eBay Guides - Skateboard Bearing Buyers Guide And Installation

Skateboard Bearings go inside the skateboard wheel and make the wheels spin, and in turn, makes the skateboard go.

There are two types of shields, "the sides of the bearings", that protect the ball bearing inside. Steel and rubber. Neither are better nor worse. It's all preference. Steel shield are the best if you do not intend to spend two hours cleaning your ball bearings inside the bearing cage. Some low end bearings with rubber shields don't last very long. The shields pop off and or rub up against the ball bearings causing friction and thus slowing you down. They can also fall off, which is not a good thing.
There are two different types of lubrication used in bearings; grease and oil. Oil may spin faster when holding the bearing in your hand, but in a skateboard wheel, they both spin the same. Grease simply lasts longer inside the bearing. Oil escapes and/or dries up in a matter of weeks. So both are fast, but grease lasts longer. Some high end bearings use special lubrication inside the bearings.
The ABEC rating system has been around for the last 30-40 years. The purpose of the ABEC committee (Annular Bearing Engineers Committee) is not to test every manufacturer's bearings and proclaim them good or bad, but to establish dimensions, tolerances, and noise standards for bearings in an attempt to aid industrial bearing manufacturers and users in the selection of bearings for general applications. However, since every bearing is used in a different manner and environment, bearings should be redesigned or "customized" for special uses (like skateboarding). The ABEC rating system includes grades 1,3,5,7, and 9. The higher the ABEC rating, the tighter the tolerances are, making the bearing a more precision part. High precision and small tolerances are required for bearings to function at very high RPM, in products like high speed routers that must spin at 20 to 30,000 RPM. In an application like this, an ABEC-7 or 9 bearing rating may be appropriate. However, a skateboard with 54mm wheels turning 20,000 RPM with be traveling about 127 MPH. Since virtually all skating is done under 30 MPH, the realistic maximum RPM your skate bearings will see is about 4700 RPM and probably 90% of skating occurs under 2000 RPM. Thus, very high precision is not required at skating speeds. The ABEC rating system ignores side loading, impact resistance, materials selection, and grade. Some will argue that after riding your skateboard for a day or two, the precision that your bearing had when you first bought it is long gone. Since the skateboard has been banged around and abused, whatever tolerance was inside the bearing is gone.

Bottom Line: The ABEC rating system has very little to do with how fast the bearings are in your skateboard. You may be better off saving some money and just sticking with ABEC 3 Bearings. We use SL Bearings with steel shields and grease packed in most of our Skateboard Completes or you can simply buy the bearings seperately.

Installation:

1. Slip one bearing on the axle of the truck.

2. Position the skateboard truck so that the axle is verticle to the ground. (one end of the axle is touching the ground)

3. Take the wheel and place it over the bearing.

4. Press the wheel down over the bearing until it's completely flush with the inside of the bearing sleeve in the wheel. (the bearing will not go in any further.)