Zipp 404 Firecrest Tubular Rear Wheel

When it comes to the light weight versus aerodynamics discussion, lateral rigidity often loses its place at the table. If your bike, if your wheels, have lateral flex, your effort is being wasted. Zipp focused on increasing lateral stiffness with this iteration of their 404 Firecrest Carbon Tubular.

The place to look is not at the rim, which has stayed the same, but at the spokes and the hubs. Zipp employs Sapim’s CX-Sprint spokes, which are aero, but stiffer than the CX-Ray. And they’re anchored to a new hub. The 77/177 hub set.

The new hubs are a marked improvement over the old. The pre-load adjustment of the 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 tensions. The hubs are lighter, too.

The resulting wheel is a bit heavier than the 303, a set weighs 1505g, but the shape is sufficiently aero to more than offset the difference on most rides and races. The wind is there only so long as you're moving, and if you're not moving, it isn't a bike ride.

Tame the wind, and you'll go faster. Firecrest's wide shape does a great job of not only improving aerodynamics when the wind is coming from twelve o'clock, but it is even better when the wind is coming from the side. The shape changes the airflow over the rim such that the wind pushes less hard against the rim and then thanks to tuning the shape, the focal point of the pressure has been pushed back a bit, to be in line with the steering axis, making it easier to steer the bike with less arm strength in a crosswind.

Firecrest also helps your tires roll faster. Tubulars have a set shape. The difference is that more of the tire casing is supported by the rim, which changes the way the tire responds to the pressure that bike and body place on it. More supported tire makes it easier to roll faster on less tire pressure. Zipp even contoured the rim bed to make it so the tire seam fits better. The rim bed shaping also makes it harder to roll a tire, thanks to more surface area for gluing.

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 404 will make you faster, no matter where you put it and whether it goes in front or in back. That written, pairing the 404 front with a 404 rear is common. Some folks will pair the 404 front with a deeper rear, like an 808 or a disc, taking advantage of the greater stability of the shallower front in crosswinds. Likewise, some folks will run a shallower front, like a 303, 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 he pads for greater pad 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.

The Zipp 404 Firecrest Carbon Tubular is all-around performance, as the wind is always there.

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