58 millimeters of depth hits a particular sweet spot in the wheel market—deep enough to carry speed on flat roads, shallow enough to handle crosswinds without turning every gust into a wrestling match. The Zipp 404 Firecrest Tubeless Disc represents the current state of that balancing act, with an aerodynamic profile refined through computational fluid dynamics and wind tunnel testing. The Firecrest shape has evolved since its introduction, and this generation uses a wider rim bed and hookless bead design optimized specifically for tubeless tire mounting.

The 404 runs a 23mm internal width, which supports the wider tire preferences that have become standard in road cycling. A 28mm tire seats properly and inflates to a rounder profile, and the rim accommodates up to 50mm widths for riders pushing into light gravel territory. The hookless bead interface creates a more secure tire-to-rim seal when running tubeless setups, though it does require tires specifically rated for hookless compatibility—a consideration worth checking before mounting your preferred rubber.

Zipp pairs the carbon rim with their ZR1 hub platform, which uses a six-pawl driver system for engagement. The rear hub spaces for 12x142mm thru-axle standards, while the front takes 12x100mm—the dominant configuration across current disc brake road frames. Centerlock rotor mounting keeps things simple on the brake interface side.... Read More