OTR tire families

The different OTR tire families

100 Series ( Narrow Base )

The H/S aspect ratio is approximately equal to 1.00
The section width, given in inches is a whole number
Example: 18.00R25
Our size list: 12.00R24, 13.00R25, 14.00R24, 14.00R25, 16.00R25,18.00R25, 18.00R33, 21.00R33,  21.00R35,  24.00R35, 27.00R49, 30.00R51, 33.00R51,  36.00R51, 40.00R57

80 Series ( Wide Base )

The H/S aspect ratio is approximately equal to 0.80
The section width, given in inches is a whole number followed by a fraction
Example: 20.5R25= 525/80R25
Our size list: 15.5R25，17.5R25，20.5R25，23.5R25，26.5R25，29.5R25，29.5R29

65 Series (Low Profile Tires )

The H/S aspect ratio is approximately equal to 0.65
The section width, given in millimeters followed by the number 65
Example: 875/65R29
Our size list:  600/65R25，650/65R25，750/65R25， 875/65R29, 35/65R33, 45/65R45

How to Read Tire Sizes?

What does each digital or letter in a tire size mean?

• Overall Diameter (OD)
  “Overall Diameter” is twice the section height of a new tire, plus the nominal rim diameter, including 24-hour inflation growth.

• Overall Width (OW)
  “Overall width” is the width of a new tire, including 24-hour inflation growth, and including protective side ribs, bars or decorations.

• Section Width (SW)
  “Section Width” is the width of a new tire, including 24-hour inflation growth and including normal sidewalls, but nor including protective side ribs, bars, or decorations.

• Static Loaded Radius and Width (SLR, SLW)
  “Static Loaded Radius” is the shortest distance from the axle center to the contact surface of a tire and “Static Loaded Width” is the overall width of a tire, mounted on the approved rim at the specified inflation pressure and placed still and vertically on a flat board, and loaded with the specified load.

• Original Tread Depth (OTD)
  “Original Tread Depth” is the tread depth of a new tire measured at the point of tread-indicator where available or one-fourth the width of the tire crown section from the crown center, including 24-hour inflation growth.