There's a lot of emphasis put on skate bearings and since I just launched the Go Project brand; with bearings as it's the flagship product, it's probably quite apt for me to make an informative post in regards to inline skate bearings [insert pun about 'finding your bearings']

This could be a really long piece of writing if I wanted it to be, but if you were born after the internet was invented you've probably got the attention span of a 5-year-old on Pick 'n' Mix so I'll just throw some quick bullet points down...

bearing-montage

How it works:

  • I'm not sure if many of you have ever thought about bearings at a very basic physical level. But bearings work by 7 tiny balls rolling around a tiny racetrack. The balls can only move in an exact circular motion because they are held into a groove by their surrounding parts.
  • Some bearings use 6 balls instead of 7. There is less friction with 6 (even though the balls are bigger because it's only the very tip of the ball which touches the other parts of the bearing). The balls are bigger so the bearing is stronger where it needs to be. Twincam makes bearings with 6 balls and makes them for companies like K2, Seba, and Powerslide. The Go Project Richie Eisler bearings are also 6-ball (but we used an all-new factory)
  • As you know, many bearings use the ABEC scale to rate the standard of their bearing models. However many of the best companies understand that 'axial' loads imposed by skating make the ABEC rating obsolete. Axial is like a twisting, side-on load. Bones, Go Project and ThemGoods all recognize this at some level.
  • In a nutshellthe rating is pretty much based on how 'precisely' everything is made, like how round the bearing race/groove is and how exact the size of the hole through the middle is, all measured in Microns (really tiny). The hole size is again, virtually invalid because the factory who made your frames and bolts probably didn't give a shit about how many 'Microns' thick the machining of their hardware is.
  • Skate bearings feature a light oil/cream/lubricant inside. It mainly helps to keep things moving once the bearing is contaminated with grit/dirt/dust (pretty much as soon as you roll along). It has to be a light oil otherwise performance will be hindered. More on this further down.

p-bearing

 

 

Bearing Myths:

  • A higher ABEC rated bearing does not necessarily denote that the bearing will spin faster. It simply means the bearing will be able to withstand a greater amount of revolutions per second.
  • A higher ABEC rating does not necessarily mean the bearing is better because the ABEC rating does not take into account certain factors like quality of materials used.
  • If a bearing spins for ages in your hands it's not always a sign it's the best bearing. A lot of the time it spins for this long because the components are loose (ie it's all wobbly side to side!). Once fitted into the wheel and frame this type of bearing will have a similar effect to a 'buckled' bicycle wheel. As you can imagine this isn't very efficient for your overall speed and also means your bearings will deteriorate very quickly.
  • Trying to judge your bearing's performance when the bearings are unloaded (ie when you haven't got any weight on them) is not really a fair representation, as seen in our video below. The bearings quite simply play a very small part in the overall rolling resistance once you are using them in a real-life situation.
  • If bearings are listed as 'waterproof' and they are cheap then don't believe it. Some companies think that putting a rubber shield on the bearing constitutes them being water-tight. That's absolute rubbish of course because if it was sealed water-tight then it wouldn't spin (the parts have to move individually of each other). Water will wash away your lube and make your bearings crunchy anyway. The only waterproof bearings I can think of would be fully ceramic so no parts can rust. You'll still want to dry them out and re-lube when you get home after a wet skate though otherwisethey'll be noisy.
  • Oiling your bearings isn't going to turn them brand new again. In factthe oil you use for doing it will probably cost you half of a new set of bearings anyway, add that to the time you spent doing it (what do you value your time at?) and it's probably not cost-effective to do. Using normal household/garage oils will likely act as an adhesive for grit and gunk so will clog up your bearings. Most oils generally tend to have quite a thick consistency at low temperatures (like in skating) so will make your bearings more sluggish in the long run. If you truly feel the need to clean your bearings, 'cos maybe you've got those next-level baller ones, then I've been told you should clean them with aviation gasoline and then put some skate bearing specific speed cream on them afterward... but then if you have access to aviation gasoline you probably have some better things to do with your time.
  • ABEC stands for Annular Bearing Engineering Committee. For quite a long time I thought this meant that there's a bunch of people in the States somewhere sitting around a table once a year talking about how to best judge their washing machine components. Turns out annular means 'ring-shaped'. [My girlfriend just pointed out that the two words are probably derived from the same meaning (ie meaning 'Full Circle'). Interesting ...Or not. Your call.]
  • There's no such thing as an ABEC 11 rating. That's just the name of some skateboarding company.

ABEC11NoSkoolz_65mmLRG
Our video showing a free-spinning Full Ceramic bearing, but spinning an 'unloaded' bearing like this is not always a true representation of performance:

 

 

 

 

 

Components:

I stole the cross-section diagram below from an advert for NMB bearings in the first ever issue of Unity magazine from July 1996. The diagram shows the different parts of a skate bearing. I updated the text:

bearing-diagram

That's all for now! Just some food for thought for all you over-thinking engineering keenos.