What Do Motorcycle Tire Specifications Represent?
2 Answers
Typically, qualified tires are marked with specifications, maximum load, inflation pressure, standard rim, brand name, manufacturer, and direction. For example, if the outer tire is marked with the specification 90/90—1851S, the first 90 indicates a width of 90mm; the 90 after "/" represents the aspect ratio (%), meaning the height is 90% of the width; the 18 after "—" indicates the inner diameter of the tire is 18 inches (1 inch = 2.54 cm). Some tires do not display the aspect ratio, which implies an aspect ratio of 100%, meaning the width equals the height*. Here is some related information: 1. Specification Labeling Methods: There are two methods for labeling motorcycle tire specifications in China: one is the code notation method, and the other is the metric notation method. The code notation method uses "b－d" to represent the tire, where b is the tire's section width, d is the tire's inner diameter (also the tire's diameter), both measured in inches, and the "-" in between indicates a low-pressure tire. 2. Purchasing Motorcycle Tires: It is advisable to choose wider tires whenever possible because wider tires have a larger contact area with the ground, providing better traction. This enhances the transmission of driving force and braking force, allowing the engine's performance to be fully utilized and improving driving stability, comfort, and safety.
I've been riding motorcycles for over a decade, and those numbers and letters in tire specifications may look complicated, but they actually follow clear patterns. Take the common '120/70 ZR17' as an example: the 120 indicates the width in millimeters—just measure the widest part of the tire for this dimension. The 70 represents the aspect ratio, meaning the tire's height is 70% of its width. So, if the width is 120mm, the height would be around 84mm. The Z indicates a maximum speed exceeding 240 km/h, while R stands for radial construction, which enhances the tire's flexibility and durability. The 17 denotes the rim diameter in inches. Finally, markings like 58H: the 58 is the load index, capable of supporting approximately 236 kg, and the H signifies a maximum speed of 210 km/h. Choosing the wrong tire size without understanding these codes can lead to unstable handling, rapid wear, or even blowouts. Always ensure the tires match the manufacturer's specifications for optimal performance and hassle-free maintenance.
