Roller skate bearings.

If I was looking for bearings for roller skates then I would look at a supplier such as Simply Bearings, they have a range of bearing grades available, have used them for different bearings and found their product to be good and prices are sensible. Dave W

A place where I worked in the 70's had quite a lot of sets of radio gear that used a quite nice fan with a machined alloy case and blades to suck the hot air out. The trouble was that they chopped out the bearings quite frequently. One of the bosses had a son who was into speed skating at the national level. Whenever we found a fan that had gone noisy, we would change out both the bearings and put in new ones. The old ones had to go to the boss guy so that he could put the OK ones into the skates, since they were the exact same size. Usually only one bearings had actually failed, you could feel the grittiness where they had gone through the hardening. I suggested that perhaps if the bearing at one end of the fan had gone, the other might not be far behind and that it might not be a fun experience to have a bearing decide to seize up when skating as fast as possible, but it seemed they were OK with that risk.

John

If ABEC is a tolerance then it has little to do with quality, only clearance Etc. Noel.

I bought a very nice set off fleabay for a tenner, to repair the wife's wheelchair front casters, worked a treat.

Edited By Bernard Wright on 13/02/2021 12:33:03

"ABEC 11" is a branding. The ABEC scale stops a 9.

I'd have thought the clearance (often shown with C and a digit) of the bearing might be as least as important as the tolerance rating, though there will be some inter-relation, difficult to get super tight clearances if the tolerance limit for the parts is wide.

Your right David, for electric motors C3 is often the fit. Noel.

Thanks for replies,which reinforce my gut feeling that the benefit of these super-expensive bearings is largely, or perhaps wholly, psychological.

As far as I can gather the ABEC specs relate to the tolerances on the inner and outer diameters of the bearings. My daughter pressed her bearings into the plastic wheels by hand then mounted them on to the nominally 8mm axles. She is a slightly built woman, so I doubt that she would have been able to achieve the force necessary to get a tight interference fit to the axle - which is essential to prevent 'creep', when there is movement between the inner race and the axle which can lead to abrasion. And what is the tolerance on the axle diameter I wonder!

MichaelG thought the claim on the Slick Willies website:

[quote]

When you get dirt into your Ceramic Reds, the ceramic balls will help to re-polish the steel races flat again, providing a self-healing benefit because ceramic balls are so much harder than steel.

[/quote]

was 'questionable'. I think that is a characteristically polite way of saying 'wrong' whilst admitting the possibility of error.

I had a look at the SKF website and they go into all this in mind boggling detail - it's pretty complicated. More than I can cope with at the moment, but enough to convince me that the claims made by the skate people are - well - questionable.

It's just marketing nonsense isn't it?

Robin.

Edited By Robin Graham on 14/02/2021 02:35:26

Edited By Robin Graham on 14/02/2021 02:36:17

I know it's different applications, but.............. When I used to be responsible for machine tool specification and acquisition, I was given the following advice. Ceramic spindle bearings are fine in an environment where there will be no machine "crashes", this would apply to a production environment where all tooling, hard and soft, all processes etc are proven. However in a "jobbing" environment where the frequency of new tasks with unproven tooling will be far higher, then ceramic bearings are not advised. Simply because they have a very low tolerance for shock. In a jobbing environment steel bearings are advised.

This recommendation was to avoid the wrecking of machine tool spindles, which at the time, 15 or so years ago varied in cost between AU$10,000 for a Bridgeport VMC to over AU$40,000 for a Makino horizontal mill.

Now I'm not sure of the likelihood of shock loadings on skates, but I would imagine that they are fairly high. I'm also not sure of the relative cost of steel bearings vs ceramic bearings, and the cost of changing knackered bearings for good ones. However they are probably things which should be considered.

No doubt someone will shoot me down in flames with ..."I've had ceramic bearings on my skates, skate board, in lines for the last 20 years, skated around the World, up mountains across rivers, across the Sahara, never had a problem" To which my response would be " Well done"

cheers

Bill

Absolutely. Two friends of mine set up a hi-fi company in the seventies using direct-drive speakers which I understand was ground-breaking stuff at the time. Listening to direct-cut discs (who remembers them?) through their equipment was a revelation. They marketed it at cost plus a sensible mark-up and sales were very poor. They then added some bullshine to the marketing and raised their price above the conventional competition and sales took off. It had as much to do with the customer's bragging rights as the quality of the sound.

George B.

The big boy bearing manufacturers like FAG and SKF make top quality and probably can't be bettered. I suspect anything above their prices is to cover extra marketing.

But the £200 are super accurate ceramic balls - not easy to make I suspect, and so you are getting something for your money. You might not need that something. I wonder who actually makes them, and for what purpose?

I just got set of 8 ABEC-9 from amazon because it was cheaper than buying 2 of the cheapest from BearingBoys (after delivery costs, 'casue I got Prime)

And there is a big difference in quality, longevity between cheapest and good SKF/FAG. I use skateboard wheels on my belt grinder and cheap lasts tens of hours; expensive... I haven't worn them out yet (probably mostly due to the quality of the seals).

I bet the 8mm version of these will make the £200 ones look cheap.

https://www.bearingboys.co.uk/SKF-High-Temperature/62012ZVA228-SKF-High-Temperature-Ball-Bearing-12mm-x-32mm-x-10mm-92754-p

Or even 8 of these is going to set you back 

£427.20

https://simplybearings.co.uk/shop/p17720/SKF-6082RSLTN9HC5C3WTF1-Ceramic-Hybrid-Ball-Bearing-with-SiN4-Balls-and-Two-Low-Friction-Seals-8x22x7mm/product_info.html?backstep=1

Edited By jaCK Hobson on 14/02/2021 16:59:23

Edited By jaCK Hobson on 14/02/2021 17:00:32

Edited By jaCK Hobson on 14/02/2021 17:07:11

Edited By jaCK Hobson on 14/02/2021 17:20:28

Being a past roller blade enthusiast heres my two cents. The ABEC rating when it comes down to it effects the free rolling speed on those wheels. I had ABEC 3 bearings in my blades and when I changed them out to ABEC 7 I nearly fell on my ass they were so free rolling. The tighter precision effects the speed you are able to attain. Makes it a little more unstable then the slower more steady ABEC3 bearings.

Johnny O

Surely ceramic ball races were originally introduced for gas turbines as the hey coped with the dirty atmosphere that the engine breathed. Ceramic balls crush the foreign bodies where steel balls skid.