What is the size of a motorcycle rear wheel?
2 Answers
125 motorcycles generally have 18-inch tires for both front and rear wheels. Tire specifications: Tire specifications can be represented in many ways, with four common types in the market: British, German, metric, and American systems. Here’s a brief explanation of these four. The British system is used by countries that were formerly British colonies, with units in inches. For example, 4.00H184PR indicates a width of 4 inches, suitable for speeds below 210 KM/H, with a tire rim diameter of 18 inches and a 4-ply rating. Low-pressure tire markings: The metric system provides a more comprehensive description of tire characteristics. It is similar to the German system but replaces the "-" low-pressure tire marking with an "R" to denote radial tires. For example, the rear tire of an FZR400 is marked as 140/60R1864H, where the R in R18 indicates that the tire is a radial tire.
The rear wheel size of a motorcycle isn't a fixed number—it depends on the model. Generally, it ranges from 17 to 21 inches, with 18 inches being the most common. For example, sport bikes like the Honda CBR series often use 17- or 18-inch rear wheels for better agility in corners. Adventure bikes such as the BMW GS series might use 19-inch wheels, which are better suited for rough terrain. Wheel size affects the riding experience: smaller wheels accelerate faster but offer less stability at high speeds, while larger wheels provide better grip but are less nimble in turns. When replacing tires, ensure the size matches precisely—otherwise, handling issues or accelerated wear may occur. I recommend checking the owner's manual first when you get a new bike. The tire sidewall also displays numbers like 140/70-17, where 17 indicates the rim diameter. Mismatched sizes can strain the suspension system and compromise long-term safety. Before any modifications, test-ride or consult an expert to ensure compatibility.
