no a crown race wont work, what you need is a comprssion wedge/ring from a threadless headset (the thing with the slit in it) and just put that on top of the upper bearing and then just a small headset spacer on top of that and it is now threadless and you can use it with any threadless compression system you want. stock unsealed headsets really suck though so i would just recommend that you upgrade it to something sealed but whatever that will work.