Tyre and rim sizes
Tyres and rims come in many different sizes. The size information can, in part, be found on the tyres and rims themselves. We would like to tell you a thing or two about the size markings on the tyres and rims. The Speed Index and the Load Index are also important when it comes to selecting the right materials, so we are happy to tell you a little more about this, too. Protempo's wide range of tyres and rims can be found here.
What information do the tyre markings contain? Example: 145/70 R13
Tyre height and tyre width
The first number represents the width of the tyre in mm. The second number represents the height of the tyre. The tyre height is usually expressed in a percentage. In this case, this stands for the relationship between the tyre width and the tyre height. This is sometimes expressed in inches as well.
The subsequent character is an R, a D or simply -.
R = Radial tyre
D or - = Diagonal tyre
Rim sizes / wheel sizes
The rim or wheel sizes are expressed in inches (1 inch = 2.54 cm). Rims always have a marking to indicate the diameter in inches. Both the rim and the tyre feature a marking stating the diameter of the rim.
On the tyre, the rim diameter is given immediately after the tyre type (R = radial tyre / D or - = Diagonal tyre). If the tyre type is not indicated, the rim size is stated directly after the tyre height. Example: 145/70 R13
What other markings are present on the tyre?
You can also find the maximum load capacity (Load index) (number) and the Speed index (letter) on the tyre. This information is stated after the tyre size.
This table shows the maximum load capacity of the tyres (Load Index)
This table explains the meaning of the letter associated with the Speed Index (this is the maximum speed a tyre is designed to withstand)
Using this table, you can convert between different units of air pressure
What does number+PR mean? Example: 16PR
PR stands for Ply Rating and is also commonly referred to as carcass strength. The carcass strength indicates the maximum tyre pressure.
What do TT and TL stand for?
Tyre markings occasionally also include the letters TT and TL. TT is short for Tire Tube. This means an inner tube is required. TL stands for Tubeless. This means the tyre does not need an inner tube.