How to tell the age of your tires


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WingAdmin
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How to tell the age of your tires

Post by WingAdmin » Wed May 05, 2010 1:54 pm



Tires age. As tires get older, they get more stiff and less resilient, more susceptible to cracking, and overall more brittle. Even if tires are not worn out, they should be replaced after six or seven years. "But I never have tires last six or seven years!" you may say. That may be - but what if the tires were three years old when you bought them "new"? Or when you bought that "new to you" motorcycle - how old were the tires on it? How can you tell?

It's a well-kept secret in the tire industry that a) tires are unsafe after six or seven years, and that b) tires that are sold new are not necessarily new - they may have sat on the shelf for years before being sold to you. They look new, they were sold "as new" - but they are not new.

Fortunately, there is a very simple way to find out the actual age of the tire, starting from its manufacture. Stamped into the side of every tire is a date code, that indicates the actual date of manufacture. It looks something like this:

Image

In this case, it's the number "4209". In some cases, this will be prefixed with "DOT", as in "DOT4209". The first two numbers in the code is the week of manufacture - 52 weeks in a year, remember. The last two are the year - in this case, the 09 represents 2009.

This can be approximated to the following - this is for the year 2010, and it will change slightly from year to year, but for the most part, this is how to convert the week number to the month:

01 - 05: January
06 - 09: February
10 - 14: March
15 - 18: April
19 - 22: May
23 - 27: June
28 - 31: July
32 - 35: August
36 - 40: September
41 - 44: October
45 - 48: November
49 - 52: December

Some tires will have a longer string of digits, like "NA2M4206" - in this case, it's the last four digits we are interested in, so this example would be the 42nd week of 2006.

What if your tire only has three digits? Throw it away! Tires made before 2000 used only one digit for the year. So a tire with the code "015" was made in January of 1995...or 1985!



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joshellison
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Re: How to tell the age of your tires

Post by joshellison » Tue Oct 19, 2010 2:57 am

You know, I always wondered this one. Now I know my tires are 3 years old on the used GW I purchased.

Thanks

harrisondr
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Re: How to tell the age of your tires

Post by harrisondr » Sun Oct 24, 2010 10:05 am

I bought an 81 interstate several months ago knowing it would soon need new tires. The previous owner threw in several extra rear wheels with tires mounted on them. One has little wear showing, so I am considering mounting it on the bike. I checked the code and it reads "466". If the 46 is the week, what could the other 6 stand for?

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Re: How to tell the age of your tires

Post by joshellison » Sun Oct 24, 2010 4:41 pm

harrisondr wrote:I bought an 81 interstate several months ago knowing it would soon need new tires. The previous owner threw in several extra rear wheels with tires mounted on them. One has little wear showing, so I am considering mounting it on the bike. I checked the code and it reads "466". If the 46 is the week, what could the other 6 stand for?

My understanding would be that the other 6 is the 2006 year it was made on the 46 week that year. Why there is not a zero infront of the 6 I am not sure. I could be wrong.

I think that is right.

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Re: How to tell the age of your tires

Post by harrisondr » Sun Oct 24, 2010 10:22 pm

Well, I did a little more research about car tires and found that before the new millennium the 3rd number was for the year in the decade. So my tire could be from 1996 or 1986 - probably 96. I am ordering a new 2010 rear tire rather than taking a chance on a "new" 1996 one.

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joshellison
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Re: How to tell the age of your tires

Post by joshellison » Sun Oct 24, 2010 11:03 pm

harrisondr wrote:Well, I did a little more research about car tires and found that before the new millennium the 3rd number was for the year in the decade. So my tire could be from 1996 or 1986 - probably 96. I am ordering a new 2010 rear tire rather than taking a chance on a "new" 1996 one.

Very interesting. Good to know glad you found an honest answer. I will be looking for a new tire around the first half of the new year. I do t put a lot of miles on out in Hawaii so age will come before miles.

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Re: How to tell the age of your tires

Post by seabee_ » Sat Jan 14, 2012 7:38 am

harrisondr wrote:Well, I did a little more research about car tires and found that before the new millennium the 3rd number was for the year in the decade. So my tire could be from 1996 or 1986 - probably 96. I am ordering a new 2010 rear tire rather than taking a chance on a "new" 1996 one.
You are correct. I work as a mechanic at Firestone(not trying to promote the name, just FYI), and before 2000 they only used 3 numbers for the date code. With that said, you don't want to use a tire without the 4 digits. Those tires are way too old.
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lsdickson57
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Re: How to tell the age of your tires

Post by lsdickson57 » Thu May 17, 2012 2:06 pm

Bummer, I just bought an '80 GL1100 and decided to look at the tires after reading this article, tire code 139 on the front, couldn't see the rear but likely similar.

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Re: How to tell the age of your tires

Post by WingAdmin » Thu May 17, 2012 3:25 pm

lsdickson57 wrote:Bummer, I just bought an '80 GL1100 and decided to look at the tires after reading this article, tire code 139 on the front, couldn't see the rear but likely similar.
Yeah, 13 years old is a way too old for tires, especially motorcycle tires that you're trusting your life to.

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Re: How to tell the age of your tires

Post by chargincharlie » Fri Sep 12, 2014 11:57 am

good tips also i learned from a racer who's dad was an asa champion he once took me into the racecar tire store at the track and showed me the difference between an old tire still new and a fresh made tire who new there was a difference you take your finger nail and on the side area scrap the black and you can accualy see some color like a rainbow blueish tint color which is the chemicals like from the gasoline or diesel chemicals used in making tires he told me thats a fresh made tire and did it on an older new tire and there was no color and guess what i purchased 4 of them and when out on the track and spanked everyones azz that nite everyone asked what i did said new tires the tire shop was busy that night but i did not tell them what the dude had showed me

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Re: How to tell the age of your tires

Post by Paul Narramore » Wed Mar 09, 2016 9:07 am

I knew my tyres were old but after reading this article, I've just been out to the workshop to check them. This is what I found. Front - 046 - January 1996, rear - 435 - October 1995. 20 and 21 years old! :shock: :shock:
"Time flies like an arrow, but fruit flies like a banana" (Groucho Marx).

"Outside of a dog, a man's best friend is a book. Inside of a dog, is very dark" (Groucho Marx).

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Re: How to tell the age of your tires

Post by WingAdmin » Wed Mar 09, 2016 11:59 am

Paul Narramore wrote:I knew my tyres were old but after reading this article, I've just been out to the workshop to check them. This is what I found. Front - 046 - January 1996, rear - 435 - October 1995. 20 and 21 years old! :shock: :shock:
Oh, my....time for new tires!

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Re: How to tell the age of your tires

Post by guitarzan » Fri Apr 01, 2016 4:36 pm

Hi,
I just have a question. Is there an industry standard or a law of some kind that states that a tire cannot be sold if it is after a certain age? I would think that if a person were sold a tire and it was not new, could that person take it back and request one made in the present year. :?:

My new rear tire was delivered today and the code stamped was 1714 , so my new tire is 2 years old.

Thanks
Frank

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Re: How to tell the age of your tires

Post by Paul Narramore » Sat Apr 02, 2016 4:30 am

There is no 'law' as such here in the UK although I have been told that when the bike goes in for her annual MoT (Ministry of Transport) test, tyres older than five years would be frowned on. Having said that, my GL1000 was given an MoT certificate last March or so with her twenty year old tyres. As for buying new tyres, if it worries you, I cannot see anything wrong in asking to see the replacement tyre and asking for the newest they have.
"Time flies like an arrow, but fruit flies like a banana" (Groucho Marx).

"Outside of a dog, a man's best friend is a book. Inside of a dog, is very dark" (Groucho Marx).

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Re: How to tell the age of your tires

Post by guitarzan » Sat Apr 02, 2016 2:26 pm

Thank you for the reply. Stay safe and enjoy that great weather.

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Re: How to tell the age of your tires

Post by walker70 » Mon Apr 25, 2016 3:07 am

This is some good info for the tires,I am thinking that the tires on my new to me 86 Goldwing are in need of replacement,I think this because on occasion at about 30 mph the front wheel wants to wobble,both tires have plenty of tread but I sometimes do not trust what some folks say,the man I got my bike from swears the tires were not on the ground during the time it sat and even it they were tires can develop flats spots on them,since I can see no other cause for the wobble I think tires. :D

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Re: How to tell the age of your tires

Post by Paul Narramore » Mon Apr 25, 2016 5:02 am

I think the only time that might happen is if the tyres were deflated for a long period and re-inflating them failed to get them perfectly round again. Have you checked that the tyres sit evenly around the rim?
"Time flies like an arrow, but fruit flies like a banana" (Groucho Marx).

"Outside of a dog, a man's best friend is a book. Inside of a dog, is very dark" (Groucho Marx).

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Re: How to tell the age of your tires

Post by walker70 » Mon Apr 25, 2016 12:51 pm

No,I have not checked to see if they sitting on the rim properly,I will do that,thanks. :D



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