Those suck. Unfortunately, they're becoming more prevalent. However, you
should be able to get a retrofit kit, to install a standard headset.

Well, this summer, we did get problems with Elisabeth´s headset in Frisco.
http://w1.185.telia.com/~u18515267/Coloradoeast2.jpg

Although there are some pretty good bike shops in Colorado we were told that
it would be at least a week for them to get the necessary bearing and tools
from Klein. As the darn bike was getting dangerous we phoned Titus who had
an xs Riddler in stock and could overnight it to Salida where we could pick
it up at Absolutebikes the next day. Absolute helped us move everything that
could be salvaged over to the Riddler. She opted for a CK headset for it.
The Kleins may be sexy with idiocsyncratic solutions but it can surely cost
a lot. We had the choice between not biking for week on our cycle holiday,
or buying a new frame, fork, front deraileur, headset, stem, and saddlepost.
We did the latter http://w1.185.telia.com/~u18515267/Raiderridge1.JPG

With regard to retrofiting, there are adapters. They are made by a German
precision manufacturer, Reset Racing http://www.reset-racing.com/ they have
several sets for Kleins http://www.reset-racing.de/reset/reset2.htm
http://www.reset-racing.de/reset/reset2a.htm. Seems to be a fairly
complicated operation, one for which you need a mechanic with plenty of
experience of working on Kleins. At that Reset Racing does not "accept
credit cards yet."

The Adroit is still in Salida. Absolutebikes has since fixed the headset,
got a new bearing and the special tools you need from Trek/Fisher. We are
trying to decide what to do with. Apart from the flaw it is a wonderfully
handling frame.

Per
http://user.tninet.se/~ipg289h/fu99/MTB.html