You can service them by popping the seals, cleaning and (obviously only using the special grease) regrease them though. But it's way easier to just whack new bearings into something cheaper and there's really no benefit in having such wonderfully engineered bearings in something that just goes left and right a little bit. Obviously if you've got the money for the hubs and want matchy matchy then they're very nice but completely unnecessary.
You can service them by popping the seals, cleaning and (obviously only using the special grease) regrease them though. But it's way easier to just whack new bearings into something cheaper and there's really no benefit in having such wonderfully engineered bearings in something that just goes left and right a little bit. Obviously if you've got the money for the hubs and want matchy matchy then they're very nice but completely unnecessary.