The 177 rear hub was engineered to replace the 188. This complete re-design optimizes the strength and stiffness of the machined aluminum body and offset flanges, allowing for greater tension with the 24 straight-pull Sapim CX-Sprint steel spokes and standard Sapim external nipples. A completely new bearing system was developed with higher grade steel sealed cartridge bearings with pre-adjusted pre-load. No need to adjust your hubs, ever. The 17mm oversized alloy axle system is stout and carries the incredible lateral loads achieved while sprinting, climbing out of the saddle, and on high speed, twisting descents. The 177 hub is also more user friendly when swapping out freehubs, or changing to a SRAM XD driver. There is no need to re-dish the wheel for such changes. Whatever the freehub, engagement is smooth, immediate and confident

The 58mm profile 404 Firecrest Carbon Clincher rim has a wide stance that improves overall feel, handling and ride quality, but is shaped more like the 202 than the 303, so it isn't quite as stout as the 303. It has a 26.53mm max rim width, with a 16.25mm internal clincher bead width. Firecrest rims have a near-constant width from brake track to spoke bed to improve aerodynamics and better control airflow. Zipp used Computational Fluid Dynamics software analysis to maximize the aerodynamics of the rim and dimpled ABLC surface while minimizing wind-produced torque, resulting in a rim design that is faster and better handling. The airflow is managed over the rim and passes more cleanly over the tire, which has less of a bulb-like shape than if the rim was narrower. The aerodynamics 404 Firecrest rim have been well proven in the wind tunnel and on the road, yet it is slippery in crosswinds at any yaw angle, and still very stable in heavy wind for excellent handling confidence, with substantially improved braking. The brake track tapers to 24.73mm at the center, to ensure compatibility with most road braking systems. The braking surface features the molded in-groove technology that ensures excellent stopping power in wet, dry, or hot conditions. Optimal performance is achieved with the supplied Zipp Tangente Platinum Pro Evo brake pads. The Silicon Carbide particles employed in brake track resin add extreme hardness, making the track impervious to incidental damage. This combination of tech is called Showstopper, and the results are impressive and effective.

Most road racing cyclists who run the 404 prefer the tubular version, but the labor and cost effectiveness of the Firecrest Carbon Clincher make the 404 an option for the serious enthusiast, and ideal for triathletes, many of whom don't have a garage full of wheels or much experience gluing tubulars. It also makes fixing a flat in an event easier, as a quick tube change in the unsupported triathlon world can get you back in the race. With the acceleration and speed of the 404, you might even make up the time as you burn off adrenaline. The superior handling characteristics of the 404 cannot be dismissed either. Again, not every triathlete has been riding deep section wheels for years. A few short rides on the 404 Firecrest will build confidence that the wheels will help the rider perform well in the wind. No other wheel company has Zipp's pedigree in engineering, experience, and event usage. You can trust the 404 Firecrest Clincher 177 Rear Wheel to provide the advantages every competitor desires. At 935 grams for the rear wheel (and 1690g for the set), speed, handling and pedigree come in a lightweight design with proven aerodynamics. Time to get rolling!