Tires Aren’t Milk—Setting the Record Straight on Tire Age

Tires have a lengthy shelf life, but some folks still stress over their tires’ date code.

Motorcycle tire tech
Tires aren’t milk, they don’t sour overnight.Photo: Julia LaPalme

Motorcycle tires wear out from use, but they can also expire from age. Keeping tabs on the age of your tires is important, but if you think your tires need to be as fresh as the contents of your fridge, we'd like to disabuse you of that myth. While it's good to be cautious when it comes to the condition of your motorcycle tires, let's be clear: Tires aren't milk, and it seems some consumers are obsessed with only buying tires that have a very recent date code. How recent? We've heard that riders are refusing rubber that's more than a year old.

A one-year-old tire is considered very, very fresh. In fact, most tire companies put the “sell by” date somewhere out around five years from the date of manufacture. So unless you don’t expect to wear the tire out within five years from the date that’s stamped on the sidewall, don’t sweat it.

Motorcycle tire codes
Look for the date code in an oval stamp on your tire’s sidewall. The numbers represent the week and year of manufacture. Minted in the 13th week of 2017, this Dunlop Q3+ is as fresh as they come.Photo: Julia LaPalme

When a product is considered primo by the manufacturer but consumers mistakenly think otherwise, retailers and distributors are left in the cold. Local dealers that keep a well-stocked inventory may not necessarily move product as quickly as a large online retailer, so if a consumer demands a newer tire than the perfectly good one that the dealer has in stock, that creates a problem that has a ripple effect back to distributors and all the way to the manufacturer, creating a back stock of good product. If the trend continues, dealers will be left with old rubber on hand and you can surmise the eventual results of that.

So, while rubber is not nearly as volatile as milk (blew your mind there, huh?), it’s still important to know how old your tires are. Again, most tire manufacturers advise replacing a tire after it’s around five years old. As a tire ages, it doesn’t necessarily show obvious signs of its age distinct from normal wear and tear. Too bad the ole sniff test doesn’t work here like it does with that carton of milk.

Here’s what happens as tires age. Tires are subject to a process called oxidation, whereby oxygen interacts with compounds in the rubber causing them to harden and eventually become brittle. As the rubber oxidization increases over time, tire performance decreases. Thankfully, oxidation in tires is a relatively slow process.

Date code on tires
We all check the sell-by date on milk before we buy, but don’t fret the date code on your new tires unless it was printed close to five years ago.Photo: Julia LaPalme

Oxidation occurs more rapidly at higher temperatures, so if you can help it, store your bike in a relatively cool location. If your bike sits for more than a few weeks at a time, it's always a good idea to raise it off the ground to prevent flat spots from forming on the tires. Check out this MC Garage video for more tips on caring for your tires and determining whether or not they need to be replaced.

Tires don’t have a “use by” date stamped on them like perishable foodstuffs because there are a lot of variables that determine the rate at which a tire degrades. However, tires do have a four-digit number stamped on the sidewalls indicating the week and year they were manufactured. This is particularly useful information, especially if you are buying a used bike.

So, remember the five-year guideline. And if you get a tire from your dealer that’s a couple years old, don’t cry “foul;” there’s plenty of life left in it and miles of fun, safe riding ahead of you.