Zipp 454 NSW Carbon Tubular Road Wheels - XDR

. Featuring a selection of Zipp's latest technological innovations, this 454 NSW all carbon tubular wheelset offers exceptional race day advantages. From the undulating 5358mm deep SawTooth enhanced rim, which minimises aero drag and side force from all wind yaw angles, to the crosswind proof Hyperfoil rim texturing, these wheels offer unparalleled speed, aerodynamics and stability. Advanced Hubset Design. With its built in Axial Clutch technology, the Cognition hubset featured in this wheelset interacts with your freehub's ratcheting mechanism to cut mechanical drag in half, allowing for excellent control and efficiency whether you're pedalling or coasting Features MaterialRim Carbon; Hub Aluminium Hub ModelCognition Rim ProfileDepth 5358mm Rim TypeCarbon Tubular SpokesSapim CX Ray J Bend, 18H, 2 cross Max Tyre Pressure125psi Dimpled SurfaceABLC, Hexfin Freehub Compatibility SRAM XDR Weight640g front, 795g rearTechnology CognitionThe ultimate in Zipp hub technology. Every time a conventional hub set starts to coast, friction within the freehub ratchet mechanism works like a drum brake to slow the rider down. The drag between hub shell and driver body during coasting is considered as efficiency loss, especially for road wheels. High drag also can significantly contribute to chain dropping issues. The drag torque drives the cassette clockwise so the chain gets loose on the load side. The solution The rear Cognition hub with AxialClutch technology reduces drag by disengaging the ratchet mechanism when coasting. It then uses magnets to re engage once the rider starts pedalling. SawToothThe name given to the Zipp NSW variable depth 5358mm rim profile. This design is the result of rigorous wind tunnel and real world testing. The rim shape takes natures elegant design solutions and combines their precise engineering finesse to deliver a wheel that performs like nothing else before. Hexfin Aerodynamic Boundary Layer Control ABLCThe Sawtooth dimple design consists of 12 nodes that are specifically clocked to start aerodynamic shearing at a rate of 50hz at a rider speed of 20mph. Sawtooth accomplishes this by inducing small sheet vortices that shed at a low magnitude, but at a higher natural frequency, thus decreasing the laminar bubble effect on the aerodynamically shielded side of the rims profile to further reduce high yaw drag and improve crosswind stability. ImPressZipps ImPress graphics technology prints graphics directly on the wheel, which allows the dimples to do what they were designed to achieve, to control vortex shedding and the rate at which air sheds off the wheel. Managing this is crucial to stability. ImPress graphics also give NSW a distinctive stealthy look BuyZipp Wheels & Tyresfrom Chain Reaction Cycles, the World's Largest Online Bike Store.