All You Need To Know About Skateboard Bearings

Skateboard bearings can be complicated. Some will be screaming at you that they are the best as they are ABEC 9? Others will say they are better as they are shieldless but what is the truth and as a parent what do you need to know?

skateboard bearing design

The truth about skateboard ABEC ratings

Most skateboard bearings will be marketed around their ABEC rating. The reason for this is that if we see a see a number, we will always assume the higher number is better. Firstly though what is ABEC?

ABEC stands for the Annular Bearing Economic Committee, runs off the tongue, doesn’t it? People have been buying bearings based on their ABEC rating for years. I’m now going to tell you that this is a mistake.

An ABEC rating tells us nothing about the bearings used for skateboards. So never ever pay extra for ABEC 7 over ABEC 5 or 3.

The reason for the different numbers on the ABEC scale is tolerance. The ABEC system goes from 1 to 9 in odd numbers. ABEC 9 is constructed with the tightest tolerances and 1 with the lowest.

The fact that ABEC 9 has the tightest tolerances is probably now making you think about buying them. They must be the best-manufactured version of a skateboard bearing. There is one big problem though.

All skateboard trucks use an axle size od 5/16″, and all skateboard bearings have a bore hole of 8mm. Those of you with a mathematical mind may have worked out that 5/16″ is 7.9375mm. So you have already blown the tolerance of an ABEC 9 bearing out the water.

If you think this is still not a problem and believe that ABEC 9 bearings will roll faster. You might be right, but you will only be able to know this if you are clocking 70mph. I don’t think many people are throwing themselves down handrails at that speed. At skateboard speeds, even with the correct size axle, you would notice no difference between an ABEC 1 bearing and an ABEC 9 bearing

Racing is not important, but races are

Races (cages) are a forgotten part of bearing construction. It is also another part where we as skaters make a poor engineering choice. Most bearings now come with a plastic style race.

The plastic style race is mostly a type of nylon fibreglass construction. We would prefer to recommend a chromium steel style race. A steel race will take more force to break, and your bearings should last longer if you properly care for them.

The reason people go for the plastic style race is that people generally don’t take care of their skateboard bearings. As they don’t clean and lube their bearings, steel races can get rusty. Rusty bearings tend to die, plastic though should not rust.

What about bearing load?

Now we have reached time for a physics style lesson.

When we were getting our ABEC rating, ABEC didn’t bother to check axial loads. Axial loads are side loads. ABEC only checks radial loads. The funny thing is most of also check radial load when we try our bearings.

See, when you grab a wheel and spin it. You then talk about how fast your wheel goes and how long it takes to slow down. That is a radial test. Sadly though it tells us nothing. There is no load on the wheels, unless you and your board weigh nothing, then there will be a load on your board when skating.

A wheel and bearing could spin for hours when spun but still be slow when you are standing on your board.

When skating you will be putting a lot of axial load on your bearings. You will be doing this time and time again. Imagine doing a little powerslide, you are giving your bearings a massive work out.

Your wheel will be flexing about above your bearings. If you have a set of berings made to an exact tolerance, this can be enough to detroy them. They don’t have enough give in their own system. Ironically cheaper bearings will laugh at this treatment.

Spacers are important

There is a small thing designed to help your bearings cope with axial loads, bearing sapcers. Spacers are designed to fit snugly between the bearings in your wheels. Sadly though many skateboard wheels are not made with the correct tolerances for this to work properly either.

You know when you hear wheels screeching across a skatepark? If that person had been running spacers, the chances were you would never have heard that noise. The noise is a warning sound, it menas your bearings are getting more load than they can deal with. That is what leads to bearings exploding.

The spacer stops your bearings from exploding by making them roll parallel to each other at all times. If you have bought an all singing, all danging high ABEC rated bearings then you need that spacer. It may just help keep them alive.

You also want to make sure that you don’t want to lose the speed rings that are on your trucks. When you tighten your nuts, the speed rings will transfer that force through your wheel and not just have it end up on your bearings.

With spacers and speed rings you can just tighten your nuts, and when you can’t do it anymore, you will not need to back off as you would without them. They will now be perfectly in tune for long life.

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