External Headset problem

on-yer-bike Posts: 2,974
edited April 2014 in Workshop
Installed the cups into the carbon frame, fitted the head race and its flat on the fork shoulder. The top cap isnt rubbing on the top cup and the compression washer is in place. When I go to load the bearings the whole assembly starts binding with just half a turn. So basically I cant load the bearings without the whole thing locking up. Its a Ritchey WRS headset that Ive used before without issues on another frame. Im wondering if there is a washer missing but cant find one. Any ideas?