I recently came across a site that sold industrial ball-bearings. There was a whole section for yoyo ball bearings. Some are for yomega, some are for duncans, some are for yyjs, etc. Most of them are in 10 packs, but I found a 1-paack that supposedly is a size C bearing (.250 x .500 x .187) that fits yyjs and the like.
The link to that: http://www.vxb.com/page/bearings/PROD/YoYo/R188ZZ-1
I’m sure they’re nothing special, just different. That 71,000 rpm is what it can handle before it burns/breaks apart, not that it will automatically spin that fast.
I’ll probably get some replacement bearings for my yoyos ;D
That seems like the only place where I can get bearings for my maverick. (It’s slightly smaller than size C bearings)