It was with great interest that I read your tyre test (February 2018 issue), but after the second read was disappointed at the results. I was involved with Dunlop motorcycle racing tyres (D211); and if the pressures were not set correctly, the tyre would not perform at all. The race pressures required were set well below the normal and could make up 5 seconds on a race.

For example, why set a tyre at 1.4 bar to operate in thick sand, when its design optimum is, in fact, 0.8 bar? For this reason, I believe the test is not a true reflection of all the tyres involved.

We have been using Cooper AT3s on most of our vehicles with great success and they have given us better all-round performance (cost per km, off-road traction and tar road noise) than tyres supplied as OE.

[Ben Visagie]

Ben Visagie on 19th April 2018 at 3:42 pm

Yes agree, I think a 4×4 tire test is difficult, the results doesn’t convince me to buy a Grabber next time. A Cooper maybe…..

[Steve]

Steve on 20th May 2018 at 5:03 am

Cooper themselves also recommend percentage decreases from standard pressures. However depending on veh weight, ply and tyre design, one could go lower. I have not seen a 4×4 tyre manufacturer state a specific pressure only ranges as vehicles would differ in weight and tyre sizes and therefore tyre performance. If I utilised a fully kitted Cruiser, personally I would opt for the ST MaxX but tyres arent my issue and I can buy 2 full sets and a few tanks of diesel on Grabbers vs a set ST Maxxs. Normal NON LT Cooper AT3s are about the same as most other good 2 plies.

OE tyre models are most times totally different to aftermarket replacements of the same model.

Im running old Grabber ATs and just done 5000 km round trip to the Kalahari, 100s of kms of corrugations, no issues. Grabbers have softer sidewall that brought comfort but I do find bulge excessively on low pressures. Pain in the ass when rock crawling but Im aware of what I have. Without much offroad knowledge, my sister and b.o have taken their 4×4 thru Bots all the way to the Skeleton coast and back on budget Dunlop 2 ply Grandtreks. No tyre issues.

I Say drive according to what you have, you’ll be fine. If Budget is no issue, get a 3 ply… And a fully kitted Land Cruiser… Drive Cape to Cairo

Remember, tyres are like politics and sports….

On the other hand D211s .. They were designed, carcass construction etc, to be able to run at much lower pressures  than other tyres. We run 1.6 bar on the warmers as a base pressure. But then bikes and tyre sizes are almost standardised 😉

[Ben Visagie]

Ben Visagie on 20th May 2018 at 8:16 am

• Thanks, an off road tyre is suppose to be de flatable, but to what level before its becoming a risk to lose a tire? And then how many manufacturers will come to the party and helps? I have personal experience of Dunlop many years ago replacing two Dunlop Grandtreks after a buble on one sidewall. I was impressed with this. Also Goodyear stood in if you pick up a problem. My Cooper Discoverer Maxx on an Arctic Hilux cracked around the sidewall close to the rim, and the answer from Cooper is its due to overload or deflating after they have inspected the tyre. So it is not recommended to deflate the Coopers. And yes I have deflated it to 1.0 bar in the desert in Namibia. But so have I done with BF Goodrich and Goodyear with no problems. I think we have to accept that we may pick up a problem with a tyre but I expect follow up service and at least an acceptable reason and advice when buying a tyre. Cooper should tell us that if we deflate for eg below 1 bar we stand at high risk to damage the tyre? That said I am very impress with the Coopers quietness and off road grip, including sand driving though the hard sidewalls are affecting efficient sand driving, and thats probably why the sidewalls doesnt last when deflated.

[Mark]

Mark on 5th June 2018 at 5:31 pm

Ben – “answer from Cooper is its due to overload or deflating after they have inspected the tyre” – I have had the exact same experience although in my case I only dropped to about 1.6 bar on gravel and pumped up for tar – the only one to do so in my convoy. The ST Max gives me no confidence in that I don’t even know what I did wrong or how to prevent it happening to the next set. The other brands I’ve owned had zero issues running down to 60% of my recommended pressures these…75% if you lucky.

As for Steve – “I Say drive according to what you have, you’ll be fine. If Budget is no issue, get a 3 ply… And a fully kitted Land Cruiser… Drive Cape to Cairo” Oh the irony…of what I drive and have. The ST Maxxes  seem to prefer running 2.4 bar plus and the agent can’t give me recommended pressure. No, stick with your Grabbers vs R25k… More Money <> Better. I’m replacing 5 low mileage Coopers with tried and tested tyres instead. My wife jokes that the C should be a P.

[Mark]

Mark on 5th June 2018 at 5:40 pm

Ben – ” though the hard sidewalls are affecting efficient sand driving, and thats probably why the sidewalls doesnt last when deflated” – That’s what I was told by rep. Hard walls don’t like low pressures. Then I asked why my tyres that the Coopers replaced…which had harder sidewalls never had issues in Moz @ 0.6 bar or in Moremi @1.2…So simply put it’s my experience that the ST Maxxes are unique in their requirements. I’ll stick to European and Jap tyres.

[Steve]

Steve on 10th June 2018 at 5:57 pm

@Mark

yeah, when I need to I’ll change up to the Grabber AT3, cost next to nothing and Im never very heavy so logically makes sense as well. I like the look of the X3 but doesn’t match my needs and Muds/80% offroads dont give me wet tar confidence