Posted August 30, 2021 at 5:11 pm by Simon Andrea


The Zipp 303 Firecrest Carbon Clincher’s 45mm rim depth was once considered deep. Now, thanks to better understanding both carbon fiber and the wind, the 303 is a shallowish-mid-depth wheel that is fast in all conditions. It’s light enough for climbing, deep enough to make a big difference on the flats, and with the further-improved shaping, it’s even less visible to strong crosswinds.

This is a serious refinement of the Firecrest shape. It’s blunt on the spoke side, with only slightly-curved walls on the way to the brake track. The width at the brake track is 26.4mm, which is also as wide as the rim gets. The inner width of the rim is 17mm and the outer walls of the rim curve slightly from the spoke bed to the sidewalls, which means that the best aero tire choice leans toward 25mm tires. In addition to refining the shaping, Zipp has trickled down the ABLC  dimple pattern from their NSW wheels. It improves aerodynamics some in “no wind” situations, but it has been proven to be much better at reducing loads created by crosswinds. You’ll have no concerns piloting these wheels on gusty days, even if you’re small and riding aero bars.

Another great trickle-down improvement is the addition of ShowStopper textured braking surface. This is the 317  vertical grooves on each side on the brake track that help move water off the surface and reduce stopping distances. In the wet or dry, this brakes as well as the best aluminum rims on the market.

They also added their 77/177 hubset to the rims. The 18/24 hubs feature straight-pull Sapim CX-Sprint spokes, with the front radial and the rear two-cross. The rear hub has cassette body options: 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.

Amazingly, even with all the new features, they were able to reduce the wheelset weight by 145g compared to the previous version. The wheels weigh 645g front, 835g rear.

The Zipp 303 Firecrest Carbon Clincher wheels come with Zipp’s Tangente Platinum Evo brake pads, rim strips, Zipp valve extenders, and quick releases. The quick releases have a wide handle to reduce pressure in your palm and are designed to sit nearly flush with the frame when closed.

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