Originally Posted by
HillRider
Yes, some Campy hubs had split adjustable cones that allowed you to do the final adjustment with the wheel fully clamped in the dropouts and tighten the cone until the play at the rim just disappeared. Then you locked the cone in place with a set screw that pinched the sides of the cone together. A great system and too bad it wasn't more common.
I believe it is the carrier of the cone or bearing that is split, otherwise the balls would be riding over the split and erode the ball track there. Chris King has a similar system, Mavic's just uses a friction fir between the carrier and the axle.
But the goal of a free as possible bearing with no (angular contact) or minimal (radial contact) slop is a real benefit to bearing life. Regardless of whether a rider will feel it as they ride. Andy