Components of in-line skates

What Does ABEC Mean?
The ABEC scale is a system for rating the manufacturing tolerances of precision bearings. The system was developed by the Annular Bearing Engineering Committee or Council (ABEC) of the American Bearing Manufacturers Association (ABMA). The American Bearing Manufacturers Association was formerly known as the Anti-Friction Bearing Manufacturers Association.

Bearings rated under the ABEC system are typically called "precision bearings", and they are rated with a number from 1 to 9, with the higher number assigned to bearings manufactured against a higher standard of precision (high number = tighter tolerances = more expensive bearing).

What Does Tolerance Mean?
Tolerance is the amount of variation from an absolute exact measurement that is permitted during the manufacturing process.

Other Rating Systems:
ABEC is only one system for rating bearing tolerances. The International Standards Organization (ISO) and the German National Standards Organization (DIN) use similar scales to rate the precision of bearings. In the ISO and DIN systems, a smaller number means a tighter tolerance and a larger number means a looser tolerance. This is just the opposite of the ABEC system. See the following table for equivalents.

Why to Rotate Your Skate Wheels: Skate wheels usually wear out faster on one edge than the other, and most people wear down some of their wheels faster than others. For example, I wear out my back wheels, and the wheels on my right skate first, and (like most people) I wear out the inside edges of my wheels faster than the outside edges. Rotating your wheels regularly will make them last longer, because they will wear more evenly.

TIP: Pay attention to the way you wear out your wheels. It can help to improve your skating. My wheel-wear pattern tells me to put more power into my left stride, because I'm wearing out the wheels on my right skate faster than the wheels on my left skate.

When to Rotate? You will know it's time to rotate your skate wheels, when you see that one side of your wheels - usually the inside edge - is wearing down more quickly than the other. Another signal is when you can see that some of your wheels are noticeably larger than others, but if you can see this difference, you have probably waited too long!

How to Rotate: Here are three different approaches to rotating your wheels: #1 keeps things simple - you rotate the same wheels, the same way, every time. #2 turns rotating your wheels into an all-day project, and #3 is somewhere in between.

#1 - The Conventional Strategy

The most frequently recommended method for rotating skate wheels is the "1 to 3" and "2 to 4" system. This is what most skate manufacturers recommend, because they want to keep things simple for the average recreational skater. The method: simply flip the wheels over (so they will wear on the opposite edge) and rotate them like this: