My old headset was loosy and feeling very instable.
So I removed it, I got this:
and I'd want to install it.
I am wondering what is the right way to install the two pieces on the right. I know the crown ring (second from right) has to be installed on the fork (I removed the old one). But I don't know what to do with the plastic ring. Should I put it before the crown ring? Should I put it afterwards? What is its purpose? (actually I am having and hard time realizing how everything works since the ball bearings are sealed and they don't have to slide on the crown ring itself).
I bought this PVC tube to install the ring, for reference:
And I think to hammer it down with it.
Thanks for your help!