Replacement of older tyres?

[pfillery]

Was told in no uncertain terms by a tyre place last week that tyres have a lifespan of 5 - 6 years and that even if the tread is good (which mine are) that they should be chucked and replaced after 5 or 6 years.

Has anyone else heard this and is there any truth to it? Obviously if the sidewalls were cracked, the tread crumbling and the things falling apart or going flat, you would replace them, but do they pose any safety or legal risks if they are 12 years old (as my set are) and still in good order, or in the case of my spare, one of the 35 year old original tyres? The spare has a few nicks and cracks as would be expected from and old one but still has over 5mm of tread and, as the name suggests, is a spare only.

Any thoughts on this?

[101RRS]

Is totally true - tyres may look OK and are probably safe but they will have started to go hard and no longer perform as specified. What is the best before date - 5-6-10years - is not actually specified but is in that order.

There is a code on the tyre giving its build date.

Garry

[trobbo]

the rubber will harden and so will not perform as well. This in turn will affect things like sidewalls with a risk of blow out as the tyre flexes, and loss of traction due to hardening of the compound.

Having said that I ran a set of BFG all terains until they were worn out. Probably about 12 years old or so.

[isuzurover]

The 6 year rule is a manufacturer's reccommendation. From the info I have found it is not law.

So it is up to you to decide if the tyres are still fit for service of not.



How old is too old?

This is a subject of much debate within the tyre industry and no tyre expert can tell exactly how long a tyre will last. However, on the results of experience many tyre companies, including Bridgestone, warrant their tyres against manufacturing and material defects for five years from the date of manufacture. Based on their understanding a number of vehicle manufacturers are now advising against the use of tyres that are more than six years old due to the effects of ageing.
Tyre Ageing Mechanism

There are three main mechanisms of tyre ageing. The first involves rubber becoming more brittle. Sulphur is used to link rubber molecules together during vulcanisation with the application of heat and pressure, giving the rubber its useful elastic properties and strength. As the tyre absorbs energy in the form of light, heat or movement the tyre continues to vulcanise. This ongoing vulcanisation causes the rubber to become stiffer and more brittle.

The second mechanism of tyre ageing is oxidation involving oxygen and ozone from the air compromising the strength and elasticity of the rubber and the integrity of the rubber to steel bond. Basically heat and oxygen cause cross linking between polymer chains (causing the rubber to harden) and scission of polymer chains (leading to reduced elasticity).

Thirdly, breakdown of the rubber to steel-belt bond will occur due to water permeating through a tyre and bonding with the brass plate coating on steel belts. This causes the steel to rubber bond to weaken leading to reduced tyre strength and reduced heat resistance. If compressed air used for inflation is not completely dry, tyre strength will be affected over time. Even unused tyres will become more brittle, weaker and less elastic with exposure to water, air, heat and sunlight.
Warning signs

Regardless of their age tyres should be replaced if they show significant crazing or cracking in the tread grooves or sidewall (Figure 3&4) and or bulging of the tread face or sidewall. All tyres, especially unused spare tyres, should be inspected periodically to determine their suitability for service. If there is any question about a tyre's suitability please consult your local Bridgestone Tyre Centre expert.

[dolphint]

I had a set of 9 year old HanKooks and just last month 3 of them let go internally developing large eggs in the tread, all within a week of each other. Up til then, I thought they were great tyres, got more than 100k out of them, might be something in what that tyre mob says

[JDNSW]

Tyres will undoubtedly deteriorate from the day they are made - the question is, at what rate? And howbad do they have to get before this deterioration means they should be replaced?

Despite what the tyre manufacturers (and sellers) have to say, the answer to these questions will not be a neat, simple number - whether it is 6,8,10 years or whatever. The answer to the first question will depend on the temperatures encountered, the exposure to UV, etc. And how much deterioration is acceptable will depend on another set of variables, including how much the original spec is above what is needed, and what the usage of the tyres will be.

I know that I would be very careful if I was told that my tyres need to be replaced after six years by someone who stands to make a lot of money by selling me the replacement tyres! On the other hand, if he pointed out cracks, chipped treads, bulges etc, I would be much more receptive. In over fifty years of driving, I cannot recall a single case of a tyre failure that could in any way be attributed directly to age, although I suspect that the ease with which I staked a tractor tyre may have had something to do with this (tyre was probably forty years old!). On the other hand, I have had tyres fail with as little as 1000km and less than a month age (developed sidewall blisters, had never been run except at specified pressure - all five tyres on a new car, including spare!).

John

[101RRS]

John,

It was on both A Current Affair and Today Tonight about two years ago - so it must be true :o - you cannot dispute respected sources like these programs :D.

Garry

[PhilipA]

I think you should take it "with a pinch of salt"
I ran a set of TA Kos over the Oodnadatta Strezlecki and then the Savannah Way at 9 years old .

When I returned from the 8k trip, I noticed the rears had some very fine cracks around the raised line on the sidewall and I then replaced them.
They probably got hotter than the fronts as I reduced pressures for the dirt.
I bought a set of cheap Japanese Bridgestones for my car then noticed they were 6 years old. They performed AFAIK perfectly and didn't seem any different to a fresh tyre. They had been stored in the dark and in their protective wrapping though, and I think the exposure to sunlight may be a big ageing factor.
Regards Philip A

[mark2]

My BFG M/T's are now 11 years old and show no visible defects. I have lost a lug or two on some rocky tracks but consider them still serviceable with about 8mm tread depth remaining. They are stored in the shade - I've seen younger tyres which are in the sun all day develop sidewall cracking.

[THE BOOGER]

The only time I have had problems that were age related was over 20 years ago with a smash repair loan car the tyres had gone hard and had very little grip on the road it put a patrolman I was working with in hostpital when he hit a pole car just wanted to go in a straight line:(. With modern tyres particuarly the new silicon ones I would have thought they could make them last longer even when parked in the sun all the time:D but then they couldnt tell us to change them after 5 or 6 years could they:p

[Blknight.aus]

there is truth in it however there are many factors that contribute.

generally unless you keep a stack of tyres around or leave your car parked in the sun without moving it for months at a time its not going to be a problem. Ironically.

cheap tyres that deteriorate fast also tend to wear out fast
expensive tyres that last for ages also take ages to wear out.

the best clue as to the condition of the rubber of your tyre will be typically at the edges of the tread block on the shoulder, once they start to crack at the joints your rubber is basically dying and should be repalced.

[Dougal]

The outfits that sell new tyres have a financial interest in making you replace tyres that don't need it.
I have bought "brand new" tyres that were 3 years old. If that tyre dealer beleived in a 6 year life then he should have given me 50% discount.:angel:

Tractor tyres are the oldest ones I have experience with, they start to fail structurally around the 30 year mark. These sit in the weather 24-7 and so age much faster than car tyres.

If you're worried about the outer surface hardening, that's more a lack of use problem than an age problem.

[isuzurover]

If you're worried about the outer surface hardening, that's more a lack of use problem than an age problem.

I have found that long highway trips in hot weather definitely make tyres harder. The current tyres on my 110 have now done 3 trips across the Nullarbor among others. I have noticed that they are significantly harder after each trip.

But I agree with everything else. I have only ever replaced tyres due to wear or defects, not age. I have only once had a tyre fail completely on me, and it was only 2 years old.

[gromit]

I replaced the original Michelin ( X 4x4?) tyres on my Defender about 9-10 years ago because they squealed when taking roundabouts a touch too fast, must have been because the compound had gone off.
Replaced them with a set of Michelin XPC's and 9 years down the track they have started squealing on roundabouts so I guess the compound has hardened on these.

I have a few old motorbikes with tyres that are at least 30 -40 years old with no cracking or signs of deterioration, one is an outfit so I wouldn't worry about the tyre hardness but the solo's I might consider something new & grippy......



Colin

[pfillery]

Would it be fair to assume that there would be a difference between a sedan car tyre with a low ply rating and a light truck tyre? Mine are 14 ply which is more than even a light truck tyre.

Is there anything that can be used to treat tyres that are going to be weather exposed? ie the spare on a bonnet mount? Not to make it look pretty (although...) but to stop the rubber cracking.

[87County]

Would it be fair to assume that there would be a difference between a sedan car tyre with a low ply rating and a light truck tyre? Mine are 14 ply which is more than even a light truck tyre.

Is there anything that can be used to treat tyres that are going to be weather exposed? ie the spare on a bonnet mount? Not to make it look pretty (although...) but to stop the rubber cracking.

plenty of people have a vinyl cover on their rear door mounted spare - if you are concerned, consider putting one of those type of covers on your bonnet mounted spare.....

[101RRS]

From Wikipedia

Dangers of aged tires

Research and tests show that as tires age, they begin to dry out and become potentially dangerous, even if unused. Aged tires may appear to have similar properties to newly manufactured tires, but rubber degrades over time, and once the vehicle is traveling at high speeds (i.e. on a Freeway - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Mergefrom.svg" class="image"><img alt="Mergefrom.svg" src="http://upload.wikimedia.org/wikipedia/commons/thumb/0/0f/Mergefrom.svg/50px-Mergefrom.svg.png"@@AMEPARAM@@commons/thumb/0/0f/Mergefrom.svg/50px-Mergefrom.svg.png) the tread could peel off, leading to severe loss of control. In tropical climates, such as Singapore, tires degrade sooner than in temperate climates, and more care should be taken in these climates to ensure that tires do not fail.[Wikipedia:Citation needed - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Webcomic_xkcd_-_Wikipedian_protester.png" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/3/31/Webcomic_xkcd_-_Wikipedian_protester.png/300px-Webcomic_xkcd_-_Wikipedian_protester.png"@@AMEPARAM@@commons/thumb/3/31/Webcomic_xkcd_-_Wikipedian_protester.png/300px-Webcomic_xkcd_-_Wikipedian_protester.png] Also, tires on seldom-used trailers are at the greatest risk of age-failure, but some tires are built to withstand idleness, usually with nylon reinforcement.
Many automakers recommend replacing tires after six years, and several tire manufacturers (Bridgestone - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Bridgestone_logo.svg" class="image" title="The Bridgestone Corporation Company logo"><img alt="The Bridgestone Corporation Company logo" src="http://upload.wikimedia.org/wikipedia/en/thumb/6/6d/Bridgestone_logo.svg/200px-Bridgestone_logo.svg.png"@@AMEPARAM@@en/thumb/6/6d/Bridgestone_logo.svg/200px-Bridgestone_logo.svg.png, Michelin - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Michelin.svg" class="image" title="Michelin"><img alt="Michelin" src="http://upload.wikimedia.org/wikipedia/en/thumb/4/44/Michelin.svg/225px-Michelin.svg.png"@@AMEPARAM@@en/thumb/4/44/Michelin.svg/225px-Michelin.svg.png) have called for tires to be removed from service 10 years after the date of manufacture. However, an investigative report by Brian Ross on American Broadcasting Company - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:American_Broadcasting_Company_Logo_2007.png" class="image"><img alt="American Broadcasting Company Logo 2007.png" src="http://upload.wikimedia.org/wikipedia/en/thumb/2/21/American_Broadcasting_Company_Logo_2007.png/150px-American_Broadcasting_Company_Logo_2007.png"@@AMEPARAM@@en/thumb/2/21/American_Broadcasting_Company_Logo_2007.png/150px-American_Broadcasting_Company_Logo_2007.png's 20/20 (http://en.wikipedia.org/wiki/20/20) news magazine found that many major retailers such as Goodyear Tire and Rubber Company - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Goodyear_logo.svg" class="image" title="Goodyear logo"><img alt="Goodyear logo" src="http://upload.wikimedia.org/wikipedia/en/thumb/3/35/Goodyear_logo.svg/200px-Goodyear_logo.svg.png"@@AMEPARAM@@en/thumb/3/35/Goodyear_logo.svg/200px-Goodyear_logo.svg.png, Wal-Mart (http://en.wikipedia.org/wiki/Wal-Mart), and Sears - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Text_document_with_red_question_mark.svg" class="image"><img alt="Text document with red question mark.svg" src="http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/Text_document_with_red_question_mark.svg/40px-Text_document_with_red_question_mark.svg.png"@@AMEPARAM@@commons/thumb/a/a4/Text_document_with_red_question_mark.svg/40px-Text_document_with_red_question_mark.svg.png were selling tires that had been produced six or more years ago. Currently, no law for aged tires exists in the United States.


Also from Wikipedia - Tires or Tyres


The Oxford English Dictionary - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Question_book-new.svg" class="image"><img alt="Question book-new.svg" src="http://upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png"@@AMEPARAM@@en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png suggests that the word derives from "attire",[1] (http://en.wikipedia.org/wiki/Tire#cite_note-fowler-0) while other sources suggest a connection with the verb "to tie".[2] (http://en.wikipedia.org/wiki/Tire#cite_note-eb-1) From the 15th to the 17th centuries the spellings tire and tyre were used without distinction;[1] (http://en.wikipedia.org/wiki/Tire#cite_note-fowler-0) but by 1700 tyre had become obsolete and tire remained as the settled spelling.[1] (http://en.wikipedia.org/wiki/Tire#cite_note-fowler-0) In the UK, the spelling tyre was revived in the 19th century for pneumatic tires, though many continued to use tire for the iron variety. The Times - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:TheTimes.png" class="image"><img alt="TheTimes.png" src="http://upload.wikimedia.org/wikipedia/en/thumb/f/fe/TheTimes.png/220px-TheTimes.png"@@AMEPARAM@@en/thumb/f/fe/TheTimes.png/220px-TheTimes.png newspaper in Britain was still using tire as late as 1905.[3] (http://en.wikipedia.org/wiki/Tire#cite_note-2) The Encyclopædia Britannica Eleventh Edition - Wikipedia, the free encyclopedia@@AMEPARAM@@/wiki/File:Encyclopaedia_Britannica_1911.svg" class="image"><img alt="" src="http://upload.wikimedia.org/wikipedia/commons/thumb/0/02/Encyclopaedia_Britannica_1911.svg/300px-Encyclopaedia_Britannica_1911.svg.png"@@AMEPARAM@@commons/thumb/0/02/Encyclopaedia_Britannica_1911.svg/300px-Encyclopaedia_Britannica_1911.svg.png states that "[t]he spelling 'tyre' is not now accepted by the best English authorities, and is unrecognized in the US",[2] (http://en.wikipedia.org/wiki/Tire#cite_note-eb-1) while A Dictionary of Modern English Usage - Wikipedia, the free encyclopedia of 1926 says that "there is nothing to be said for 'tyre', which is etymologically wrong, as well as needlessly divergent from our own [sc. British] older & the present American usage".[1] (http://en.wikipedia.org/wiki/Tire#cite_note-fowler-0) However, over the course of the 20th century tyre became established as the standard British spelling.

[101RRS]

wow - all those pics were not in the text when I posted it up:o

[87County]

wow - all those pics were not in the text when I posted it up:o

some here say that "without pics" - it didn't happen :)