Overhauled hubs: still some noise I've just, for the first time, finished servicing the hubs on my bicycle. They are of the cup &amp; cone type (Shimano). The cones of the front hub where pitted so I got them replaced, along with the bearing balls. The cups still looked smooth. I've packed them with a generous amount of grease and adjusted them for minimal play when out of the fork / no play when the QR is closed.

When I turn the axle by hand it feels smooth. However, with the front wheel installed, when I lift the front and give the wheel a spin, there is some clicking/scratching noise. It only seems to be present when running at a certain speed. My guess is these are the bearings touching each other? Is this normal?
Are you sure you've got the cones locked against the lock nuts correctly? I have a front wheel on which it's not possible to tighten the lock nuts against the cones, and as a result it will almost entirely seize after about 5 miles.