Not one track.
Since its rim is 58mm deep, it's easy to assume that Zipp's tubeless 404 Firecrest Carbon Disc Brake Road Wheel has a one track mind: aerodynamics, all the time, and nothing more. Zipp's history also supports that assumption. But now that its equipped with disc brakes and a tubeless-ready bead, the focus shifts slightly. The wheels stop better than ever, and the lower PSI of tubeless means they roll more efficiently, more comfortably, and with less risk of punctures.
Of course, the wheels are still aero-first (hence the insistence on "slightly" above), and ditching the rim brake track means that the aerodynamic benefits of Zipp's Aerodynamic Boundary Layer Control (ABLC) dimpling can extend all the way to the edge of the rim. While we can't guarantee anything, extending ABLC might logically be credited with reducing the additional drag caused by disc brakes—though, to be fair, we've seen estimates that it's as low as under 1g of additional drag, so the point may be moot.
Regardless of how far they extend, the ABLC dimples remain the foundation of the Zipp empire. The brand credits them with aerodynamic advantages at real-world yaw angles of 10 to 20 degrees, which compares favorably to many competitors whose minimum drag numbers manifest at yaw angles of five to 10 degrees—numbers that rarely occur outside of a wind tunnel. In non-tech terms, this means these wheels should outperform the competition in the conditions you'll actually encounter on the road.
While Zipp is mostly known for bestowing free speed through aerodynamics, the disc brakes do something that rim-brake carbon can only dream of: surpass alloy in terms of modulation, responsiveness, and overall stopping power. These qualities are a big deal for climbing wheels, as knowing you can depend on your brakes means you can carry more speed into corners, brake later, and not worry about locking your wheels up when an unexpected obstacle—an off-leash dog at a trailhead, the inevitable sudden motorist, rubble sloughed off of a canyon wall—materializes.
It also eliminates any fear of testing carbon brake tracks on rainy descents or during muddy cyclocross conditions. Don't get us wrong, we've had positive experiences with the second generation of Zipp's Showstopper brake track that features on the 202 NSW wheels; however, when it comes to virtually perfect stopping power, disc brakes are all but impossible to match. Adding disc brakes (and the requisite two-cross spoke lacing) does also add a few extra grams, but the increased stopping confidence more than makes up for the slight weight gain.
Despite the different tire-mounting format, the tubeless 404 Firecrest gets the same hub treatment as its clincher and tubular counterparts. The rims are laced to a 77 hub on the front and a 177 hub on the rear, both of which enjoy improved durability and stiffness compared to their predecessors. Featuring a new platform and graphics for 2016, these hubs boast increased bearing protection over their previous versions and are ready to roll without any pre-load adjustment. The rear hub is compatible with a separately sold XD driver body to allow for a wider cassette range of up to a 10-42t if needed, and driver bodies can be swapped out without having to re-dish the wheel. Each wheel includes an updated quick-release skewer with a widened handle that provides leverage when installing the wheel and clean lines as it sits close to the frame when closed.
Though it may be best suited as a road wheel, each 404 Firecrest Disc Brake model ships with thru-axle conversion end caps for 12 or 15 x 100mm up front and 12 x 142mm in the back. The wheels also include standard quick-release skewers, so regardless of your gravel, 'cross, or road axle standards, you should be covered.
- An aerodynamic wheel that stops as fast as it goes
- Deep, versatile profile is ready for racing and long solo rides
- Disc brakes add confidence to braking in all conditions
- Tubeless construction increases comfort and supple feel
- Better flat prevention and easier recovery for when you do puncture
- Includes quick-release skewers with fork thru-axle adapters
- Zipp's aerodynamic empire is built on a foundation of dimply speed