ABEC bearing ratings are the standard that is used to identify the tolerances a bearing was built with. The ABEC or "Annual Bearing Engineers Committee," was established to set the specifications and tolerances for all bearings. This committee rates every companies bearings so they can market with the respective rating.
In longboarding, the most popular and commonly used bearing is the ABEC 7. But what does this specifically mean? ABEC ratings rank from 1-9 with 1 being the most loose performance, and 9 being extremely precise. ABEC 7 is considered very high performance.
There are many common misconceptions about what the ABEC rating really means. First off, it's not as big of a deal to have a lower rating as most skaters would believe. The axle and bearing interface is usually a little off in general, diminishing any gains achieved by a super high ABEC bearing. The other important factor is how tight the bearing fits into the wheel. The idea with these ratings is that a higher one means the bearings are a near perfectly smooth fit. If your wheels and axle fits are loose all gains are lost.
What should skaters look for?
The average skater should focus the most on the materials used in the bearing, and what type of lubrication is applied.
It is said that Chromium bearings are the best for skateboarding based on durability and performance. When it comes to lubrication, there's advantages and disadvantages to both the main types. The two types are heavy grease, or light oil. The light oil type was started by Powell and is the premier choice today. It spins faster and attracts less dust than the older grease style. Grease attracts more dust but helps the components last longer. It also makes the wheels spin slower (especially at lower temperatures) which is a serious drawback.
How does this affect longboards?
First and foremost, anything above an ABEC 3 is not necessary for the average skater. The high precision can be very important for downhill skaters exceeding 70 MPH, and they need a top of the line bearing. But the fact of the matter is that the axial load (side load from carving/turning on a board) actually damages the average skaters bearings over time. A very precise bearing has little wiggle room, which causes them to perform far worse and at a faster rate than a lower rated bearing.
So should you get a lower rated bearing for skateboarding if you aren't setting speed records? To be honest you won't pay much more for an ABEC 7 bearing, and it seems that companies use better materials in the higher rated bearings as well. It makes sense to just go for the better bearing, but you need to keep them clean! Dirty bearings will slow you down no matter what ABEC you are rolling on. That being said, an ABEC 9 bearing is really only necessary for the top speed skaters. There's a reason ABEC 7 is the most common. It's just the right tolerance and made with the right materials for durability.
Hopefully this helps to clear up the ABEC system and makes bearings simpler to understand. Now go spread the word to all those kids that think they can skate faster than you because they have ABEC 9's....