The wheel hub is the entire nylon or aluminum core that may include spokes at the center of most inline or roller skate wheels. The hub serves as a housing for the wheel’s bearings and spacers and is the central support around which the entire wheel revolves on the axle. There are many kinds of wheels, and the stability and support of the hub or core is critically important to the performance of any of type of wheel that has one.
- Open hub with the spokes showing
- Closed hub with the spokes covered
- No hub or core, usually very small wheels used for aggressive anti-rocker purposes with no need for spokes
Usually, inline skates come with wheel hubs designed to fit a standard 608 sized bearing. But, now some speed and fitness skates use 688 sized micro bearings. Bearing sizes can be switched on an inline skate, if the wheel hub matches the bearing size.