I've never seen those before, I have seen
these in person and believe they are serviceable. Yours look like an older model obviously.
*10 minutes later*
I did you a favor. I called Zipp, they said they made those a ways back and don't recommend servicing them ... they are cartrige bearings and they probably don't have the parts for them anymore. But, the guy I talked to said that there was another dude there (but he had left for the day) that might be able to suggest a possible solution. ?