The annual miracles that come out of Zipp's engineering and manufacturing facility in Indianapolis continue to delight and inspire cyclists and triathletes. Certainly the success and results speak for themselves and as the cycling world changes, and the roads traveled vary, Zipp continually leaps ahead, delivering great riding, top performing aerodynamics wheels of many types. Now the concerted push towards disc brakes on road, gravel and cyclocross bikes has driven the development of a Tubeless ready, disc brake specific 303 Firecrest Carbon rim and complete rear wheel that is lighter and more aerodynamic than it's predecessor. Featuring Zipp's 177D disc brake hub and Sapim CX-Ray spokes, the rim design carries the rider faster, further afield, with greater control all around.

The 45mm deep 303's Tubeless disc brake only rim now has a wider 21mm internal measurement. When paired with a 700x25 tire, lower drag from the previous version. That effect is even more pronounced with a 28mm tire. Zipp carried through their proven disc-specific rim design featuring ABLC dimples, which extend all the way to the outer edge of the rim. The new wider rim then meets their Aero Balance requirement; Zipp's industry leading crosswind stability and low aerodynamic drag shape and design that defines all Firecrest wheels. This 303 Firecrest has a max width of 29.9mm, which means the inflated tire will work in greater concert with the rim to carry and hold the laminar air flow that not only increases speed, but improves overall wheel stability in varying wind conditions.

Developing a reliable, strong, and effective tubeless carbon rim configuration lead the engineers to approach all facets of the new 303 at the same time. This isn't an old design with a change of rim bed. Obviously the rim shape, width, and disc brake requirements allowed for a free hand in developing the tubeless aspect, and seeking ultimate reliability, tubeless seal, and tire hold at the low pressures afforded by today's tubeless ready tires, led the engineers to a rim bed made with internal ridges to proactively lock the tire’s bead in place. This provided the security desired, and still allows the user to opt for standard clincher tires and tubes, though with the advances and benefits in tubeless tires, it seems tube use will be limited strictly to emergency situations.

The 303 Clincher Tubeless Disc Brake Rear Wheel employs the 177 gram rear disc-specific hub, weighing in at 177 grams- which is an attention grabber, for sure. Zipp presets the bearing pre-load, so you don't need to worry about adjusting them. The bearings themselves have also been upgraded and have an improved seal that keeps them running clean and fast with the 17mm aluminum axle. While the newly designed quick releases and end caps are standard, the 135mm wide 177D rear hub is also compatible with thru-axle systems, both 12/135mm and 12/142mm. Simply change out to the desired end caps (included); a process that can now easily be done by hand. The freehub body set-up is also interchangeable, with Shimano, Campagnolo, and SRAM XDR options available.

The rear hub is laced to the new rim with a proprietary spacing and lacing system that starts at the hub. 24 Sapim CX-Ray lightly bladed, straight-pull steel spokes are used, along with Sapim's external Secure Lock nipples to ensure excellent tension for lateral stiffness and vertical compliance, but also to prevent hub wind-up or torque damage from the disc rotor. Lacing is 2x on both drive and non-drive sides, which makes truing and tensioning less variable.

Go further, faster, with greater stability, handling control, and braking than ever before with the Zipp 303 Clincher Tubeless Disc Brake Rear Wheel. At just 885 grams (1645g for the set), you can run the tubeless tire and pressure of your choice. Zipp engineers wheels that exceed expectations, giving you real incentive and equipment to exceed your own.