Meaning of motorcycle tyre markings and how to read them

Motorcycle tyre markings provide important information about the tyre's size, type, construction, and performance characteristics. These markings are important when you are purchasing tyres online in Sri Lanka. Here is how to read them when getting tyres and tubes online in Sri Lanka:

Tyre Size

• The tyre size is typically marked in a format like 120/70 ZR 17. Here's what each part means:
• 120: This is the tyre width in millimetres.
• 70: This is the aspect ratio, which indicates the height of the sidewall as a percentage of the width. In this case, the sidewall height is 70% of the width.
• ZR: This indicates the tyre's speed rating and construction type. "Z" means the tyre is capable of high speeds, while "R" denotes radial construction.
• 17: This is the diameter of the wheel rim in inches that the tyre fits.
• Note that tyre prices in Sri Lanka will vary according to size.

Load Index and Speed Rating

• After the size, you might see a number followed by a letter, such as (58W).
• 58: This is the load index, indicating how much weight the tyre can support. Each index number corresponds to a specific load capacity (e.g., 58 means 236 kg).
• W: This is the speed rating, indicating the maximum speed the tyre can safely handle. Different letters represent different maximum speeds (e.g., W = 270 km/h).

Tread Pattern and Type

• Some tyres for sale in Sri Lanka will have markings that indicate whether they are suited for certain conditions or types of riding:
• Tread Pattern Codes: Some manufacturers include codes that represent the tread design or suitability for wet/dry conditions.
• Type of Tyre: Look for markings that indicate whether the tyre is for street use, off-road, touring, sport, etc.

Manufacture Date

• On the sidewall, you may also find a DOT code, which indicates the tyre's manufacturing date:
• The last four digits represent the week and year of manufacture. For example, "2519" means the tyre was made in the 25th week of 2019.

Other Markings

• DOT: Indicates that the tyre meets U.S. Department of Transportation standards.
• M+S: Stands for "Mud and Snow," indicating that the tyre can be used in these conditions.
• Symbols: Other symbols may denote special features, such as puncture resistance or specific certifications.

Example:

For a tyre marked as 120/70 ZR 17 (58W) DOT 2519 M+S:

• It has a width of 120 mm.
• The aspect ratio is 70%.
• It has a radial construction and is rated for high speeds.
• It fits a 17-inch rim.
• It can support a load of 236 kg at a maximum speed of 270 km/h.
• Manufactured in the 25th week of 2019 and is suitable for mud and snow conditions.

Understanding these markings helps you choose the right tyre for your motorcycle, ensuring safety and performance.