Skateboard Bearing Parts
- Category: Bearings
Skateboard bearings are assembled using 5 different parts, but not every bearing uses the same type of parts. There are variations between bearing balls, ball retainer, and closures (seals and shields). Knowing the different parts involved can assist you with making more informed decision when selecting bearing sets. Also, knowing the purpose for each part can help when choosing the right set based on price, speed, durability, and serviceability.
Standard Bearing parts:
- Seven Steel Balls
- One Or Two Closures.
- Outer Ring
- Inner Ring
- Ball Retainer/Cage
Beacuse there are variations of a few bearing parts to choose from not every bearing set in a skate shop may be the same. With the exception of cermaic balls, these variations do little to effect price. Price is usually determined by brand name, and the quality of material and manufacturing.
It is believed that ceramic balls are superior to the standard steel balls. Ceramic balls are significantly more expensive than steel balls, but this does not directly translate to a higher quality product. For more information about the differences and values between steel and ceramic balls see the page on Cermaic VS Steel.
Closures (Rubber Seals and Metal Shields)
Bearing closures are like walls that protect the bearing from outside debris, and help keep lubricants inside the bearing. Typically, skateboard bearings come with one closure, which is etiher a bunna rubber seal or metal shield. In rare occurances metal shields are replaced with plastic shields. There are 2 types of metal shields– pressed in non-removable metal shields, and removable metal shields held in with a C-ring. Pressed in shields do not allow for easy bearing maintenance.
Bunna rubber seals are considered a better choice for sealing lubricants in the bearing, and for not allowing contaminants, like dirt and moisture, to enter the bearing. There are two types of rubber seals. Located on the inside edge of the bearing seal is a thin flap of rubber. This flap is either lightly touching or not touching the inner ring of the bearing. These are known as "light contact rubber seals" or "non-contact rubber seals". Light contact rubber seals do a better job at protecting the bearing and keeping lubricant in. This light contact does not create any noticeable reduction in speed while skateboarding. For more information see the page on Bearing Seals & Shields.
Ball retainers are used to space out the balls evenly around the raceway. Nylon ball retainers can offer lower coefficient of friction than steel or brass retainers. Nylon retianers are better suited for speed, but are not as durable as metal retainers, which are better suited for the abuse brought on by street skating.
For more information about bearings including, ABEC, Swiss, and ceramic bearings watch the video below.