While the Zipp 303 NSW is an expansion of the NSW line. They needed to push farther, and the result is this 303 NSW Tubeless Carbon Clincher. Its faster and more flexible than the Firecrest, and the 303 itself is the depth and weight that appeals most to all-round riding, light enough for extended climbing, deep enough to speed on the flats.

Two things that are different right away are the new 19mm internal rim width and the tubeless channel. With the 19mm size, theyve optimized the rim for 25mm tires. The tubeless channel means you have the option to run either tubed or tubeless tires.

The 19mm width dictates a different rim shape than Firecrest. The depth remains at 45mm, the brake track at 26.4mm, but the widest spot is 26.5mm a bit of the way down the rim wall. This is to make sure 25mm tires are the most aero.

The rim comes with Zipps ABLC SawTooth dimple pattern. It improves aerodynamics in no wind (aka headwind) situations, but its greatest strength is reducing loads created by crosswinds. Youll have no concerns piloting these wheels on gusty days, even if youre small and riding aero bars. Its almost like a traditional box-section clincher. Overall, the wheel is faster in all wind conditions.

The brake track is Zipps ShowStopper textured braking surface. This is the 317 curved, vertical grooves on each side of the brake track that help move water off the surface and reduce stopping distances. In the wet or dry, this surface brakes as well as the best aluminum rims on the market.

Zipps Cognition hubs are deployed for the central movement. It utilizes a flangeless, radial front hub and a minimal, flanged rear hub that features two-cross spoking on both sides. The flanges are designed to be as light as possible without sacrificing strength. The rear hub utilizes Zipps Axial Clutch pawl mechanism, which reduces drag when coasting. The mechanism is on three cassette body choices: a SRAM 10/11-speed cassette body, a Campagnolo-compatible 10/11-speed body, and or a SRAM XDR driver body for wider-ranging cassette options, including 1x 10-42 cassettes. Spokes are the light and aero and strong Sapim CX-Ray.

Weight is 1500g for the set, 675g front, 825g rear.

The Zipp 303 NSW Tubeless Carbon Clincher wheels come with: Zipp Tangente quick releases, Zipp wheel bags, Zipp tubeless tape and valve factory-installed, valve core removal tool, Cognition Oil for rear hub, and cassette body spacer.