Bead Seat :Position where the tire rests on the inside of the rim and seals.
Bolt Circle :The diameter at which bolt holes are located for mounting purposes.
Bolt Pattern :The mounting pattern including the number of bolt holes, the bolt circle, and the pilot hole diameter.
Capacity: Load rating given to a wheel. Based on a single wheel application. Capacities are based on applicable SAE standards.
Center Line: One half the rim width.
Chamfer: Breaks in the sharp edges of the mounting bolt holes to assist in assembly.
Drop Center :The inside diameter of the rim where the center disc is normally welded to the rim. Also referred to as the rim well or deep well.
Inset/Outset :Inset is positive offset, in which the center line of the wheel is inboard from the mounting face of the disc. Outset is negative offset, in which the center line of the wheel is located outboard from the mounting face of the disc.
Non-reversible Wheel :A wheel that will mount with one side of the disc face only.
Pilot Hole :Nominal diameter of the center hole that fits over the hub or axle.
Reversible Wheel: A wheel that can be mounted with either side of the disc face to the hub face.
Rim Diameter :Nominal diameter measured from the bead seat.
Rim Flange :The edge of the rim that has a larger diameter than the tire bead designed to support the tire.
Rim Profile: The rim shape as defined by the Tire and Rim Association.
Rim Width: Nominal width measured between rim flanges.
SAE: Society of Automotive Engineers. When a wheel conforms to published SAE specifications, it is assigned a number.
Tubeless: Wheel or Rim A single piece wheel or rim with a drop center (rim well) designed for use with tubeless tires.
Valve :Guard Device on the wheel to protect the valve stem.
Valve Hole: A round hole in a single piece rim to accommodate the valve stem.
Weight Holes :Additional holes placed in the disc for the attachment of wheel weights.
Wheel: A rim combined with a center disc which has bolt holes for attaching to a vehicle.
