The rim that was strong enough to survive Paris-Roubaix and fast enough to win solo is a great foundation for a wheel designed to conquer everything. That’s the key to understanding the Zipp 303 Firecrest Tubular Disc-Brake wheel. The rim itself has also won hilly classics and grand tours. And the disc-brake version has also proven itself in the cyclocross pasture under riders like multi-time national champs Jeremy Powers, Ryan Trebon, and Tim Johnson.
It’s the ‘crossers who first took this wheel into competition. They pioneered the use of disc braking at the higher level of ‘cross, and even took their Zipp 303 disc tubulars to the World Championships.
The wheels have been proven strong. And as riders have to carry their bikes in CX, these wheels have been proven light. But what’s less apparent from the experience is that they’re great all-around aero wheels. The rims have won in all conditions on all roads already. The rims haven’t changed. Even with the cyclocross pedigree, these wheels are also road wheels. And if you’re looking to add performance to your disc-brake equipped road bike these are light and aero and strong.
The 303 rim was a natural for disc-brake applications. The rim hits the sweet spot of strong, light, and aero. Wheelset weight is 1400g, 640g for the front, 860g for the rear. Tubular rims are stronger and lighter than clinchers, and the ability of the tire to stick to the rim is great in CX, but not everyone has the time or desire to deal with sew-ups. For those folks, there’s also a clincher version available.
Zipp keeps their rims the same, whether it’s disc-specific or rim brake-specific. They believe that if they cut weight from the rim, they’d be weakening the wheel in terms of impact resistance and compromising lateral rigidity.
The hubs are where most of the differences occur. Zipp employs their 77/177D hub set, which was purpose-built for disc braking. There are 24 Sapim CX-Ray spokes, both front and rear. A cross pattern is necessary in front to counter the forces of braking. The flanges are slightly taller to work around the six-hole rotor mounts and the 17mm axle. While you can see that the spokes have a two-cross pattern, it actually possesses the lateral stiffness of a three-cross thanks to the size of the flanges and the orientation of the spokes. The benefits of the design are more aero and shorter spokes.
While finding a disc-brake equipped road frame with narrow chain stays is unlikely, we’re duty-bound to inform you that on some rim brake-equipped road bikes, the Zipp 303 rim is too wide to fit between the stays. Measure first.
For rear wheels, Zipp offers both a Campagnolo-compatible, and Shimano/SRAM-compatible cassette body. The latter comes with a spacer for 8/9/10-speed cassettes. In both cases, the 177D hub body allows you to install a SRAM XD-cassette body for super-wide range gearing.
The wheel comes with quick release, endcaps to convert the hub for thru-axle use (endcaps are hand swappable), and valve extender.
The Zipp 303 Carbon Tubular Disc-Brake came into the world on cyclocross bikes; it has found a second, equally impressive, home affixed to road bikes and gravel grinders.