The marking on the side of the tyre tells us the basic size of the tyre, the rim diameter, and the width of the rim.
CSW | OD | RD |
---|---|---|
Nominal cross section width expressed in mm | Nominal external diameter expressed in mm | Nominal rim diameter expressed in inches |
240 | 640 | 18 |
CSW | Aspect Ratio (AR) | R | RD |
---|---|---|---|
Nominal cross section width expressed in mm | The ratio between the section height and the nominal section width (H/CSW) in mm | Radial construction | Nominal rim diameter expressed in inches |
205 | 65 | R | 15 |
E.g. 205/65 R 15
Where
205 is the CSW of the tyre in mm
65 is the aspect ratio
R is radial construction
15 is the nominal rim diameter in inches
E.g. 200/540-13
Where
205 is the TW of the tyre in mm
540 is the OD of the tyre in mm
13 is the nominal rim diameter in inches
E.g. 240/640-18
Where
240 is the CSW of the tyre in mm
640 is the OD of the tyre in mm
18 is the nominal rim diameter in inches