Interloc Racing Design Double Roller Drive Headset 1" Threaded - SilverRoller bearings for both the upper and lower cups for improved headset performance Roller bearings offer 3 distinct areas of advantage over traditional round bearing headsets: steering dampening, greater strength, and greater durability Increased bearing contact acts as a damper absorbing high and low speed vibrations Roller bearings have a much greater contact area offering increased strength Load is spread over a great area with roller bearing,