Originally Posted by
HillRider
I believe they are called "Zero Stack" I assume the bearings have to match the configuration of the pressed in cups if not the flairs in the headtube.
Sounds right. These seem to be simply a variation of the pressed-in concept. From the photo, it looks like he's replacing the entire headset, so internal details wouldn't matter. Otherwise I don't know if folks are supposed to replace only the bearings, like with integrated, or complete units like Pressed-in versions.