Zipp 858 NSW Carbon Disc Brake Tubeless Front Wheel

The Zipp 858 NSW Carbon Disc Brake Tubeless Front Wheel sits at the top of Zipp's road wheel lineup — the deepest carbon disc rim they produce at 85mm, built specifically for riders who prioritize maximum aerodynamic speed above everything else. Zipp positions the 858 NSW as the wheel of choice for triathlon, time trialing, and road applications where raw velocity is the primary objective. It is not a versatile all-rounder; it is a purpose-built speed tool. At 719 grams, the front wheel is also significantly lighter than the previous 858 NSW generation — Zipp removed more than 243 grams from the overall wheelset during the redesign. That reduction shows up in acceleration and sustained-effort efficiency, and it means the 858 NSW delivers the aerodynamic return of an 85mm rim at a weight typically associated with rims that are 20mm shallower.

The central technology in the 858 NSW is Zipp's Sawtooth rim profile — a patented variable-depth design developed through wind tunnel testing, CFD modeling, and real-world validation. The rim doesn't maintain a constant 85mm depth; it undulates between 82mm and 85mm, with a series of raised Hyperfoil nodes spaced along the inner rim diameter. Each of these nodes is paired with HexFin ABLC dimples — hexagonally shaped depressions whose angular geometry increases boundary layer mixing at the rim surface, helping keep airflow attached for reduced drag and improved crosswind stability. The dimples are arranged in fin-shaped clusters of variable sizes that work with each Hyperfoil to manage vortex shedding. The result is what Zipp calls AeroBalance: the Sawtooth profile simultaneously reduces both aerodynamic drag and side force across all wind yaw angles. That's the key distinction — most deep rims trade crosswind handling for aero efficiency, generating rim-induced steering torque that the rider has to counteract. The 858 NSW is engineered to reduce both variables at once.

Zipp's TSE (Total System Efficiency) framework governs how every element of the 858 NSW was designed. The approach addresses the four barriers to cycling speed — wind resistance, rolling resistance, gravity (weight and structural durability), and vibration losses — rather than optimizing a single metric. The Sawtooth profile handles wind. The hookless tubeless rim addresses rolling resistance and weight together: eliminating the bead hook creates a more precise tire interface that reduces rolling resistance, and the hookless construction itself removes material from the rim. The Carbon Internal Reinforcement (CiR) layup achieves the same structural integrity as the previous generation at 10% less weight. Zipp's data identifies 28mm as the optimal tire width for the 858 NSW — wide enough to run lower pressures for decreased rolling resistance without generating excess frontal area. Minimum tire width is 25mm, and maximum tire pressure is 73psi/5.0 bar.

The Cognition V2 hub at the center of the 858 NSW is built around Zipp's Axial Clutch V2 mechanism. Conventional hub designs create drag through the engagement mechanism even when the rider isn't pedaling — the clutch system is in constant light contact with the driver body during coasting. The Axial Clutch V2 separates the engagement mechanism from the bearing load path when not under pedaling load, reducing friction during descents and transitions where maintaining speed without effort matters most. The result is a hub that rolls efficiently pedaling or coasting, with quicker engagement when power is reapplied. The ImPress graphics process, which prints designs directly onto the carbon fiber rather than applying decals, is directly related to aerodynamic performance — a smooth surface at each HexFin dimple location allows the dimples to manage vortex shedding as designed, without a decal layer interrupting their geometry.

The front wheel uses a 23mm internal width rim with a maximum outside width of 27mm. Hub spacing is 12mm thru-axle with end caps included; the brake interface is Center Lock disc with lockring included. The hookless design is optimized for tubeless tires — Zipp publishes a compatibility guide that should be confirmed before tire selection, as not every tubeless-ready tire is approved for hookless bead seats. Running a tubeless-ready tire with a tube is possible as a backup option. The 858 NSW is sold as an individual wheel, allowing riders to pair it with the 858 NSW rear or mix wheel depths for specific conditions or race formats. Zipp covers the 858 NSW with a lifetime warranty against product defects during riding use.