What is a Skateboard Bearing?
Skateboard wheels turn freely because of an anti-friction device called a bearing that is inserted between each wheel and axle. The type of bearing used in roller sports equipment is known as a "miniature deep groove ball bearing".   The industry standard size is a 608 bearing, more specifically 8mm x 22mm x 7mm. All of our bearing will fit all wheels in our inventory.

How do Skateboard Bearings Work?
Skateboard bearings reduce the friction between a moving skateboard wheel and a fixed, non-moving skateboared truck axle. Each skateboard wheel requires two bearings - one on each side. A bolt is threaded through the center of each bearing and wheel assembly to attach it to the skateboard truck.

What are ABEC Bearings?
The ABEC scale is a system for rating the manufacturing tolerances of precision bearings. The system was developed by the Annular Bearing Engineering Committee or Council (ABEC) of the American Bearing Manufacturers Association (ABMA). The American Bearing Manufacturers Association was formerly known as the Anti-Friction Bearing Manufacturers Association.

Bearings rated under the ABEC system are typically called "precision bearings", and they are rated with a number from 1 to 9, with the higher number assigned to bearings manufactured against a higher standard of precision (high number = tighter tolerances = more expensive bearing).

What Does Tolerance Mean?
Tolerance is the amount of variation from an absolute exact measurement that is permitted during the manufacturing process.  The higher the Abec rating will result in a higher tolerance bearing.

Other Bearing Rating Systems
ABEC is only one system for rating bearing tolerances. The International Standards Organization (ISO) and the German National Standards Organization (DIN) use similar scales to rate the precision of bearings. In the ISO and DIN systems, a smaller number means a tighter tolerance and a larger number means a looser tolerance. This is just the opposite of the ABEC system.

Lubrication, Oil or Grease?
Bearings lubricated with oil will spin faster in your hand whereas bearings lubricated with grease will spin slower in your hand because oil is thin and it has less resistance than grease. However, oil will not last as long as grease so oiled bearings will need to be lubricated more frequently than greased bearings.  In general,  both oil and grease lubricated bearings will spin fine once they are mounted to the wheels, but oil does require more maintenance and reoiling as it dries up faster.  Grease lubricated bearings will last a little longer between maintenance.

Shields and Rubber Seals
There are 2 types of  bearing covers which are rubber or metal. The metal covers are referred to as shields and commonly known as 608zz.  Rubber seals are commonly known as 608rs or 608-2rs and are basically metal shields coated with a thin rubber material to make the bearing more water proof. The better bearings have removeable shields for cleaning and servicing.