The EZO bearings that comes in SPYY yo-yos are not made only for yo-yos, they come from a company called Sapporo/Ezo. They play well, so, like Samad said, if it fits, try it!
Whoops, I meant that the company makes their bearings only for their yo-yos, like the SPEC for yoyofactory yo-yos. I have not seen SPEC’s anywhere else (correct me if I’m wrong).
A wheel bearing is a wheel bearing. There is minimal difference between two bearings of the same size. It would be no different than a SPEC vs YYJ bearings.
I hope you noticed that I said bearings aren’t made for yoyo’s. They are made for machines and RC cars and things like that. NOT for yoyo’s. Just an FYI thats all.
I think a better way to say this is that they were not originally intended for yo-yos. I’m pretty sure I know what you mean, but there are some bearings that really are made specifically for yo-yos. Dif-e-yos KK is a perfect example.
Back in I think it was 1995 or so before Dif’s I worked at a company that made machines that spooled fiberoptic cable. We had konkave bearings on that so…
I guess I could agree that yoyo makers are starting to ask bearing makers ways of improving freespin times. The ten ball was before onedrop though.