My never-ending 1977 50V Moby project needed a new set of rear wheel bearings. I did the job today, and thought I'd share the results.
First off, the bearings were a very common item. Standard #6200Z(Z) ball bearing. $5.82/ea from the local bearing supply house; about $12 total, including tax. This beats the online shops by a mile, which want $15/ea for the bearings, plus S&H.
The old bearings had a metal shield on one side, but open on the other. The new bearings had a shield on both sides - so this is an upgrade. I think the 'Z' suffix means a single shield, and ZZ means two shields.
Put a little propane heat to the hub, and the old bearings drove out easily. There were some metal shavings in the bores, from the original factory installation.. kinda sloppy. I cleaned the debris from the bores before installing the new bearings.
Coated the new bearings & bores with lanolin, and drove them in with a socket that was just slightly smaller than the outer diameter of the bearing. Lanolin has a very high film strength, and is excellent for assembling things with interference fits.
Maybe someone will find this info useful.