Zipp 858 NSW Carbon Wheel - Tubeless for Sale, Reviews, Deals and Guides

Zipp, whose 808 NSW Carbon Tubeless Road Wheelset has returned from its latest victory lap with a slew of changes including improved aerodynamics, a re-engineered brake track, and a ground-up revision of the lay-up schedule. The results are a faster, lighter, more structurally sound wheel that better accommodates the new racing standard of 25mm tires and is more responsive when you grab the brakes. In addition to advancements of the rim, Zipp pairs the 808 NSW with the Cognition hubs for an entirely aero-focused design. The hub owes its sleek look to Zipp's Axial Clutch freewheel design, which features two Metal Injection Molding (MIM) ratcheting rings: one mated to the freehub body and one mated to the hub body. The two rings are machined like a ratchet, so they ramp off of each other while freewheeling but engage each other during pedal input.

Zipp's signature Aerodynamic Boundary Layer Control (ABLC) dimpling returns with a new designation. It's called SawTooth Technology, and it consists of ABLC dimples applied in a single pattern repeated in 12 discrete swathes (or "nodes") across the rim's surface, looking much like the strokes of a paint brush. Zipp's description of SawTooth's effect is a bit erudite, with the company claiming a 34% reduction in side wind forces compared to the previous ABLC pattern. It achieves these gains by "reducing the laminar bubble effect on the aerodynamically shielded side of the rim's profile." Translated into saddle speak, that means while rolling at 20mph and above, the rim's dimpling is designed to dispel the negative, drag-inducing force on the rim's non-wind side.

Though Zipp was one of the shape's early adopters, the industry is now replete with rounded, bullet-shaped rim designs that aim to lessen destabilizing drag from cross wind forces; however, if Zipp's numbers are any indication, the SawTooth nodes take that reduction to a whole new level by better controlling cross winds as they detach from the rim's opposite face. While deep rims will always be more vulnerable to lateral forces than shallow box clinchers, the Firecrest DSW's rim shape and SawTooth Technology contribute to a ride that requires less correction in windy conditions, and the corrections themselves are more subtle and intuitive than with yesterday's NACA profiles.

It's only appropriate that we end the way every good ride does: with the brakes. The rims are equipped with an updated version of Zipp's Showstopper brake tracks. Showstopper enjoyed an impressive debut on the recently released Firestrike line (which was limited to the 404 platform), but it's already been improved for the 808 NSW. It's still imbued with the same silicon carbide particles, but the direction-specific grooves have increased in number and feature an altered depth. The original Showstopper netted some pretty impressive stopping across all conditions, and Zipp assures us that the new design is even better. The upshot is you can hold speed longer while approaching a corner, braking later and gaining tiny increments of time with each bend or switchback.