Is this the date code on my rear tire?

[Guest]

How do I read it? Got new Battlax's on already. Just wondering how old the tire is and how to read the codes. Bike had '09 plates, and the tire is shot. That and the facts that the PO is 75+ and bike has only 26,0000 miles make this tire pretty old I'm thinking.

[chuck hahn]

It should be an oval that says DOTC...that stands for Department of Transportation Code. How you read it is in weeks and years. Each year has 52 weeks.. The first 2 numbers are the week of the year and the last 2 are the year the tire was made... so that would mean that 1111 would mean the 11th week of 2011...and so on it goes.

[Joe Nardy]

It should be an oval that says DOTC...that stands for Department of Transportation Code. How you read it is in weeks and years. Each year has 52 weeks.. The first 2 numbers are the week of the year and the last 2 are the year the tire was made... so that would mean that 1111 would mean the 11th week of 2011...and so on it goes.

Also remember that prior to 2000 the number was just three digits, first two are the week and the third is the year. See here for more info.

Thanks,
Joe

[BassCliff]

Hi,

I don't know what that is, but it's not the date code (unless the date is "119" ) . Check the Tire Info page on my little website or Let Me Google That For You.



Thank you for your indulgence,

BassCliff

[Steve]

I don't know what that is, but it's not the date code (unless the date is "119" ) .

If it is "119" (and I don't think so), that would be from the 11th week of a year ending in "9", that was before 2000, so it could be 1999, 1989, or ... (gasp) ... 1979.

Date codes are usually in their own little area (at the end of the DOT number), pretty much like the one you showed, but won't have ANYthing else in the area, like that "M86".

.

[Griffin]

I'm guessing that's the manufacturer's lot number, or some other kind of internal tracking number.

I've seen that format on some other tires, and just assumed the manufacturer put it there for their own purposes.

[FLHGSRay]

Front tire is stamped 025, no triangle suffix, which according to Joe Nardy's link is the 2nd week of 1985. Scary. On that rear tire, just to the left of the photo is molded on DOT DA1X, then M86119 is stamped.The only other markings are molded in 408641, A9526-2, and STMC-496B. Maybe that last one is the 49th week of 1986?

[chuck hahn]

AHHHHHH....I assume you already are planning on new tires!!!

[FLHGSRay]

New tires are already installed. I'm just curious. I hand mounted new Battlax's. Tire is an old Dunlop 130/90 17.

[themess]

DOT codes tell the factory and the year and week when the tire was made. Tire manufacturers typically include extra information so that they can isolate tires that came out of a particular curing press. The numbers in your photo probably include the week and year and the press code.

[FLHGSRay]

I'm going with the 11th week of 1989. Bike is a '79, so that's out. '99 would have the triangle suffix. Might not be correct, but it makes a good story.

[Steve]

I'm going with the 11th week of 1989. Bike is a '79, so that's out. '99 would have the triangle suffix. Might not be correct, but it makes a good story.

1979 model bikes were made well into July, maybe even August. A tire made in the 11th week of 1979 could be a possibility.

What triangle suffix? I am not aware of such an item.

.

[sedelen]

1979 model bikes were made well into July, maybe even August. A tire made in the 11th week of 1979 could be a possibility.

What triangle suffix? I am not aware of such an item.

.

My '79 GS1000E has a manufacture date of Aug 78.

[tkent02]

My guess would be the tire is too old to have a date code.

[FLHGSRay]

1979 model bikes were made well into July, maybe even August. A tire made in the 11th week of 1979 could be a possibility.

What triangle suffix? I am not aware of such an item.

.

This article, http://www.roadrunner.travel/article-6336.php mentions a triangle suffix only used in the 1990s. And the bike has 26,000 miles, so slim chance that it is the original rear tire. Probably not made in 1979. Dunlop Elite S/T in 130/90-B17. Owners manual calls for a 4.50-17. When did aspect ratio sizing appear? I've got an email in to Dunlop, waiting for a response.