The R45 front hub is lighter and more aerodynamic than most built-to-last hubs on the market. We use a narrow hub body and low flanges to make the R45 a rock solid starting point for any fast wheel build.Our bearings, both steel and ceramic, have heat-treated, surgical grade steel races that are machined simultaneously to ensure perfect matching. The quality and speed of our bearings is what you will feel (and hear) on every ride. As Chris King bearing tracks burnish they get actually get faster. A little bit of regular love (i.e. service) will keep this hub rolling for years upon years of demanding use.Features:- Engineered, manufactured, and assembled in Portland, Oregon USA- Legendary made-in-house bearings- Easily serviceable with a 2.5mm hex and pick or pen knife- Completely re-buildable with our R45 Hub Service Tool- Ceramic bearing upgrade availableSpecifications:- Axle Width: 100mm- Flange Diameter DS & NDS: 39.8mm- Center to Flange DS: 34.8mm- Center to Flange NDS: 34.8mm