are all Ball bearings created equall?

[slowmotion]

My guess is that you won't notice any difference at all between ball grades. Typically, the balls go in radial bearings that are designed to operate at much heavier loads and and at many thousands of rpm. Even if you pelt downhill ay 100 kph, your wheels are only rotating at a piddling 800 rpm. I would have thought that the quality of the cones is far more critical.

My guess...