• There is more to our carbon headsets than their exceptional good looks. From top to bottom, Box One™ Carbon Headsets have been designed to perform. Each unit features a custom CNC-machined alloy top cap in the shape of the Box logo with cut-outs to reduce weight. At the center of the top cap is an anodized aluminum bolt that threads into a gold anodized aluminum expander plug. This expander eliminates the need for a star nut and works with all 1 1/8-inch steerer tubes—even carbon fiber steerer tubes. The top bearing cover is crafted from carbon fiber, which not only adds style but helps to shave weight. At the heart of the headset are two super-smooth, titanium-nitride coated, sealed, 45×45 bearings. The titanium coating results in a low friction coefficient, increased corrosion resistance and smoother rolling bearings. A split crown race makes installation and removal from forks super easy. Box 1.5-inch headsets are designed solely for tapered frames and forks, but also include an adapter which allows you to run a fork with a straight 1 1/8-inch steerer tube.