I'm hunting for bearings myself right now and also a bit confused by offerings on ebay. I know the idea is to go for generic skate bearings but most list as ABEC-7 or -8 or -9. None of the listings specify what 'ABEC' means and I can't find a definition using search engines. Is the ABEC-# some measure of quality, or is it a inner/outer diameter spec? I'm guessing quality, but what would be recommended for the jgro plans?
Basically ABEC-1 is the worst and ABEC-9 is the best. Seems others recommend ABEC-5/7 for tight precision but for JGRO machines it sounds like pretty much any grade will work.
Here is a skate bearing place that I found. www.skates.com
Look at the menu on the left side. Click on bearings and then when the new page loads you can sort the bearings by price LOW TO HIGH with the little pull down menu. The cheapest bearing shown is an ABEC 5 and is only 99 cents each. They have an ABEC 7 for $1.85 each and an ABEC 9 for $1.99
I bought ABEC 7s for my JGRO on eBay. I found them for just $14.99 for a set of 32. There was $3.60 shipping added. Another fellow had ABEC 3s but his price was just a few dollars cheaper due to high shipping costs. The ABEC7s I bought have superior teflon seals and that is the main reason I bought them. $1.66 each for 7s? Thats just silly. In the words of Monty Python, "Run away, run away." (Knight slang for charge)