The new Zipp 404 S wheelset brings carbon tubeless aerodynamic Zipp wheels to a previously unheard-of price point. The 50mm-deep, 1,585g wheels are priced at 985 / $1,300 / 1,100. They come with Zipps proven 76/176 hubset and Sapim CX Sprint spokes, backed by Zipps no quibble lifetime warranty and crash replacement policy. While the outgoing 303 S wheels hit the same price point, Zipp says the 404 S with its improvements in aerodynamics is its first high-performance specialist aero wheelset at this price point. Why make the 404 S? The 404 S brings Zipp's carbon aero knowhow to a lower price point. Ashley/Jared gruber With the rise of competitor Asian wheel brands and a myriad of new wheel builders emerging, established specialists such as Zipp, Mavic and ENVE have faced stiff competition in recent years. This led to Zipp not only reducing the prices of its premium Firecrest models, but also the arrival of the S line of affordable wheels. The 404 S is the latest model to join the S range. The new design borrows the shape from the Firecrest wheels, although the rim depth has been reduced from 58mm to 50mm. The rim follows Zipps established TSS (tubeless straight side) hookless design with a 23mm internal width. Like the 404 Firecrest, it's optimised for 28-30mm tyres. Zipp says the new shape saves 2 watts over the 303 S. Detail-heavy testing The Zipp 404 S compared to similar-depth all-rounder wheelsets. Zipp Those who are familiar with the 404 Firecrest will know it's Zipps fastest road wheel, with a rim section thats 58mm deep. The 404 S, however, is aimed at bridging the gap between the pro-level 404 Firecrest and the all-rounder 303 S at 40mm. Nathan Schickel, Zipps road wheel product manager, explains the reason for the 50mm depth. "It still gives a real aero advantage, but is more user friendly in all conditions than a specialist aero option like the 404 Firecrest, or similarly deep wheels of Zipps competition," he says. Zipp has benchmarked the 404 S in a new way, using wind-tunnel data, real-world data and CFD (Computational fluid dynamics). The real-world data and CFD involve data collection from riding in different wind conditions and at various yaw angles. The data collation also included historical meteorological data to better understand the wheels' performance. The graph produced from this testing balances the aero and yaw data into a single 'weighted aero drag (watts) number on the vertical axis, and on the horizontal axis is the price (in $). By plotting the aero data against price, Zipp hopes to give riders a better understanding of what you can expect to gain for your outlay. Zipp 404 S details The 404 S rim is 50mm deep with a hookless 23mm internal width. Zipp The full-carbon rim has an internal width of 23mm and uses Zipps straight-sided hookless rim design. It's fitted with Sapims CX Sprint steel spokes cheaper, marginally heavier spokes than the CX Rays found on Zipps premium wheels. The front features 20 spokes and the rear 24. Zipp hasn't made the switch to carbon spokes as many competing brands have. Schickel explains the brand has been testing carbon spokes for two years, although it remains unconvinced by carbon's longevity and toughness when it comes to wheels. By using steel spokes, Zipp has been able to give the 404 S a generous maximum weight limit of 235lb/115kg. The wheels are also backed by Zipps unconditional lifetime warranty and crash replacement policy the same cover afforded to the brand's premium models, which retail for more than twice the price of the 404 S. The 176 rear hub has a 3-pawl, 36-point engagement freehub. Zipp The wheels are completed by Zipps 176/76 hubset. These hubs have been in Zipps range for more than a decade. Schickel says the reason for choosing this paring is theyre dependable, durable and with improved bearing seals. Consisting of contact seals on the outside, with non-contact on the inside, theyre well protected from the elements, yet have reduced system drag. The 176 rear hub uses a 3-pawl driver body with 36 points of engagement for quick engagement. The rear wheel comes with either SRAM XDR or HG11 freehubs. The 404 S effectively replaces the 303 S and has already been seen on new bike specifications most notably on the updated SRAM Force AXS equipped Canyon Aeroad CF SLX 8. Ventum and Megamo have also announced bikes equipped with the 404 S. The Zipp 404 S is available with bold white or understated dark grey graphics. Ashley/Jared Gruber The Zipp S range of wheels now has the 404 S for the road, and the 303 S XPLR for gravel and all-road, with the 1Zero Hitop S covering XC mountain biking. Zipp 404 S pricing Zipp 404 S front wheel: $630 / 475 / 530 Zipp 404 S rear wheel (HG or XDR): $670 / 510 / 570 Zipp 404 S pair: $1,300 / 985 / 1,100