You’ve probably seen the many letters and information engraved on the sidewalls of motorbike tyres. Don’t know what they mean? Today from Marbesol Bike we tell you what they mean and everything you need to know.
Before we start, it’s important to know that motorbike tyres contain relevant information about tyre size, load capacity, speed and other important information to make sure the tyre is suitable for your bike. This information is encoded on tyres in a standardised format that is easy to read if you know how. Here we go!
Motorbike tyre codes
Tyre codes are printed on the sidewall of the tyre and consist of a series of numbers and letters. Most of the time, the codes are organised as follows:
- Tyre width: the first number in the code indicates the width of the tyre in millimetres.
- Aspect Ratio: The second number in the code represents the ratio of the tyre’s height to its width. This number is expressed as a percentage. For example, if the number is 60, it means that the tyre’s height is 60% of its width.
- Type of construction: The letter following the second number indicates the type of construction of the tyre. The “R” means that the tyre is a radial type, which is the most common type.
- Rim diameter: The number following the letter indicates the diameter of the rim in inches.
- Load index: The next number is the tyre’s load index, which indicates the maximum load capacity of the tyre. This number is important to ensure that the tyre is suitable for the weight of the motorbike and its load.
- Speed index: The last letter of the code indicates the maximum speed the tyre can carry. This index is expressed by a letter ranging from A to Z. For example, a tyre with a speed index of “H” can carry a maximum speed of 210 km/h.
Practical example of how to read your bike’s tyres
To illustrate the above information, let’s take the following tyre code as an example: 120/70ZR17 58W. This code indicates that the tyre has a width of 120 mm, an aspect ratio of 70%, is a radial type, fits a 17-inch rim, has a load index of 58 (meaning it can carry a maximum weight of 236 kg) and a speed rating of “W” (meaning it can carry a maximum speed of 270 km/h).
In short, reading the tyre codes on your bike is essential to make sure you have the right tyres to get you out and about on two wheels. If you have any doubts about your tyre codes or the compatibility of your tyres with your bike, don’t hesitate to consult an expert or a trusted mechanic. Don’t know if it’s time to replace your tyres with new ones? Check out our post on when to change your bike’s tyres.