ABEC Rating - ABEC stands for Annular Bearing Engineers Committee, the organization that developed the internationally recognized scale of bearing quality. In-line skate wheels are rated on the so-called Shore "A" ABEC scale.
Bearing - An encasement containing ball bearings often shielded and pre-packed in grease.
Core - Centre portion of a single wheel, comprising the bearings, spacers, and axle. Holds bearings in place.
Diameter - The size of a skate wheel, measured in millimetres.
Durometer Rating - The method of classifying skate wheels according to their hardness. The larger the durometer number, the harder the wheel.
Hub - The centre of a skate wheel, including the core, bearings, and spacers.
Profile - The outline of sidecut of the rolling surface; shows how much of the wheel is actually in contact with the skating surface. Pointed narrow wheels take up less running surface, offering higher speeds and quicker steering. Wider radius wheels provide more stability at slower speeds.
