I’m going to let you guy’s in on a little secret. There is only one bearing (I think)that was created solely for the purpose of yoyo’s! That’s the center track bearing. YYF worked with Central bearing company to create this bearing.
Frank Difeo bought bearings and turned them into concave bearings but he spelled it his way. lol
The BC groove bearing and the terrapin groove bearings were created for other machines for other purposes.
All of the flat bearings were created for things like aircraft instrumentation, RC cars and other things. They have just been adapted to yoyo’s.
As far as I know Doc Pop was the first to do beefcake mods and I think he made up the term “beefcake”. Also, if you beefcake 2 half specs the gap width is a tiny bit bigger than it would be with a normal spec bearing.
The Terrapin bearing is definitely done for yoyoing. If you ever even looked at one you would know. Thanks for saying “I think” to show you are just speculating.
I think beefcaking with 2 half specs would be more effective than normal beefcaking since the gap would be the same size as usual, but the two halves would act together as a sort of KonKave bearing.
Also the groove in a 1.5 beefcake would be offcenter.
I always thought that slim bearings were .122 in width or somewhere around there. With normal C bearings being .187 in wide. That’s definately bigger than half. I Dunno, with the only store That I can find with info about them down for now it’s hard to tell.