How old is old for new tyres

Athol
Thats my belief as well as they would be worn out before being to old.

Murray

;;;;;
Athol
Thats my belief as well as they would be worn out before being to old.

Murray

;;;;; Not unlike us Muzz ...

I would be prepared to wager that chipped tyre was on the REAR Cuppa? :)
Cheers,
Peter
OKA196 motorhome

And you'd be correct Peter, rear passenger side.

Cuppa
That a perfect example of how old tyres harden up chip in the rough stuff. l have expirenced this myself years ago with some 2nd hand ones l bought, never again since then.

Murray

This same scenario unfolded for me, cooper stt, spare brand new but 3 years old on a swing out tyre carrier, so i bought 3 new ones and did the binns, tanami/simpson....after the Binns , it looked like the picture above, but after the simpson, it was cracking along the sidewalls. Made it home but not by much, went flat on its own a month later.

But what brand of tyres were they?

I know a lot of people buy cheap tyres for there van.

Yes I have heard of treat failure, but only on the cheaper non name brands

I had brand new tyres fitted to our van in Adelaide before a trip to Darwin. i had a tread come away from the case before Katherine so don't think new tyres are the best thing. A passerby thought i had recaps on due to the way it seperated. Warranty replacement at Katherine was more money than buying new from Adelaide. I'd buy the tyres a few years old as they harden up a little and seem to wear better than the green new ones.

I’ve got a mate who stores tyres for a few years to harden them up.
He swears he gets better mileage from them.
But he is not a 4WD person and doesn’t get off the bitumen.
I think this is dangerous practice as the rubber gets hard unable to flex on impact.
I had another mate who rolled his caravan when had 2 tyres blow at the same time.
This was on bitumen and I suspect he had ordinary car tyres or they too old.

Back in the 60's I knew a log truck owner who used to buy a full set of new tyres not recaps and store them under his house in the dark to harden them.

Agree! I don't buy bargains, but am prepared to pay for quality tyres that are less than 12 months old. After all, a couple of hundred bucks more is insignificant compared to the potential trouble it could cost you when your tyres let you down.

Dave
Agree fully

Core
l've always bought well known brands for that reason.

Murray

I have some different views.
I understand that the enemy of tyres is Ozone more than UV. Tyres are full of carbon black which is the best protection against UV that you could think of. Wrapping them will reduce ozone exposure, but keeping them in the dark will have relatively little effect.

And load rating is not in itself something that would cause a hard ride, in my view.
The tyres on the OKA are load rating 148, but I would not describe them as giving a hard ride. They have relatively thin walls and just a single sidewall ply. They are also a large section, so pressures, while high (to carry the load), are not extreme.
Heavy wall construction, high tyre pressures and low profiles certainly will give a hard ride though.
Cheers,
Peter
OKA196 motorhome

.
In have an even further view........
Certainly UV, Ozone, sunlight, oxygen, chlorine and lots of other atmospheres may affect the tyre but even without such exposures the rubber will harden just with the passage of time.

Rangiephil's "8 year old BFG ATKOs" which he has stored in darkness may not exhibit cracks etc and may appear fine but it is likely that they have hardened somewhat and could possibly produce cracking when put into service.

I am inclined to agree with the last two posts above. The pic I posted earlier of the hardened tyre which rapidly chipped badly on a rock track (which had little impact on younger tyres of the same type on the same vehicle at the same time) had always been fully covered by a lightproof black PVC cover, so at 6 years old it was not UV which had caused it to harden & deteriorate.

.
Yes Cuppa. It's not just tyres that are affected. Look at any rubber product...... they all harden and deteriorate with time. Exposure to light, UV, heat and many other things simply accelerates the process.

Except almost none of these "rubber" products are actually rubber any more, they are various other synthetic materials (plastics), each with their own strengths and weaknesses.
Cheers,
Peter
OKA196 motorhome

.
Yes Peter, I should think most people realise that.
But like Peanut Butter, the word 'rubber' has become generic for materials with similar 'rubbery' properties. And like natural rubber, most of these suffer from the same degregation with time and environmental affects.

VERY interesting Allan, esp this bit:
"Although tyres contain anti-oxidising chemicals to slow this process down, these only work when the tyres are moving."

I know nothing about the chemistry and strange things happen at molecular levels but that sounds like a combo of hocus pocus and straight out bs to me. A (very) quick search found no corroboration of Uniroyal's claim.

Michelin has a different view:
Michelin tyres are not bananas

.
Baz,
Yeah, I know that sounds a bit "hocus pocus" but there may just be some truth in it. I searched far and found no other reliable wisdom. Plenty of opinions from tyre sellers and forums but nothing scientific or from a reputable source. It seems to parallel the situation of an assembled bearing being rotated from time-to-time in order to redistribute the lubricant.

However, something in Uniroyal's expression rang a distant bell for me. Several times in my working life I had reason to replace a rubber component of an appliance and found that the one we had on the store shelf, that had been purchased as a spare at the same time we purchased the appliance, was in fact deteriorated and hardened even more than the one we were replacing that had been in constant service for a few years. It caused me to speculate on the possibility of 'static deterioration' compared to 'dynamic deterioration' but I was busy and had no time to conduct an investigation. I have also observed the hardening of rubber components that degraded, even though static in use, such as seals.

I do have some background in 'plastics' manufacture, even styrene butadiene as used in tyres, but not to the level of a qualified chemical engineer. I can see that Uniroyal's expression may have some validity but I could not hope to discuss it in any depth.
In any case, I can see no reason why I would store tyres for years at a time so am not very motivated to find a valid conclusion to the 'storage' subject.

DISCLAIMER: The use of the word "rubber" in the above narrative is intended to include both 'natural rubber' and 'synthetic rubber' and any other form or type of 'rubber' that you can think of.

I recall Collyn Rivers talking about this issue of unused tyres deteriorating due to internal oxidation citing this as the cause for blowouts at beginning of RV trips being far more common in vehicles which had sat unused for long periods. I found this reference online, but recall him having gon into greater detail.

MYTH: Tyres wear out but their age is less important.

REALITY: Tyre makers recommend replacing tyres after six or seven years regardless of use or otherwise. All tyres accumulate degrading atmospheric components resulting in their oxidising internally. Regular driving ‘pumps’ the damaging oxidation out of the tyre’s structure. But, unless done, tyres deteriorate until unusable. Never buy a new tyre without checking its date of manufacture. See pic on page 95 for how to tell.

https://wanderer.cmca.net.au/Article/Display/d4b34356-e8c8-4688-a673-86a1223df9fa

I suppose it's possible that a rotating tyre under pressure and load *might* stay more supple than a long-term stored tyre but I very much doubt that oxidation can be "pumped" out of a tyre as he claims Cuppa.

No idea if it has credibility but fwiw I just found this.
The Science of Tire Aging

Extract follows, the "Usage" bit apparently confirming Uniroyal's claim.

The Science of Aging
“Tires are primarily degrading from the inside-out, due [to] permeation and reaction of the pressurized oxygen within the tire structure, with rates proportional to temperature.” - Summary of NHTSA Tire Aging Test Development Research

Tire aging is an issue of oxidation. As rubber is exposed to oxygen, it dries out and becomes stiffer, leading to cracking. The issue is primarily about how the inner, “wedge” layers of rubber oxidize.

The stiffening and cracking of aged rubber can lead to the inner layers of the tire delaminating from the steel belts rather than flexing with the steel as the tire rolls underweight.

There are essentially four major factors that determine how fast a tire will age:

The Inner Liner:
The inner liner of any tire is a specialized butyl rubber compound that is designed to be impermeable to air to keep the air inside the tire where it belongs. No inner liner is entirely waterproof, so some air will always leak slowly through the liner due to osmosis. The quality of the inner liner determines just how much air leaks through, and therefore how fast the inner structure of the tire is exposed to oxygen.

Oxygen Concentration:
It's pretty easy to see that oxidation rates will increase when the oxygen concentration is higher. What this means is that a tire that is mounted and filled with compressed air will age much faster than a tire that is just being stored, because the air pressure is orders of magnitude higher in a filled tire, and more oxygen will permeate through the liner.

Heat:
Oxidation of rubber occurs much faster under high heat than low heat. In essence, heat increases both the permeability and reactivity of oxygen, making it both easier for oxygen to get through the inner liner and easier for it to react with the rubber inside the tire.

Usage:
When a tire is driven, the pressure and flexing motion circulate the internal oils through the rubber. These oils lubricate the internal rubber and keep it from drying and stiffening. So tires that are used less are often more vulnerable to aging effects.

There are quite a few scientific papers on "rubber" degradation but those I found required a subscription. Suffice to say that newer is (ought to be) significantly better than older, but that's common knowledge.

Pumped was in inverted commas, so quite what the intended meaning was who knows, but there does seem to be consistency in that a tyre fitted & in use fares better than an inflated but unused one. Perhaps we might all be better off carrying our spares fitted but uninflated?