Zipp 404 S Carbon Rear Road Bicycle Wheel

The Zipp 404 S Carbon Rear Wheel is a 50mm-deep carbon road wheel built to bring race-level aerodynamics down to a more attainable price point. Sold here as the rear wheel only, it takes over from the 303 S as the road-focused entry in Zipp's S Collection, using a mid-depth rim profile borrowed from the WorldTour-proven Firecrest design — deep enough for a real aero benefit, shallow enough to stay stable when the wind picks up.

Zipp positions the 404 S as an upgrade over the 303 S in every category that matters: aerodynamics, hub performance, aesthetics, and price. The rim is a hookless, Tubeless Straight Side (TSS) design at 50mm deep with a 23mm inner width, meaning it's engineered around tubeless tires from the ground up rather than treating them as an add-on.

Who It's For

• Road cyclists upgrading from alloy or entry-level carbon wheels who want a measurable aero gain

• Racers and fast group-ride riders who want Firecrest-derived aero performance without NSW-level pricing

• Riders already on tubeless tires, or ready to switch — this rim is not compatible with tubed setups

• Not the choice for riders who need a wheel for gravel or mixed-surface riding; that role belongs to Zipp's 303 XPLR S

What to Look For

• Match your drivetrain: this wheel is offered with either a Shimano HG or SRAM XDR freehub body

• Confirm your tires are tubeless-ready and rated for hookless rims before mounting

• Check frame compatibility: built for 12mm thru x 142mm rear spacing with a Center-Lock disc rotor mount

Key Features

The hookless TSS carbon rim is the core of this wheel's performance case. At 50mm deep and 23mm internal width, its Firecrest-derived shape is built for smooth airflow while holding a steady line in crosswinds, and it's tubeless-only by design — there's no tubed fallback here.

The Zipp 176 hub runs stainless steel cartridge bearings with 36 points of engagement, so power gets to the road quickly after coasting or a shift. Spoke-wise, the rear wheel uses a 20-hole, 2-cross pattern with Sapim CX-Sprint spokes, a lacing built for stiffness under load rather than outright compliance.

At 1,585 grams, it's light for a 50mm-deep wheel, and the UD carbon fiber construction with adhesive decals keeps the black/white finish clean without the added weight of paint.

Rider Intent Summary

• Biggest strength: A 50mm Firecrest-derived aero profile at 1,585 grams — Zipp cites roughly a 2-watt saving over the 303 S at this depth
• Tradeoff: Tubeless-only compatibility rules it out for riders committed to tubed tires, and hookless rims demand tubeless-ready, hookless-rated tires
• What makes it different: It's the road-specific wheel in the S Collection, distinct from the gravel-oriented 303 XPLR S and XC-focused 1ZERO HITOP S

Victory's Take

At Victory Bicycle Studio, we point riders to the 404 S when they want a documented aero and hub upgrade over the 303 S at a mid-tier price, as long as they're running — or willing to run — tubeless tires.