Campagnolo has always made nice hubs so I enjoyed overhauling and lacing these to Archetype rims. The rear hub needed help with pitted cones and sticky pawls but now it’s as good as new. The loose ball bearings were replaced on both hubs, which should be done as part of periodic maintenance. In the same way that regularly replacing your chain extends the life of cassettes and chainrings, replacing loose ball bearings saves your cups and cones. If you have nice hubs, take care of them and they will last forever. Good hubs can last through several sets of rims.
Blog: Hub Overhauls
A cartridge bearing should have an interference fit with its hub bore. Some hubs hold their bearings firmly and others are too loose. At first glance a slip fit seems simpler for the DIY mechanic but a slip fit can allow slight play in the wheel. Play is no good because it’s your cue adjustment is lost or bearings are worn. Unnecessary play can damage hubs.
These hubs are a good example — out of the box I found the bearings slightly loose. In cases like this I re-install bearings with a thin layer of Loctite 641 applied to the outer races. Loctite makes a variety of industrial bearing retainer compounds but I use 641 because it’s a low viscosity formula that allows for thin applications. It’s the lowest strength sold, which means bearings can be pulled easily in the future.