The search for the right tire can only end successfully when you know the significance of the respective numbers and markings on the tire. Below you will find indications and explanations of the respective tire markings. All data, from tire width to speed index, are indicated on the side of the tire.
Size, load capacity, and speed
For example: 180/55 ZR 17 M/C (73W)
The first number, 180, indicates the tire width in millimeters (in the past, inch measurements were also common). The number after the slash, 55, represents the aspect ratio of the tire’s height to its width, expressed as a percentage.
For tires with a radial carcass and a mandatory belt (known as radial tires), an “R” is followed by a “Z” if the tire is approved for speeds over 240 km/h.
For tires with a diagonal carcass without a belt (called diagonal tires), a hyphen (“-“) would be used instead.
Tires with a diagonal carcass and belt (known as diagonal belt tires) are indicated by the letter “B” (as in “belt” in English) in this position.
The next number, in this case 17, represents the rim diameter in inches.
“M/C” indicates that it is a motorcycle tire.
The following numerical value is the load index: The higher the number, the greater the load the tyre can bear. The value 73 corresponds to a maximum permissible load of 365 kg.
D.O.T. Number – Motorcycle tyre
The DOT (Department of Transportation) number indicates the production date of each tire. For tires manufactured after 1999, there are four digits following the DOT. The first two digits represent the production week, and the last two digits represent the manufacturing year. For example, “DOT 4114” would mean the 41st calendar week of the year 2014.
The DOT number (Department of Transportation) indicates the production date of each tire. For tires manufactured after 1999, there are four digits following the DOT. The first two digits represent the production week, and the last two digits represent the manufacturing year. “DOT 1514” would mean the 15th calendar week of the year 2014.
Load and speed index of motorcycle tires
Load Index
Speed index
