I'd like to upgrade to a carbon fork on my steel Giant Kronos. Can I go from the "Quill" wedge style steer tube to the newer head set version? What's involved?
Almost all carbon forks have threadless steerers these days so you will need a new headset, a new stem and some spacers to adjust the stem height before cutting the steerer to length. If the steerer is also carbon, you will need a compression plug to set the headset adjustment as a star nut cannot (read; MUST not) be used with a carbon steerer.
Are your current stem and steerer 1"? If so, you will have a more limited choice of forks as most are 1-1/8" these days but 1" is available.
Check out Park Tool's web site for info on both headset and fork installation.