tire ageing questions answered

[1939mgtb]

Hello all. Once again, I called on my friend who is a tire engineer with a major tire manufacturer. I asked about the ageing issue with tires, and I attach his comments below. I call your attention to the storage of new tires awaiting delivery to tire dealers.... Best, Ray Sent: Monday, August 08, 2005 8:58 AM Subject: RE: Facts about tires Ray, I don't think anyone knows how long a tire can last.....because too many things, including the original technology employed, will influence durability and resistance to deterioration. The tire industry and NHTSA are currently looking at ageing factors due to potential legal liability issues if a tire fails in service due to age-related issues and to establish a "best practice" if such a thing can be determined. A couple of Original Equipment car companies have initiated comments in their new car literature recommending tires be used no longer than 6 years, though I personally know of no technical foundation for this policy and I suspect it has a "hoped for" legal absolution for them. It is currently common practice in the replacement tire marketplace to sell "new" tires that have been in dealer or manufacturer warehouses for 3-4 or more years which is not a wonderful habit ... but it has supported the virtually "trouble-free" perspective earned by today's tires. We all know people that are using or have used 20, 25, even 30 year old tires with no problems.....I am one of them! Tires can work at almost any age if used gently, inflated properly, kept undamaged, and inspected often. If the tires have good tread depth, no cuts or localized bulges that indicate reinforcement damage, and no surface cracking over about 1/16" deep (evenly distributed vs. "concentrated" areas of cracking that indicate non-uniform stress in that area) then they may work OK. However, it is likely that an average hobbyist may not recognize when some of the noted visual conditions have begun developing and/or accelerating which means 2 things: 1. Constant inspection/evaluation is a must with all tires, especially old tires. Ideally constant means virtually at the beginning and end of every substantial usage. 2. Obviously, new tires are less likely to deliver any unexpected deterioration and they can relieve a user's anxiety and somewhat lessen the inspection routine. Polyester and nylon bias tires, common until the early 70's, have a body construction that is rather "constantly" stressed from one side of the wheel to the other because the all of the reinforcing plies are basically doing the same job. Radial tires, with their distinctly different body and belt plies have an inherent stress location under the tread edge where the radial plies (that go from side-to-side) meet the largely circumferential belts that are only under the tread. As a result of the construction differences, it is my opinion that bias tires age more gracefully than radials which will almost always undergo some internal deterioration at the stressed belt/body junction. Modern radials are designed to accommodate/compensate for their belt edge stresses, but under rigorous use in an aged condition I believe that radials may be more likely to have reinforcement issues than bias tires. When considering tires that are in the high-performance arena, all of the prior discussion is magnified. Because high speed rated tires are designed for that purpose, the constructions are generally more robust in their protection against stress-induced issues, but deterioration can likewise have more sudden impact because you cannot be looking at them at 100+ mph. In either construction, a tire's ability to tell you when it has a problem is dependent on the user's sensitivity. If a smooth-running tire starts vibrating in mid-life, something has changed. Vibrations can be a sign of a thrown wheel weight or a separation of tire components or a mechanical problem .... but operating with them involves risk. A tire that makes a sound w/each wheel revolution likely has a component separation, braking flat-spot, or localized damage. Any tire with a localized bulge or crack has something unique going on in that location and it needs attention. Right away. Treat a tire like a friend and try to pay attention to any symptoms and you'll get along better .....longer. To maximize a tire's useful life, all of the noted maintenance practices regarding inspection, inflation, and damage prevention are very important. Additional steps that can slow deterioration would include: 1. Storage in the dark. Sunlight attacks and cracks rubber in all external parts of the tire 2. Keep tires away from electrical motors, air ionizers, electronic air cleaners, etc. All electrical motors also create ozone gas that promotes surface cracking. 3. Don't allow gas or oil contact w/tires as the rubber compounds all include oil in their original formulas so excess oil naturally wants to enter into the cured rubber and start softening it up again which can cause severe deterioration and component separations. 4. Don't use petroleum-based (most of them unfortunately!) tire shiners/dressings as their cleaning action can be twofold: - Oils penetrate the surface just as described in #4 and chemically damage the surface - Light oil solvents remove waxes and anti-oxidants designed into the rubber to prevent surface ozone cracking. These rubber compound ingredients are what cause the gray or brown waxy build-up on tire sidewalls and it is their to protect the rubber. These protective materials are designed to move to the surface as tires are exercised; it is just a shame they are unattractive. In used tire inspections it is very common to see tires with extremely different levels of cracking on the sidewalls because one of them has been routinely "cleaned". These observations are purely my own thoughts and observations after 45 years as a hobbyist and 35 in the tire industry. I must stress that the tremendous variability in tire technology between manufacturers, technology over time, tire usage conditions, and maintenance practices could bring other folks with my same experience to somewhat different conclusions. Tires are not machined, easily predictable products like many other car components. Instead, they are assembled from many pieces of dissimilar materials into stretchy things that transfer all of a car's dynamic capabilities to the road while being routinely abused and ignored.. Hence, there is no advice that can ever apply perfectly to every tire/vehicle/owner situation ..... either new or old! Mike -----Original Message----- Subject: Fw: Facts about tires Mike, More stuff on the MG group about tire aging. As a past owner of Bitchitlin XX's, I have an opinion, but not couched in tire engineering. Here's the question: How long does a tire last with respect to aging? What effects the tire while stored? Best, Ray "Conlige suspectos semper habitos!"

----- Original Message ----- From: "Mike Duvall" duvallcom@sbcglobal.net> To: mg-t@autox.team.net> Sent: Thursday, August 04, 2005 12:43 PM Subject: Facts about tires > Anyone have any evidence of the age of a tire being a problem or is this > speculation?. I can understand a tire from the 60 or 70s cracking and > getting old but tires made in the 80s and 90s have to be made of better > materials. These marketers like to put the fear of God into you to sell > you anything new. > > Please don't respond with opinion and your life is at stake and all the > rhetoric, If anyone can reference a location on facts, I would appreciate > it....(preferably not a manufacturer's site) Something independent... > > Mike [Non-text portions of this message have been removed]

[Tom]

This is very interesting. The tires that came with TC1197 were so old they had "Made in England" stamped on them. Even though they had good tread left, I replaced them with a new set of Dunlops because of their age. Oh well. Tom Gill

----- Original Message ----- From: "1939mgtb" 1939mgtb@comcast.net> To: "mgtabc" mg-tabc@yahoogroups.com> Sent: Wednesday, August 10, 2005 12:22 PM Subject: [mg-tabc] tire ageing questions answered > Hello all. Once again, I called on my friend who is a tire engineer with > a major tire manufacturer. I asked about the ageing issue with tires, and > I attach his comments below. I call your attention to the storage of new > tires awaiting delivery to tire dealers.... > Best, > Ray > > Sent: Monday, August 08, 2005 8:58 AM > Subject: RE: Facts about tires > > > Ray, > > I don't think anyone knows how long a tire can last.....because too many > things, including the original technology employed, will influence > durability and resistance to deterioration. > > The tire industry and NHTSA are currently looking at ageing factors due > to potential legal liability issues if a tire fails in service due to > age-related issues and to establish a "best practice" if such a thing > can be determined. A couple of Original Equipment car companies have > initiated comments in their new car literature recommending tires be > used no longer than 6 years, though I personally know of no technical > foundation for this policy and I suspect it has a "hoped for" legal > absolution for them. It is currently common practice in the replacement > tire marketplace to sell "new" tires that have been in dealer or > manufacturer warehouses for 3-4 or more years which is not a wonderful > habit ... but it has supported the virtually "trouble-free" perspective > earned by today's tires. > > We all know people that are using or have used 20, 25, even 30 year old > tires > with no problems.....I am one of them! Tires can work at almost any age > if used gently, inflated properly, kept undamaged, and inspected often. > If the tires have good tread depth, no cuts or localized bulges that > indicate reinforcement damage, and no surface cracking over about 1/16" > deep (evenly distributed vs. "concentrated" areas of cracking that > indicate non-uniform stress in that area) then they may work OK. However, > it is likely that an average hobbyist may not recognize when some of the > noted visual conditions have begun developing and/or accelerating which > means 2 things: > 1. Constant inspection/evaluation is a must with all tires, especially > old tires. Ideally constant means virtually at the beginning and end of > every substantial usage. > 2. Obviously, new tires are less likely to deliver any unexpected > deterioration and they can relieve a user's anxiety and somewhat > lessen the inspection routine. > > Polyester and nylon bias tires, common until the early 70's, have a body > construction that is rather "constantly" stressed from one side of the > wheel to the other because the all of the reinforcing plies are > basically doing the same job. Radial tires, with their distinctly > different body and belt plies have an inherent stress location under the > tread edge where the radial plies (that go from side-to-side) meet the > largely circumferential belts that are only under the tread. As a result > of the construction differences, it is my opinion that bias tires age > more gracefully than radials which will almost always undergo some > internal deterioration at the stressed belt/body junction. Modern > radials are designed to accommodate/compensate for their belt edge > stresses, but under rigorous use in an aged condition I believe that > radials may be more likely to have reinforcement issues than bias tires. > > When considering tires that are in the high-performance arena, all of > the prior discussion is magnified. Because high speed rated tires are > designed for that purpose, the constructions are generally more robust > in their protection against stress-induced issues, but deterioration can > likewise have more sudden impact because you cannot be looking at them > at 100+ mph. > > In either construction, a tire's ability to tell you when it has a > problem is dependent on the user's sensitivity. If a smooth-running tire > starts vibrating in mid-life, something has changed. Vibrations can be a > sign of a thrown wheel weight or a separation of tire components or a > mechanical problem .... but operating with them involves risk. A tire > that makes a sound w/each wheel revolution likely has a component > separation, braking flat-spot, or localized damage. Any tire with a > localized bulge or crack has something unique going on in that location > and it needs attention. Right away. Treat a tire like a friend and try to > pay > attention to any symptoms and you'll get along better .....longer. > > To maximize a tire's useful life, all of the noted maintenance practices > regarding inspection, inflation, and damage prevention are very > important. Additional steps that can slow deterioration would include: > > 1. Storage in the dark. Sunlight attacks > and cracks rubber in all external parts of the tire > 2. Keep tires away from electrical motors, air ionizers, electronic air > cleaners, etc. All electrical motors also create ozone gas that promotes > surface cracking. > 3. Don't allow gas or oil contact w/tires as the rubber compounds all > include oil in their original formulas so excess oil naturally wants to > enter into the cured rubber and start softening it up again which can > cause severe deterioration and component separations. > 4. Don't use petroleum-based (most of them unfortunately!) tire > shiners/dressings as their cleaning action can be twofold: > - Oils penetrate the surface just as described in #4 and chemically > damage the surface > - Light oil solvents remove waxes and anti-oxidants designed into the > rubber to prevent surface ozone cracking. These rubber compound > ingredients are what cause the gray or brown waxy build-up on tire > sidewalls and it is their to protect the rubber. These protective > materials are designed to move to the surface as tires are exercised; it > is just a shame they are unattractive. In used tire inspections it is > very common to see tires with extremely different levels of cracking on > the sidewalls because one of them has been routinely "cleaned". > > These observations are purely my own thoughts and observations after 45 > years as a hobbyist and 35 in the tire industry. I must stress that the > tremendous variability in tire technology between manufacturers, > technology over time, tire usage conditions, and maintenance practices > could bring other folks with my same experience to somewhat different > conclusions. Tires are not machined, easily predictable products like > many other car components. Instead, they are assembled from many pieces > of dissimilar materials into stretchy things that transfer all of a > car's dynamic capabilities to the road while being routinely abused and > ignored.. Hence, there is no advice that can ever apply perfectly to > every tire/vehicle/owner situation ..... either new or old! > > Mike > > -----Original Message----- > Subject: Fw: Facts about tires > > Mike, > More stuff on the MG group about tire aging. As a past owner of > Bitchitlin XX's, I have an opinion, but not couched in tire engineering. > Here's the question: How long does a tire last with respect to aging? > What effects the tire while stored? > Best, > Ray > > "Conlige suspectos semper habitos!" > ----- Original Message ----- > From: "Mike Duvall" duvallcom@sbcglobal.net> > To: mg-t@autox.team.net> > Sent: Thursday, August 04, 2005 12:43 PM > Subject: Facts about tires > > >> Anyone have any evidence of the age of a tire being a problem or is > this >> speculation?. I can understand a tire from the 60 or 70s cracking and > >> getting old but tires made in the 80s and 90s have to be made of > better >> materials. These marketers like to put the fear of God into you to > sell >> you anything new. >> >> Please don't respond with opinion and your life is at stake and all > the >> rhetoric, If anyone can reference a location on facts, I would > appreciate >> it....(preferably not a manufacturer's site) Something independent... >> >> Mike > > > [Non-text portions of this message have been removed] > > > > > Yahoo! Groups Links > > > > > > >

[Robin Montgomery]

Will the authorities give any special attention to a combination of new inner tubes with old covers? Does this give us any additional security over and above a tubeless tyre. Regards, Robin Montgomery CT,USA _________________________________ -----Original Message----- From: Tom [mailto:tgill2@tampabay.rr.com] Sent: Thursday, August 11, 2005 10:55 AM To: 1939mgtb; mgtabc Subject: Re: [mg-tabc] tire ageing questions answered This is very interesting. The tires that came with TC1197 were so old they had "Made in England" stamped on them. Even though they had good tread left, I replaced them with a new set of Dunlops because of their age. Oh well. Tom Gill

----- Original Message ----- From: "1939mgtb" 1939mgtb@comcast.net> To: "mgtabc" mg-tabc@yahoogroups.com> Sent: Wednesday, August 10, 2005 12:22 PM Subject: [mg-tabc] tire ageing questions answered > Hello all. Once again, I called on my friend who is a tire engineer with > a major tire manufacturer. I asked about the ageing issue with tires, and > I attach his comments below. I call your attention to the storage of new > tires awaiting delivery to tire dealers.... > Best, > Ray > > Sent: Monday, August 08, 2005 8:58 AM > Subject: RE: Facts about tires > > > Ray, > > I don't think anyone knows how long a tire can last.....because too many > things, including the original technology employed, will influence > durability and resistance to deterioration. > > The tire industry and NHTSA are currently looking at ageing factors due > to potential legal liability issues if a tire fails in service due to > age-related issues and to establish a "best practice" if such a thing > can be determined. A couple of Original Equipment car companies have > initiated comments in their new car literature recommending tires be > used no longer than 6 years, though I personally know of no technical > foundation for this policy and I suspect it has a "hoped for" legal > absolution for them. It is currently common practice in the replacement > tire marketplace to sell "new" tires that have been in dealer or > manufacturer warehouses for 3-4 or more years which is not a wonderful > habit ... but it has supported the virtually "trouble-free" perspective > earned by today's tires. > > We all know people that are using or have used 20, 25, even 30 year old > tires > with no problems.....I am one of them! Tires can work at almost any age > if used gently, inflated properly, kept undamaged, and inspected often. > If the tires have good tread depth, no cuts or localized bulges that > indicate reinforcement damage, and no surface cracking over about 1/16" > deep (evenly distributed vs. "concentrated" areas of cracking that > indicate non-uniform stress in that area) then they may work OK. However, > it is likely that an average hobbyist may not recognize when some of the > noted visual conditions have begun developing and/or accelerating which > means 2 things: > 1. Constant inspection/evaluation is a must with all tires, especially > old tires. Ideally constant means virtually at the beginning and end of > every substantial usage. > 2. Obviously, new tires are less likely to deliver any unexpected > deterioration and they can relieve a user's anxiety and somewhat > lessen the inspection routine. > > Polyester and nylon bias tires, common until the early 70's, have a body > construction that is rather "constantly" stressed from one side of the > wheel to the other because the all of the reinforcing plies are > basically doing the same job. Radial tires, with their distinctly > different body and belt plies have an inherent stress location under the > tread edge where the radial plies (that go from side-to-side) meet the > largely circumferential belts that are only under the tread. As a result > of the construction differences, it is my opinion that bias tires age > more gracefully than radials which will almost always undergo some > internal deterioration at the stressed belt/body junction. Modern > radials are designed to accommodate/compensate for their belt edge > stresses, but under rigorous use in an aged condition I believe that > radials may be more likely to have reinforcement issues than bias tires. > > When considering tires that are in the high-performance arena, all of > the prior discussion is magnified. Because high speed rated tires are > designed for that purpose, the constructions are generally more robust > in their protection against stress-induced issues, but deterioration can > likewise have more sudden impact because you cannot be looking at them > at 100+ mph. > > In either construction, a tire's ability to tell you when it has a > problem is dependent on the user's sensitivity. If a smooth-running tire > starts vibrating in mid-life, something has changed. Vibrations can be a > sign of a thrown wheel weight or a separation of tire components or a > mechanical problem .... but operating with them involves risk. A tire > that makes a sound w/each wheel revolution likely has a component > separation, braking flat-spot, or localized damage. Any tire with a > localized bulge or crack has something unique going on in that location > and it needs attention. Right away. Treat a tire like a friend and try to > pay > attention to any symptoms and you'll get along better .....longer. > > To maximize a tire's useful life, all of the noted maintenance practices > regarding inspection, inflation, and damage prevention are very > important. Additional steps that can slow deterioration would include: > > 1. Storage in the dark. Sunlight attacks > and cracks rubber in all external parts of the tire > 2. Keep tires away from electrical motors, air ionizers, electronic air > cleaners, etc. All electrical motors also create ozone gas that promotes > surface cracking. > 3. Don't allow gas or oil contact w/tires as the rubber compounds all > include oil in their original formulas so excess oil naturally wants to > enter into the cured rubber and start softening it up again which can > cause severe deterioration and component separations. > 4. Don't use petroleum-based (most of them unfortunately!) tire > shiners/dressings as their cleaning action can be twofold: > - Oils penetrate the surface just as described in #4 and chemically > damage the surface > - Light oil solvents remove waxes and anti-oxidants designed into the > rubber to prevent surface ozone cracking. These rubber compound > ingredients are what cause the gray or brown waxy build-up on tire > sidewalls and it is their to protect the rubber. These protective > materials are designed to move to the surface as tires are exercised; it > is just a shame they are unattractive. In used tire inspections it is > very common to see tires with extremely different levels of cracking on > the sidewalls because one of them has been routinely "cleaned". > > These observations are purely my own thoughts and observations after 45 > years as a hobbyist and 35 in the tire industry. I must stress that the > tremendous variability in tire technology between manufacturers, > technology over time, tire usage conditions, and maintenance practices > could bring other folks with my same experience to somewhat different > conclusions. Tires are not machined, easily predictable products like > many other car components. Instead, they are assembled from many pieces > of dissimilar materials into stretchy things that transfer all of a > car's dynamic capabilities to the road while being routinely abused and > ignored.. Hence, there is no advice that can ever apply perfectly to > every tire/vehicle/owner situation ..... either new or old! > > Mike > > -----Original Message----- > Subject: Fw: Facts about tires > > Mike, > More stuff on the MG group about tire aging. As a past owner of > Bitchitlin XX's, I have an opinion, but not couched in tire engineering. > Here's the question: How long does a tire last with respect to aging? > What effects the tire while stored? > Best, > Ray > > "Conlige suspectos semper habitos!" > ----- Original Message ----- > From: "Mike Duvall" duvallcom@sbcglobal.net> > To: mg-t@autox.team.net> > Sent: Thursday, August 04, 2005 12:43 PM > Subject: Facts about tires > > >> Anyone have any evidence of the age of a tire being a problem or is > this >> speculation?. I can understand a tire from the 60 or 70s cracking and > >> getting old but tires made in the 80s and 90s have to be made of > better >> materials. These marketers like to put the fear of God into you to > sell >> you anything new. >> >> Please don't respond with opinion and your life is at stake and all > the >> rhetoric, If anyone can reference a location on facts, I would > appreciate >> it....(preferably not a manufacturer's site) Something independent... >> >> Mike > > > [Non-text portions of this message have been removed] > > > > > Yahoo! Groups Links > > > > > > > Yahoo! Groups Links