ORIGINAL: lfinney
heres some real tech about ABEC, for those who really want to know facts versus old wives tales
the most crude, the least precise, the most durable and the cheapest.
ABEC 3 is what most cheap complete skateboards come with, especially skateboards from China. ABEC 3 bearings will work for most skateboarding, but won't roll very smoothly or fast.
ABEC 5 bearings are the norm in skateboarding. You get a reasonable amount of speed, and at a reasonable cost. However, there are lots of people who argue that the skateboarding industry is lying, and that most ABEC 5 skateboard bearings you see aren't actually built to ABEC 5 standards...
ABEC 7 bearings would be very fast and smooth, but very expensive. Plus, you start to run the risk of needlessly damaging them if you skate hard or aggressively. Also, if you are buying cheap ABEC 7 bearings made in China, you are probably being lied to (read The Truth about Skateboard Bearings.
ABEC 9 and higher bearings would be ridiculous to use in a skateboard, unless you are doing downhill luge style skating, or something else where your goal is to go insanely fast. If you aren't spending a fortune on these bearings, then don't trust that they are in fact ABEC 9!
The ABEC rating of a bearing is determined by asking these four questions:
How close is the bore to 8mm in microns (a micron is one millionth of a meter)?
How close is the outer diameter to 22 in microns?
How close is the width to 7mm in microns?
What's the rotating accuracy in microns?
knowledge is power abec rating have nothing to do with noise as posted earlier in this thread
A ABEC 1 bearing will be louder than a ABEC 3 bearing and so on. Buy a real ABEC 9 bearing and spin it then spin a ABEC 5 bearing. you might be supprised!
Ifinny lol you crack me up. You spend two seconds looking up bearings on the net. you copy and paste the first thing you find on Yahoo. Your copy and paste has no credibility at all. its a skate board shop that sells bearings. i used to play roller hockey. I know all about bearings used in these and skate boards. I also work on 270 million dollar jets for a living. i think i know bearings. i will Quote you again here "How close is the bore to 8mm in microns (a micron is one millionth of a meter)?
How close is the outer diameter to 22 in microns?
How close is the width to 7mm in microns?
What's the rotating accuracy in microns?"
Your quote here only pertain to one size bearing. A bearing of 22mm outside dia. inner race is 8mm and the total bearing is 7mm wide lol Is that a skate board bearing your to funny dude.
Here is a Quote/copy paste for the readers here.
ABEC scale
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The ABEC scale is an industry accepted standard for the tolerances of a ball bearing. It was developed by the Annular Bearing Engineering Committee (ABEC) of the American Bearing Manufacturers Association (ABMA). There are five classes from largest to smallest tolerances: 1, 3, 5, 7, and 9. The higher ABEC classes provide better precision, efficiency,[citation needed] and greater speed capabilities, but do not necessarily make the components spin faster.[1] The ABEC rating does not specify many other critical factors, such as smoothness of the rolling contact surfaces, ball precision or quality/type of steel used.
The bearing material is not specified in the ABEC grades. Bearings not conforming to at least ABEC 1 can not be classified as precision bearings as their tolerances are too loose.
The scale is designed to allow a user to make an informed decision about the type of bearing they are purchasing. High rated bearings are intended for precision applications like aircraft instruments or surgical equipment. Lower grades are intended for the vast majority of applications such as vehicles, mechanical hobbies, skates, skateboards, fishing reels and industrial machinery. High ABEC rated bearings allow optimal performance of critical applications requiring very high RPM and smooth operation.
ISO's equivalent standard is ISO 492.
ABEC 1
class 6
ABEC 3
class 6
ABEC 5
class 5
ABEC 7
class 4
ABEC 9
class 2
There are a number of factors covered by the ABEC grades. One is the eccentricity (roundness) of the track in the inner ring. The figures given below is the maximum eccentricity allowable.
ABEC 1: 0.0075mm (0.000295")
ABEC 3: 0.0050mm (0.000197")
ABEC 5: 0.0035mm (0.000138")
ABEC 7: 0.0025mm (0.000098")
ABEC 9: 0.0012mm (0.000047")
now if you readers what to know tons more on bearing goto the ABMA website. register and learn a bunch. now anytime you guys do a search on the net for information you need to make sure the info presented is accurate, current and most of all relevant. make sure the author has expertise on the topic he is writing about. A skate board shop talking about bearings he sells doesnt match any of these things. just like I dont but i i know crap when I see it. i have seen where some places will sell you a ABEC 7 or 9 bearing and give you 50% off. you are like whoa i have to have that i will go so fast lol. He knows that you cant tell. the ABEC 3 bearigs are the best for skate boards by the way. there is so much dirt and dust on the roads they with the higher clearneces they have they will last longer. sure a ABEC 5 or 7 might go a tad faster but it will wear out faster hence why those shops will sell them to you. Anyway Iffinny no negative just that copy and post wasnt good. i have seen some much better from you on here.
Flyer send a pic of plane to my email ok its
[email protected] i will help you as best i can. i bet that guy has modded his engine some if have to run stock muffler. talk to him and see if he will give his ground rpm.. then go up and check his prop someday.