Zipp 404 Firecrest Carbon Tubeless CL Disc Brake Rear Wheel The 404 Firecrest Carbon Tubeless CL Disc Brake Rear Wheel has been conceived via Zipp's "Total System Efficiency" design process that equally balances aerodynamics, weight, rolling resistance and comfort. Using these prerequisites, this wheel's performance has been tuned to heighten performance in road races or efforts against the clock. A hookless tyre interface allows the full carbon construction of the rim to be realised with superior resin distribution for lower weight and increased lateral stiffness. The hookless format includes a broad, 23mm internal rim width that aids tubeless-ready tyres in performing with lower rolling resistance at bump-absorbing lower inflation pressures. This wider internal configuration also smooths the tyre-to-rim junction, working in tandem with the 58mm deep rim profile to markedly lower aerodynamic drag. The refined rim profile increases stability in blustery conditions, while the ABLC surface dimples create a boundary layer of air to further decrease wind resistance. The Zipp ZR1 DB hub uses smooth spinning bearings and has a 66-point engagement freehub to quicken its response to pedalling input. Sapim spokes connect the build, promoting efficiency and durability via their two-cross lacing pattern. Includes 12mm hub end caps Center Lock lock ring Highlights The versatile, good-value 404 Firecrest is an exceptional pick for road races or efforts against the clock Conceived via Zipp’s “Total System Efficiency” (TSE) design concept that equally factors aerodynamics, weight, rolling resistance and vibration losses (comfort) A special tool that measures aerodynamic drag, rolling resistance, wind speed and wind yaw angle while on the road, was key in the development of these wheels  The TSE holistic design approach equals more speed in real-world riding conditions rather than just wind tunnels The rims use a high grade of carbon fibre to lower weight, increase strength and improve lateral stiffness The hookless internal rim design is for tubeless-ready tyres only, promotes a more aerodynamic tyre to rim interface and lowers weight via more even resin distribution A 23mm internal rim width works optimally with wider tubeless-ready tyres, lowering rolling resistance and improving comfort Optimised tyre bed for easy tyre installation The 58mm deep, refined rim shape optimises aerodynamic efficiency and crosswind stability An intricate rim surface ABLC dimple pattern further lowers drag The ZR1 DB hub has a better seal design for improved durability and offers a quicker pedalling response thanks to the 66-point engagement freehub 24 Sapim spokes are laced in an efficient and durable two-cross lacing pattern Lifetime Warranty