work with pressures reflecting what they SHOULD be after driving an hour or so on that surface if you were starting from cold, then adjusting up or down as if you'd done that accoring to the 4psi rule, and check them again an hour or so later so you can confirm &/or fine tune your judgement. It's an ongoing learning process, and it needs to be fairly intensive for the first few weeks, but like I said, I don't know too many people who haven't been able to become pretty damn good at making the initial judgement call fairly right within a few weeks of practice, AND you get a chance to adjust it and fine tune it as you go! And once you are comfortable with the pressures you are estimating to start with being fairly close to what they should be, you can either keep on checking & confirming every hour after a change, & keep doing that for as long as you feel the need to keep confirming your skill; or you can rely on your judgement & just go with whatever changes you make, just so long as you always use a reliable air pressure gauge to set your pressures to start with - and have it on had to check later if you need/want to!

The 4psi rule doesn't tell you what is right for what you are about to do, ie the stuff/surface you are about to drive on, with whatever load you have on, in whatever ambient temps there are, and using whatever driving style you might choose to use; but the experience you gain durning that intensive first few weeks should let you get close, and after an hour or so of driving the 4psi rule allows you to confirm that the starting pressure your judgement led you to choose was reasonable (if not correct) for all those variables and you also get the opportunity to adjust your pressures accordingly if necessary, in a tried & tested manner that you can do time & time again, each time providing far more reliability & accuracy than just guessing; or, if you are now about to pull off the bitumen and head into the sticks & ruff stuff, you can make an estimate about what you are about to face/drive on & adjust your tyre pressures to what YOU JUDGE them to need to end up being once they've done after an hours driving on the sort of stuff facing you now - and an hour or so later, you get to check and confirm that your estimate was reasonably correct or not & adjust accordingly! Like I said, most people don't take a heap of time doing this to get pretty good at making those judgement calls/estimates, & the constantly reliable method of confirming doesn't change; but hey, if you got it wrong this time, the experience you have means it was probably pretty close & the reliable application of the 4psi rule to the results lets you fix that and fine tune your pressures as you go. Make sense??

PS, every day/trip is going to be different, but you will develop the judgement & experience over time that will let you get close to right and then fine tune as you go, but don't forget that it doesn't necessarily mean you need to be changing your tyre pressures all the bloody time!! Tyre pressures are just ONE of those variables that you have control over!! If you think that 20 psi is too low for what you are about to do, but only a little, you could maybe chose to do the next bit a little slower, it's amazing how much difference dropping just 10kph off your avg speed can make on your tyre pressures! Similarly, if 34 psi is too with the load you have on now if you are going to poke along at 60 kph, you could drop your pressures a bit, or possibly you could comfortably drive at 80 kph or even 100kph instead of at 60 kph?! You get to choose!

YOU have the key to all this, the 4psi rule is just a tool that allows YOU to reliably & consistently check your judgement calls using this tool and refine them (& your tyre pressures or any of the other variables you have control over if you wish) as you go along! Nothing really hard about it, just so long as you've got a reliable air pressure gauge! ;)
An Ex-Service person is someone who thought enough about their country & how great it is, how lucky we are to live here, to write a blank cheque made out to 'The People and Commonwealth of Australia' for the value of 'Up to & including my Life!'

Shaker4x4
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Re: Cooper ST MAXX

Unread post by Shaker4x4 » January 27th, 2014, 5:21 pm

This looks one of the best 'aggressive' A/T tread patters I've seen, being an excellent touring tyre if you don't plan sticking to highways. I'd almost consider them myself, but Cooper's Mileage Warranty only covers the confines of the City or town they are purchased in. As soon as you roll them on roads different to the City's Roads, out goes the Mileage Warranty (by rights.) I think it's a warranty term they only adhere to in certain scenarios. The STT does not have a Mileage Warranty at all, because it's classified as an off-road tyre and subject to use beyond the scope of what they are confident warranting. The rubber compound on their more aggressive tyres is prone to chipping and if abused, will break/tear a lug clean off and upon inspection, it's easy to see the harder rubber compound at work where the lug was. One guy complained of an ST blowing out it's side wall and frankly, I believe the sidewall cord design coupled with the rubber compound is not ideal for airing down/bagging the tyres. I guess you have to be a Cooper fan and had a good run on them to say they are good and recommend them. I've never personally run a Cooper and not game to. Some people are well aware of them and steer well clear.

Aside from my opinion, they look worthy if you're a Cooper lover. The side lugs are to assist in climbing out of wash-outs or wheel ruts. Most new generation tyres have this feature in one form or another I've noticed.

gqjay
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Re: Cooper ST MAXX

Unread post by gqjay » January 28th, 2014, 6:16 pm

Quoted today $365 a corner, :eek: haven't had the need to buy offroad tyres for awhile..

Also to try and keep this thread on topic. There is a locked thread about the 4psi rule with all the information...

rat patrol
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Re: Cooper ST MAXX

Unread post by rat patrol » January 31st, 2014, 7:20 am

Shaker4x4

Mate I am on my 8th set of S/T's in 12 years on 4 different 4bys About 6 years ago i got a set from fourby's where i have got every set from since. At about 70,000 ks they still had 6mm average tread left and had been rotated every 10,000ks (with evidence to back that up) At that point they started to throw tread blocks, i took them in to show the blokes there, and they all know that i tour and work in remote areas on many many dirt roads,
Well the upshot was they gave me a 50% pro-rata warranty on those tyres so I got a new set supplied fitted balanced and a wheel alignment for half the cost of a new set of tyres. After doing 70,000 ks on them I was more than happy with that .:D
Cheers
RAt

gqjay
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Re: Cooper ST MAXX

Unread post by gqjay » August 1st, 2014, 1:49 pm

1st 8 thousands in the st maxx on the px ranger and waiting now for a rotation and wheel alignment to be done. Most of the k's have been on road running at 42psi and have been as low as 18 on the beach and dirt/Rocky terrain. The Coppers have not worn down or have uneven tread. . So, so far I'm really happy with the tyres compared to the other 4 brands I have used over the years.

mydmax
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Re: Cooper ST MAXX

Unread post by mydmax » August 1st, 2014, 6:28 pm

gqjay
If there is normal wear and it is even on the tyres, then be careful about having someone give it a wheel alignment.
Often the way it is may be perfect for what the vehicle needs but a wheel aligner will change it to the specs he thinks it needs.
Then you begin to wear tyres abnormally.
Last edited by mydmax on August 1st, 2014, 7:30 pm, edited 1 time in total.

gqjay
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Re: Cooper ST MAXX

Unread post by gqjay » August 1st, 2014, 7:21 pm

mydmax

Thanks mydmax, they didn't end up doing a alignment as it was not needed from when they did a few months ago.

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