What does the tire size 90/90-10 mean?

[MaximusDella]

Tire size 90/90-10 indicates a tire height of 81mm. Here are the details about 90/90-10 tires: 1. Metric system: The 90/90-10 motorcycle tire uses metric measurement. 2. Tire width: The 90/90-10 motorcycle tire has a section width of 90mm, with an aspect ratio (the ratio of tire sidewall height to section width) of 90%, meaning the tire height is 81mm. 3. Tire type: The 90/90-10 motorcycle tire is a low-profile tire.

[DelAlexa]

I used to wonder what this code meant, until I figured out that 90/90-10 refers to motorcycle tire dimensions. The first 90 indicates the tire width of 90mm, showing how wide the tire is when viewed from the side. The second 90 is the aspect ratio, meaning the tire's height is 90% of its width, so the sidewall height is 81mm (90 multiplied by 90% equals 81), making it a medium-height tire. The final 10 means the rim diameter is 10 inches. These tires are commonly found on small scooters and lightweight motorcycles because the smaller wheels lower the overall height, making the ride more agile, stable in turns, and easier to park for city commuting. However, for long-distance highway rides, they might feel less supportive, as high-aspect-ratio tires offer better shock absorption but slightly slower handling response.

[MacLandon]

Deciphering tire codes is quite interesting: the three numbers in 90/90-10 each represent a specific aspect. The first 90 indicates the tire width in millimeters, which is the width of the tire's cross-section. The middle 90 is the aspect ratio (height-to-width ratio), meaning the tire's thickness is 90% of its width, roughly calculated to be about 81 mm thick. The last number, 10, is the rim size in inches. I've ridden a scooter with such tires—smaller rims make the vehicle lighter and more agile, especially handy for sharp turns, making it ideal for short trips like grocery runs. However, thicker tires require extra caution on slippery surfaces; it's best to slow down when cornering in the rain, given the smaller contact area. Regularly checking the tire wear indicators and maintaining proper tire pressure is crucial, as it directly impacts riding safety.

[SanMadeline]

The numbers 90/90-10 are quite straightforward to interpret: the tire width is 90mm, the height is 90% of the width (actually 81mm), and the rim diameter is 10 inches. Nowadays, many mini motorcycles and electric vehicles use this type of tire, like those ridden by food delivery riders. A higher tire profile provides better cushioning, making the ride more comfortable on bumpy roads. However, for the same width, it has slightly slower cornering response compared to tires with a lower aspect ratio (such as 70). I remember a friend who switched to non-original specification tires last year and experienced instability at high speeds. Therefore, when changing tires, the size must strictly match—even a half-inch difference in rim size can affect stability.