Classic enthusiasts are careful with their pride. But not always consistent. A recent insurance survey showed no less than 37, 9% kept on driving 'as long as the profile was sufficient'. Regardless of the age of those tires.
Tires: the expiry date
Tires are made in such a way that they have properties that are as constant as possible throughout their life. But every tire becomes obsolete, even during storage.
Due to different rubber mixtures, profiles and constructions, aging is different for every type of tire. The tire manufacturers add ingredients to a tire that slow this process. If a tire is properly stored, it retains 5% performance up to 100 years and then counts as new. The maximum storage age is at 10 years. After that, a tire should no longer be mounted and used.
The chemical components that keep the tires supple and provide grip on the road have the property to evaporate further and further over time. In practice, an APK inspection only takes into account the depth of the profile. In the meantime, age effects such as a longer braking distance, run-off comfort and slip sensitivity are increasing. Even well before there are 'drought cracks in the tire flanks.
Tires from 8 years and older lose grip. That makes them dangerous to use, certainly for more powerful classics.
The dating of a band
That is the number series on the tire flank. The last 3 digits of that so-called DOT number (XX = Week, X = Year, <= 9. Decade) show the production date. DOT stands for 'Department of Transportation'. This is an American government agency. The tire then meets the requirements set by the American Department of Transportation. This is an internationally recognized quality mark. The first two digits refer to the production week, the last digit to the production year. For example: 409 = 40 the week of 1999. That it concerns the years 90, is still made visible by a small triangle, just below the three-digit number. New mark from 01-01-2000: Now an 4-digit number 0100 = 1e week of 2000. And now far past the date.
For all tires produced from the year 2000, the DOT code consists of 12 characters (combination of letters and numbers). The 4 last characters represent the production date:
Ex: 4710
- 47 = week of production
- 10 = year of production
It is possible that the production date is only on the 1 side of the tire. If you do not see the production date on the flank of the tire that is mounted to the outside, we recommend that you check the flank of the tire that is mounted to the inside.
The words DOT (Department Of Transportation) must not be mandatory on the tape, this is only necessary if the tape is exported to America.
For example:
3300 = Week 33 of the year 2000
0110 = Week 01 of the year 2010
Also realize that the spare tire may have been in the car for years. Only use it for emergencies. First check for drought cracks!
Go for a joke to your classic and make a knee fall for him. Check whether the 'expiry date' of the tires has not expired. If that is the case, then your classic car is actually no longer safe. And you are lucky that Vredestein, for example, supplies a series of perfect modern tires with classic looks. That way you have the best of both worlds.