Get up close and personal with your trailer wheel. The actual size of the rim is imprinted on the face of the wheel, right around the outer lip. It may also be on the backside of the rim. A lot of times when the wheel is painted, the paint will fill in this stamping. When this happens it becomes difficult to read, but at the correct angle is still possible.

If you cannot locate the size stamped in the rim, keep reading!

Start with the tire size. On the sidewall of the tire will be a tire size, Usually written in a standard format. ( 205/75D15 )

• The last number in the tire size is your rim Diameter. So we are looking for a 15″ rim! Were half way done, hope I didn’t loose anyone yet !

Get the second number. So you need a second number now, because 15″ rims generally come in 15×5, 15×5.5, 15×6 or even 15×7.

• The Second number of the rim size is the width. Measured from where the bead sits on one side of the rim, to where it sits on the other.
  • Wheel Offset – The distance between the wheel centerline and the mounting pad.
  • Backspace – The distance between the mounting pad and the outer most part of the wheel’s drum side.
  • Wheel Centerline – The absolute center of the wheel.
  • Bolt Circle Diameter – The diameter of the bolt-holes.
  • Wheel Diameter – The wheel’s diameter where the tire’s bead mounts and creates a seal.
  • Mounting Pad – The portion of the wheel that butts up against the hub face.
  • Drum Side – The side of the wheel facing the trailer drum.
  • Street Side – The visible side of the wheel when mounted correctly.