I'm installing an FSA Orbit CF hs in a '08 Roubaix Pro frame and fork - having great difficulty getting the compression ring inside the bearing assembly. Is there a tool for this or any special technique used?
Yes. I have the small end of compression ring facing down - I know it needs a tight fit so everything's nice & tight, but I've tried everything including a hoseclamp (suggested by lbs) to get the ring small enough to slide in - the steerer tube only allows it to close only so much.
the steerer tube only allows it to close only so much
The compression ring should be on the top part of the headtube. I just slid the compression as far down as I could by spacing the gap larger (screwdriver tip), and pushing it down by hand first, avoid scratching the steerer. Once I put the cap and stem over it, used the Fork compression plug to push down the spacers and the stem. I didn't get any directions, but that's what worked for me.