Zipp 858 NSW Carbon Clincher DB Rear Wheel 2019

Zipp 858 NSW Carbon Clincher DB Rear Wheel. Based on Zipp's high performance Zipp 454 NSW wheelset, the 858 NSW Carbon Clincher DB Rear Wheel benefits from an optimised and refined deep rim design and strong spoke pattern to deliver the highest level of road rolling quality around Deep rimmed and Exceptional Rolling Road Wheel. The specialised design of this stunning carbon road wheel sees it minimise air drag as its 77mm rim depth allows it to cut sharply through the air for the speediest travel. Easy to handle and superbly stable in the most taxing of headwinds, this 858 model utilises Sawtooth and Hexfix technology to give you complete and confident control in any condition. Supported by Sapim CX Ray J Bend spokes with Sapim Secure Lock nipples, shape and stability is assured on every run. Featuring a drag reducing Cognition Disc hub, enhanced rolling performance and disc brake compatibility, this superbly versatile, lightweight and responsively stiff back roller is the perfect fit for serious and leisurely road runners alike. Technologies Cognition. The 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 SawTooth. The namegivento the Zipp NSW variable depth 7782mm 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 Hyperfoil. This technological design refers to the individual nodes that are part of the Sawtooth rim design. Each of these structuresfeaturethe Hexfin ABLC dimples that stabilise handling in gusting and strong wind conditions by increasing wind vortex shedding. The dimples create a secondary vortex around the outer rim surface, which in turn heightens the wheel control and saves rider energy from being wasted HexfinAerodynamic Boundary Layer Control ABLC. The 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 rim's profile to further reduce high yaw drag and improve crosswind stability Features . Material Rim Carbon; Hub Aluminium Hub Model Cognition Disc; Disc Rotor Engagement Centre Lock Rim Width Outer 23 7mm; Internal 17mm Rim Type Carbon Clincher Rim Depth 7782mm Spokes Sapim CX Ray J Bend, 24H; Nipples Sapim Secure Lock; Lacing 2 cross Max Tyre Pressure 125psi Dimpled Surface ABLC, Hexfin Freehub 10, 11 Speed Weight 984g BuyZipp Wheels & Tyresfrom Chain Reaction Cycles, the World's Largest Online Bike Store.