Tire aging, rubber compound, when to replace?
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Tire aging, rubber compound, when to replace?
My tires have wear indicators and they are in good shape. But, do tires degrade with age and how does one determine if a tire should be replaced? Tire compound, construction and use/abuse contribute to a tire's useful life, IMHO, even if the rubber is not worn thin. What got thinking about all this is; car road tires are mileage rated. In motor sports, racing tires only last for a certain number of heat cycles. I don't expect retail bike tires to "go off" very quickly like car racing tires but how many seasons/years do bike tires generally last and continue to provide effective traction? Are certain "performance" road-bike tires last significantly less that the norm? What is the norm?
Thoughts?
Please reply.
Thoughts?
Please reply.
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I've seen lucky SOB's that get away with the ply complete worn thru and the inner tube is rolling on the road.
It's your bike and your safety. You shouldn't let others, especially strangers that don't really care if you die or not, to tell you when to replace something that can save your life.
If money is an issue, even a cheapie tire is better than some worn out dilapidated premium tire.
Having just one incident of a blown tire or tube is inconvenience enough to regret not having replaced it when you first thought about doing it.
I know folks that are so paranoid with their tires, they replace them every season regardless of how good they still might be. No wrong doing there.
If it bothers you, get new ones.
It's your bike and your safety. You shouldn't let others, especially strangers that don't really care if you die or not, to tell you when to replace something that can save your life.
If money is an issue, even a cheapie tire is better than some worn out dilapidated premium tire.
Having just one incident of a blown tire or tube is inconvenience enough to regret not having replaced it when you first thought about doing it.
I know folks that are so paranoid with their tires, they replace them every season regardless of how good they still might be. No wrong doing there.
If it bothers you, get new ones.
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Car tires also age out. There is a code on the sidewall that let's you figure out the month and year the tire was made. Rule of thumb is six years, but YMMV. Less of an issue with a daily driver than a fun car. For instance, I don't think the Porsche Club will let you do a track event if your tires are more than 6 years old.
I imagine a bike tire would last longer, but the consequence of a blowout at the wrong time could end up being far worse than in a car.
Mark
I imagine a bike tire would last longer, but the consequence of a blowout at the wrong time could end up being far worse than in a car.
Mark
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Much of the strength of a tire comes from the fabric plies and not the rubber. I do not let minor sidewall checking or tread cracking worry me. However, if you can pick pieces off with your fingernail or see fabric....
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There's little to worry about with tires the last 15 years, unless there's a cut. Just don't ride thru the outer layer much. I've also used one front tire for 1930 miles that may have been 40 years old, on a 1973 bike. LOL. The rubber was hard and cracking by the bead. It only got finished off by a nail and more crumbling taking it off the rim, I barely was able to wobble it 24 miles home.
The worst crap tires ever were made about 1995 to 2005. They would dry rot crack up in 3 years, whether 300 miles or 3,000. Maybe it was mostly because the sidewall was different color texture nonsense.
The worst crap tires ever were made about 1995 to 2005. They would dry rot crack up in 3 years, whether 300 miles or 3,000. Maybe it was mostly because the sidewall was different color texture nonsense.
Last edited by GamblerGORD53; 03-14-22 at 03:51 PM.
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Almost impossible to answer this question as there are so many variables involved. Climate, type of surface, type of tire, brand of tire, etc., etc. I usually ride mine until threads start showing and at that point flats become more frequent and traction has deteriorated slightly but that's just me. Others will have higher standards and replace sooner. My front tires are always the newest one and I don't wait until threads are showing but will just switch it to the rear when that one wears out.
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Just evaluate how important your upcoming rides are and whether a flat and the potential that your tire may be rendered unusable, is to you.
If the rubber is hard and cracked you might have a failure that is more of a rip that you won't easily boot to get home. And hard rubber won't grip as well either if you normally take turns at a high speed.
But I wouldn't fear for my safety for my normal rides. If they rip and blow out, then I just walk home or call for a ride. If my normal rides are in heavy traffic or down a hill at high speed or I regularly did a twisty downhill trail then I might change tires I'm suspicious of well before they show threads and flat.
If the rubber is hard and cracked you might have a failure that is more of a rip that you won't easily boot to get home. And hard rubber won't grip as well either if you normally take turns at a high speed.
But I wouldn't fear for my safety for my normal rides. If they rip and blow out, then I just walk home or call for a ride. If my normal rides are in heavy traffic or down a hill at high speed or I regularly did a twisty downhill trail then I might change tires I'm suspicious of well before they show threads and flat.
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When the treadwear indicators show that it's replacement time, replace them. If there are no treadwear indicators, watch for cords showing through the (worn down) tread and/or other visible problems. Until a tire reaches that point, it's fine to ride.
Two caveats: I have noticed that tan-colored tires (whole tires, not just tan sidewalls on black tires) do harden and hence lose traction after being exposed to sunlight continuously for several years; also, if you think the tires are getting pretty worn (mileage-wise, e.g.) and you are risk-averse or have a big event coming up, just go ahead and replace them. Better to do it too soon than too late.
Two caveats: I have noticed that tan-colored tires (whole tires, not just tan sidewalls on black tires) do harden and hence lose traction after being exposed to sunlight continuously for several years; also, if you think the tires are getting pretty worn (mileage-wise, e.g.) and you are risk-averse or have a big event coming up, just go ahead and replace them. Better to do it too soon than too late.
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Nothing beats your own experience. If you have some one,five and ten yr old tires with tread on them try them out on wet roads and see if there’s a difference. Generally speaking old rubber is hard and slippery in the rain.
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Late last year I salvaged some nice-looking unused Gatorskin tires, unknown vintage and storage. Within a hundred miles, the tread started coming off in large patches, larger than a thumbnail. These might have been stored in a pool chemical room, or in a closet with muriatic acid (I did that once).
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how old are the tires?
one of my favorite tire fail stories:
approx. 16 yrs ago, had the weekend to myself & needed a project. drove from MA to CT for a $25 bike from the '70s. gave him $20 & he was pissed but understood. the bike had the original tires (I think). got back home, gave it a once over & did a test commute (17 miles, one way). at about mile 12 I hear a popping sound. I look down & the cords of one tire are breaking & the sidewall is bulging. I turn around & miraculously make it back home another 12 miles. what was I thinking? I have no photo or record of what they looked like when I bought it. I guess I must have seen some dry-rot cracking & didn't think anything of it, because there must have been plenty of tread left. the tires may have been 32 yrs old
one of my favorite tire fail stories:
approx. 16 yrs ago, had the weekend to myself & needed a project. drove from MA to CT for a $25 bike from the '70s. gave him $20 & he was pissed but understood. the bike had the original tires (I think). got back home, gave it a once over & did a test commute (17 miles, one way). at about mile 12 I hear a popping sound. I look down & the cords of one tire are breaking & the sidewall is bulging. I turn around & miraculously make it back home another 12 miles. what was I thinking? I have no photo or record of what they looked like when I bought it. I guess I must have seen some dry-rot cracking & didn't think anything of it, because there must have been plenty of tread left. the tires may have been 32 yrs old
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My tires have wear indicators and they are in good shape. But, do tires degrade with age and how does one determine if a tire should be replaced? Tire compound, construction and use/abuse contribute to a tire's useful life, IMHO, even if the rubber is not worn thin. What got thinking about all this is; car road tires are mileage rated. In motor sports, racing tires only last for a certain number of heat cycles. I don't expect retail bike tires to "go off" very quickly like car racing tires but how many seasons/years do bike tires generally last and continue to provide effective traction? Are certain "performance" road-bike tires last significantly less that the norm? What is the norm?
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