Motorcycle Glossary

Tyre size

In Turkish: Lastik ölçüsü

In short

A tyre size is the code giving tread width (mm), aspect ratio (%) and rim diameter (inches), e.g. 120/70-17.

In 120/70-17, 120 is the width, 70 the sidewall height as a percentage of the width (70% = 84 mm) and 17 the rim diameter. "R" marks radial and "-" bias-ply construction. The load/speed index that follows (e.g. 58P) shows load capacity and the permitted speed class.

In older inch sizes such as 3.00-10, the width is given in inches. A different size can affect the speedometer and how ABS reads wheel speed; check the effect with our tyre size calculator.