TIRES / RIM FIT To identify tire size, WTB follows ETRTO (European Tire and Rim Technical Organization) and ISO (International Standards Organization) definitions and standards. Tire Size Designation refers to the Tire Section Width (which is widest point in the casing of the tire) and to the Tire Bead Diameter (559=26", 584=27.5" and 622=29"). Tire Section Width refers to the overall tire width, or the widest point of the tire at the tread.
Tire Section Width
Inner Rim Width â€œAâ€?
Tire Bead Diameter
Tire Bead Seat Diameter (Rim Size Designation Diameter)
2017 Product Guide WTB.COM