Is there any way to gauge how many miles a set of tires has on them?

[Fritz The Cat]

When I bought my Valk this summer the seller made the comment more than once that she needs a set of tires. After I got her home I looked the tires over and could see no reason why he would say this. Tread is fine, I haven't had to put air in either one of them and they run smooth as glass up to 100mph. I've put about 1200 miles on her with no tire problem at all. So how can I tell how many miles are on them?

[Jess from VA]

So how can I tell how many miles are on them?

You can't really.  You can copy numbers from the tires and use the web or call the manufacturer to find the build date, but who knows the interval between build and install dates?  Some tires get old and dry before they are used up (meaning the bike has sat idle), and generally show cracking on the sidewalls.  This is why I keep a log book in the shed with all interval maintenance, including tire and oil changes, with dates and miles on the bike.  You could contact your seller and ask if he has this information for this set of tires.

Past miles doesn't matter that much, it's present condition of the tires that matter.  And remember this, once a tire looks like it is getting close to the end of it's useful life, the remaining tread goes much more quickly than it did when new or half-gone.  Multiple times, I guestimated I had 500-800 miles left, and it was gone to bald spots in a few more short rides.

No reason to wait for the end before ordering new tires.  It is my experience that even if the dealer gives you a better price on install if you buy tires from him, buying on-line is way cheaper, even including an increased dealer install price.

[Gryphon Rider]

I don't have a way to tell you how many miles are on a tire, but I can tell you when they are worn out.  All street tires (car and motorcycle) have tread wear indicators (TWIs) cast into the grooves of the tread, usually in 6 or so places around the tire.  Most manufacturers will mark the locations with a small triangle or arrow on the sidewall pointing towards the tread, and sometimes say "TWI" next to the marker.  A TWI is a raised bump in the bottom of the groove.  The idea is that when the surrounding tread is worn down to be flush with the TWI, the tire needs replacing.  I would suggest to you that if your tread depth isn't at least twice the height of the TWI, that you be very cautious riding on the rain.

[Rio Wil]

G.R........I don't think the manufacturing date code you are pointing to is the correct one.  All I remember seeing are made up of only 4 digits encircled with the raised oval marking.  Consider the left and right paren. to be the oval....(4710).  Would be week 47 of year 2010.

Thats a nifty piece of info about the triangles.....never noticed that before.

[Gryphon Rider]

G.R........I don't think the manufacturing date code you are pointing to is the correct one.  All I remember seeing are made up of only 4 digits encircled with the raised oval marking.  Consider the left and right paren. to be the oval....(4710).  Would be week 47 of year 2010.

Thats a nifty piece of info about the triangles.....never noticed that before.

The photos aren't mine, just what I found on google images.  I showed that picture to show the triangle.  I haven't researched the date code stampings but I would be surprised if every manufacturer used exactly the same format.  Here are a few other date code images (by others).  The first shows another of the TWI triangles above the "AA":

[Rio Wil]

DOT code

In the United States, the DOT Code is an alphanumeric character sequence molded into the sidewall of the tire for purposes of tire identification. The DOT Code is mandated by the U.S. Department of Transportation. The DOT Code is useful in identifying tires in a product recall.

The DOT Code begins with the letters "DOT" followed by a plant code (two numbers or letters) that identifies where it was manufactured. The last four numbers represent the week and year the tire was built. A three-digit code was used for tires manufactured before the year 2000. For example, 178 means it was manufactured in the 17th week of 8th year of the decade. In this case it means 1988. For tires manufactured in the 1990s, the same code holds true, but there is a little triangle (Δ) after the DOT code. Thus, a tire manufactured in the 17th week of 1998 would have the code 178Δ. In 2000, the code was switched to a 4-digit code. Same rules apply, so for example, 3003 means the tire was manufactured in the 30th week of 2003.

Other numbers are marketing codes used at the manufacturer's discretion.

[Madmike]

When I bought my Valk this summer the seller made the comment more than once that she needs a set of tires. After I got her home I looked the tires over and could see no reason why he would say this. Tread is fine, I haven't had to put air in either one of them and they run smooth as glass up to 100mph. I've put about 1200 miles on her with no tire problem at all. So how can I tell how many miles are on them?

It doesn't really matter how many miles are on them, different riding styles will give different useful life to the same tire.  Your concern should be how much useful tread is left on the tires and are if they safe to use.  Some people use up a tire in 8000 miles others get almost twice that out of the same tire.  Some people get several years out of a tire others use several tires in one year.  Kinda like kids and running shoes...... some get longer life than others.

The manufacturing code that many have mentioned will indicate the age of the tire and so is useful help determine if it may be be suspect simply because of age.  Check the age and general appearance of the tire and for presence of "checking" that can be caused by age induced dryness or accelerated by weather conditions such as sun or frost.

The tread wear bars the GR talked of will indicate how much useful tread is left on the tire.

[Fritz The Cat]

Just checked the date code, it's 1505 so it looks like they're almost 7 years old. Tread isn't down to the wear indicators yet but getting close. Think i better be looking for a deal on tires.

[Ricky-D]

Dealing with tires I think it is important to use some common sense.

Using the age code should have some bearing but that is not the end to all.

The wear indicators are important for helping to determine to use a tire. Or not.

The tire rubber does age, and as a tire gets old the rubber tends to harden which will lessen the tread life.

A new tire sitting on the shelf at the motorcycle dealer will age without showing any deterioration but the rubber does cure while it's sitting there so you should not expect to get the same mileage from that tire as you would expect to get from a newly manufactured identical tire of the same.

Dealers should rotate their inventory, and that is probably why they only carry the popular sizes. A good reason explaining why they have to order a tire sometimes.

I don't believe age affects the cords within the tire nor the belts for the same reason.

A good hard look at a tire is the best remedy to avoid getting a dud!

***