In the velodrome, riders talk of improvements in fractions of a second and millimeters of track, with races being won or lost by the width of a tire. In an arena where small advantages matter, the Zipp 404 Firecrest Tubular Track Wheel brings a perfect balance of aerodynamic speed and snappy acceleration to fast forward your track racing ambitions. The 404 is one of the more ambitious rim designs in the Zipp line. Designed to bridge the gap between pure aero speed and whip fast spin up, the 404 Firecrest features an aerodynamic 58mm rim depth and a maximum width of 26. 53mm, creating a stable structure that provides greater vertical and lateral compliance for a smooth, controlled ride. This design also increases lateral stiffness for snappy sprints and unwavering cornering. Zipp uses an updated version of its signature Aerodynamic Boundary Layer Control ABLC dimpling with strategically placed and sized dimples across the rim surface to reduce drag and smooth airflow, allowing the wheel to eliminate the pockets of dead air in the rims' wake that are responsible for wheel suck. At the center, Zipp incorporates its track specific 333 hubset, built to withstand the rigors of track racing. 7075 aluminum hubshells wrap around stainless steel axles to create a lightweight, strong hubset that winds up fast. The rear hub features an asymmetrical flange to achieve equal tension in both the drive side and non drive side spokes, which effectively eliminates torsional deflection in the hub under load. This means instant acceleration and perfect tracking through every turn, even when you're dropping maximum sprint watts into the pedals. The front hub boasts a 54mm spoke hole circle diameter and 15mm axle to keep the front wheel solid and responsive. For ease of maintenance, the Zipp 404 Firecrest Tubular Track Wheel is easily removable from the bike with a 6mm Allen wrench, and the axle locknuts are compatible with standard open end wrenches. Each wheel comes accompanied ...