Zipp

404 Firecrest Carbon Road Wheel - Tubular - 2013

You might need a microscope to understand the intricacies of the 404 Tubular, but you certainly don't need one to grasp the magnitude of its records. From L'Alp d'Huez to Kona, it's nearly impossible to find another wheel with such a storied career. However, the best just got better with the 404's adaptation of Zipp's Firecrest technology. Now, with the 404 Firecrest Tubular, stability has been increased, weight has been dropped dramatically, and aerodynamics are in a different universe. The future is here.

The 404 is one Zipp's most ambitious rim shapes. It maintains a rim depth of 58.0mm and a maximum width of 26.53mm in the front and 27.07mm in the rear. The Zipp 88/188 hubs' bearing stance has been widened by 7.5mm, and the rim's body shape has been canted out by two percent. Zipp found that the design creates a more stable structure, and offers greater vertical and lateral compliance with increased control, comfort, and rigidity. While the 404 benefits from these welcomed additions, to achieve the Zipp-standard of strength and rigidity, the 404 utilizes uni-directional fibers to handle the tensile and comprehensive loading within the rim, and woven fibers in the spoke-hole areas. A woven silica-ceramic fabric and a woven carbon fabric encapsulate the braking and tire-mounting surfaces. The combination of fiber patterns creates a high stiffness-to-weight ratio without stacking up the grams.

A number of Zipp technologies went into making the 404 Firecrest one of the most versatile wheels in the Zipp arsenal. First, the Multi-Material Co-Molding process permanently fuses a sub-200-gram aluminum hoop to a dimpled carbon structure that acts as a leaf spring for road vibration and impact. Spokes laced directly to the carbon body give you the benefit of a carbon feel and aluminum braking. Next, visco-elastic material is inserted between carbon laminate in the rim to reduce road vibration by ten percent. Lastly, the dimples of the Aerodynamic Boundary Layer Control (ABLC) on the curved rim section work to create a slight turbulence directly above the rim surface. This creates an artificial boundary layer that forces the laminar boundary layer towards the forward part of the rim to become turbulent. This process enables airflow to remain attached over more of the rim for a longer period of time, providing a lower level of integrated drag. The drag that ABLC creates is called skin friction drag; although it's greatly increased, pressure drag (which is ten times higher than skin friction) is decreased to make the 404 wheels faster than the competition in a wide range of conditions, not just the wind tunnel. While most wheels only enjoy minimum drag at rarely occurring yaw angles of five and ten degrees, the 404 experiences it at the real-world conditions of 10 to 20 degrees.

The Zipp 404 Firecrest Tubular front wheel features a radial-laced 16 spoke Zipp 88 Front Hub, and the rear wheel uses a drive-side radial, non-drive cross-laced 20 spoke Zipp188 rear hub. Every wheel is hand-built in the USA, and the rear wheel is available in two freehub configurations to fit either Campagnolo or Shimano/SRAM cassettes. Each wheel configuration is available with the label colors Black or White. Please note that Zipp's maximum recommended rider weight is 250lbs, and that the Shimano freehub configuration is compatible with Shimano Dura-Ace 9000 cassettes.