Disc rim VS traditional laced rim?

I learned that a solid disc will always spin faster due to the center of gravity.

You think this would apply verywell with a disc rim?

I've done multiple tests in class, And it's so far been proven true. I would do the test with a disc and traditional lace. But that means i need a mirror surface large enough for the rim, And i would need to spin the rims on its lip not tires ):