Each skating wheel fits two bearings. The standard size is a 608-bearing (inside diameter d = 8 mm, diamater D = 22 mm, width = 7 mm).
|Steel||Popular and most common bearing|
|Stainless steel||100% rustproof. Your everyday choice|
|Hybrid||Steel bearing with ceramic balls. Very fast and 100% rustproof|
|Ceramic||Lightweight and fast. Only for speedskaters|
The cover protects the bearing from dirt and dust.
RS-covers are made of plastic/rubber and are easy to remove. Z-covers are made of steel and offers a smooth operation but are difficult to remove.
The ABEC scale is an industry accepted standard for the tolerances of a ball bearing. It was developed by the Annular Bearing Engineering Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). There are five classes from largest to smallest tolerances: 1, 3, 5, 7, and 9. The higher ABEC classes provide better precision, efficiency and greater speed capabilities, but do not necessarily make the components spin faster. The ABEC rating does not specify many other critical factors, such as smoothness of the rolling contact surfaces, ball precision or quality/type of steel used.
The bearing material is not specified in the ABEC grades. Bearings not conforming to at least ABEC 1 can not be classified as precision bearings as their tolerances are too loose. (cf. wikipedia.org)
For a bearing to operate properly, it needs to be lubricated. Most common ist oil or grease. Low-viscosity lubricants are faster but will also evaporate faster than a high-viscosity lubricant like grease. We recommend oi for races and grease for training.
The cage carries no load and serves only to maintain ball position. Without the cage, the balls would eventually drift out of position during operation, causing the bearing to fail (cf. wikipedia.org).