Originally Posted by
HillRider
Not sure about the headset but use Reynold's brake nut. The Shimano recessed nut is sized for a typical metal fork crown thichness and carbon forks are often much thicker so the longer nut is required. My Kestrel EMS Pro fork came with a longer nut and instructions that it had to be used. They were right.
My Easton EC90SLX fork didn't come with a special nut but the rear hole in the fork crown is recessed much more than usual so the shorter standard nut works fine.
Thanks, HillRider. I was kind of guessing that that was the reasoning for the included nut, but Reynolds didn't specify in their instruction manual or on their web site's FAQs. It's nice to get some confirmation.