When people discuss the “quiver-killer” wheel, the Zipp 303 Firecrest Tubular could well be it. It’s light like a climbing wheel, aero like a time trial wheel, tough like a cyclocross wheel. Maybe this is why it has won cobbled classics, grand tours, and pro cyclocross races. And now, with Zipp’s new hub set at the center of the wheel, it rolls faster and is laterally stiffer as well.
The Firecrest shape is the first secret. Even though it sits between shallow and mid-depth rims at 45mm, the sides start at 25.14mm and widen to 28.5mm before taking a gentle arc into a blunt shape by the exposed spoke nipples. The nipples, btw, are more exposed to your eyes than they are to the wind, as when they’re on the trailing edge, the rim shape is such that the wind can’t find them. And, by having them on the outside, on the rare chance you need to true the wheels, nipple access doesn’t necessitate removing the tire.
A small note about the 303 shape. It’s the widest in the Zipp lineup. So wide that the rear wheel doesn’t fit in a few frames. Like the Specialized S-Works McLaren Venge and the 2012 Tarmac SL4. If you think your chainstays are particularly narrow, measure first.
But to improve the wheel, they had to change the spokes and hubs. They were looking to increase lateral stiffness, which is a plus in front for steering precision, and a plus in back for greater energy transferred to driving the bike forward. They moved on to Sapim CX-Sprint spokes, which are not only super aero, but pretty stiff for what looks to be a skinny blade. The 77/177 hub set is a new offering from Zipp and a real improvement.
The pre-load adjustment of the older 88/188 set is gone, simplifying things, as well as designing in lower lateral loading so the bearings roll more smoothly. The front flanges are taller, wider, and holds the spoke in a stronger position. The rear flanges are arranged in a star pattern, allowing for better bracing angles and yielding a strong cross-two pattern and higher spoke tensions. There’s a small, but real weight savings realized as well.
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 177 hub body allows you to install a SRAM XD-cassette body for super-wide range gearing.
The 303 will make you faster, no matter where you put it and whether it goes in front or in back. That written, matching the 303 front with a 303 rear is common. Some folks will pair the 303 front with a deeper rear, taking advantage of the greater stability of the shallower front in crosswinds. Likewise, some folks will run a shallower front with 404 rear, for the same idea, just in different applications.
The wheel is delivered with a Zipp quick release skewer and Zipp Platinum Pro brake pads. Both have been updated: the skewer for better ergonomics and aerodynamics, and the pads for greater surface area as well as cooling. Zipp strongly recommends use of their pads on their rims and warns against using carbon-specific pads on aluminum rims.
Also inluced is a valve extender, designed to work with a 37mm or longer valve stem.
The Zipp 303 Firecrest Tubular goes everywhere and wins every thing.