I'm going to show you two ways to clean your [skate bearings] - a fast, easy way that is OK for your bearings, and a longer, more complicated way that is far better for your bearings, but takes a lot longer. You should clean your skateboard bearings if your bearings have slowed down, seem kinda mucky, or if they make a gravely, junky sound when you spin your wheels. To avoid getting to that point, you should really clean your bearings fairly often, even when they are only a little dirty, or just haven't been cleaned in a long time. Cleaning your skate bearings like this from time to time will increase your bearing's lifespan, and improve your skateboarding experience.

There are 5 Abec ratings. An ABEC Rating refers to the Grade of the Bearing in Reference to smoothness and Noise. The quieter the Bearing and the TIGHTER the TOLERANCES between the Radial Ball Run -In and the Run-out - the Higher the Abec Rating. Most Industrial Bearings, such as Grinders - Drills - Routers etc. use Grade Abec-1. An Automotive Manual Transmission would use an Abec 3. Medical equipment might use an ABEC 5. 

The Rocketship to the Moon might use an ABEC 9 - However Jet Engines in the past have used an Abec 1 High Velocity Bearing. Abec is about Quality of Tolerances and an Abec 7 is not faster than an Abec 1 - What makes a Bearing fast is a lighter weight Lubricant. If you use a lightweight Oil it will dissipate faster than grease and you must remember to RE-OIL your Bearings on a regular Basis - Like every Saturday if you skate everyday or every other saturday if you skate 3 times a week - If the Bearings are loud when they spin, they are dry and you need to oil your fag Bearings before they disentigrate from friction.

You should clean your skateboard bearings if your bearings have slowed down, seem kinda mucky, or if they make a gravely, junky sound when you spin your wheels. To avoid getting to that point, you should really clean your timken bearings fairly often, even when they are only a little dirty, or just haven't been cleaned in a long time.

SN520

SN522

SN524