A whale of a ride.
If you'll forgive us the pun, we think it's safe to say Zipp made a splash with the release of the 454 wheelset. After all, the brand used biomimicry and looked to the sea when seeking new aerodynamic inspiration for this wheelset. The 454 NSW Carbon Clincher Disc Brake Road Wheels features a unique, alternating rim shape inspired by the tubercles found on the edges of humpback whales' fins for a rim profile that maximizes aerodynamic benefits at all yaw angles and increases crosswind stability when those angles get steep.
The most immediately obvious difference between the 454 and any other wheel is in the rim shape, whose depth varies between 58mm at its deepest point and 53mm at its shallowest in a series of wavy swells Zipp refers to as Hyperfoils. The overall design is known as SawTooth, which takes on a shape not dissimilar to the ABLC SawTooth dimple patterning found on the 404 NSW. These bumps, designated as Hyperfoils, are meant to mimic the nodes or tubercles found on the fins of humpback whales that manage water resistance and contribute to the massive animals' ability to swiftly maneuver despite their size. Compared to standard, consistent depth rims, Zipp claims that wind tunnel testing shows that this SawTooth design significantly reduces both side force and aerodynamic drag, which in combination should translate to more confident handling when riding on exposed roads in variable winds and an easier time pushing the pedals any given speed compared to even the 404 NSW.
The 454 NSW also marks a departure from Zipp's signature dimpling, upgrading the ABLC design to HexFin ABLC. The HexFin ABLC dimples take inspiration from their round predecessors' claimed ability to better manage the boundary layer of air against the rim, but Zipp tells us that the updated, hexagonal shape enjoys yet more of the stable aerodynamic benefits associated with the now-traditional round dimples. Further departing from the all-over dimpling of Zipp's other wheels, the 454's HexFin dimples are strategically placed in small, fin-shaped clumps above the deepest edge of each Hyperfoil, a collaboration that Zipp finds most efficiently manages airflow.
In combination with the SawTooth rim shaping, all these design changes mean that, in theory, this wheelset is ultimately faster than any other wheelset of similar depth that Zipp has made. If the 404 NSW—having dethroned its 404 Firestrike predecessor—was touted as the pinnacle of Zipp speed and stability, then the 454 appears poised to set yet a new bar for capable versatility. We haven't seen the raw wind tunnel data and we are in no way aerodynamicists, so it's prudent to take some of the above claims with a healthy grain of salt. However, with Zipp's race-bred history, it's a safe bet that these wheels at least match other high-end offerings. Whatever the case, one thing is for sure: The 454 NSW stands alone with an aesthetic that is guaranteed to garner attention at weekend club rides, coffee shop gatherings, and race venues alike.
With all that speed on tap, we're happy to know that Zipp now offers the 454 NSW in a disc brake version. We're pretty confident we'll see disc brakes take over in the peloton in the next few years (watch the grand tours this year), as some pretty big races wins have been captured on disc wheels. The better braking in all conditions cannot be denied and the weight just keeps coming down. As far as aerodynamics go, we feel these wheels don't surrender much to the rim brake versions. Kudos go to Zipp for spec'ing Centerlock hubs which offer a lighter, stiffer, and easier solution than 6-bolt hubs. The confidence on offer squeezing a dedicated braking surface as well as the peace of mind knowing that a heat related tire blow out from overzealous braking is a thing of the past, is reassuring.
Zipp's Cognition hubset (also first seen on the 404 NSW) makes an appearance in the 454 NSW and is arguably as innovative as the rims. The Cognition is centered on Zipp's Axial Clutch freehub mechanism, which engages by way of two Metal Injection Molding (MIM) rings. One ring is mated to the freehub body and one mated to the hub body, and the two rings are machined like a ratchet, so they ramp off of each other while freewheeling but engage each other during pedal input.
Compared to a standard pawl design, which operates like a drum brake, the Axial Clutch's MIM rings engage laterally to reduce friction while freewheeling, so coasting doesn't negate watts already spent. We're familiar with this model, as we've seen similar mechanisms on the designer hubs featured in top-end custom builds for years now, but Zipp is the first to replace the usual tensioning agent (steel springs) with magnets. This substitution further reduces friction between the ratcheting rings, making for what may be the smoothest freewheel on any mass-produced hub set. It's a design that we suspect will eventually be the norm, but—as with innovations in rim shape—Zipp is leading the charge.
In a wheelset of this caliber, even the tiniest details are attended to. Acknowledging that sticker decals break up the clean surface of the rim and impact both aesthetics and aerodynamics, Zipp uses its ImPress graphics process for clean branding that blends seamlessly into the rim's surface. While the speed impact may be negligible, printing the logo directly on the rim eliminates unnecessary sticker edging and ensures that the dimples are unencumbered by imperfect sticker surfacing for a clean, fully integrated logo that won't peel or crack over time. Since they're on a disc brake wheel, the dimples are also not interrupted by a brake track, so they extend all the way to the rim's edge and maximize aerodynamic benefits.
Each wheel includes Zipp Tangente titanium black skewers, Silca valve extenders, a wheel bag, and Zipp rim tape. Please note that Zipp recommends a maximum rider weight of 250lb for this wheelset.
- An aerodynamic wheelset inspired by nature
- Alternating rim depth improves cross winds and aerodynamics
- New ABLC dimples improve air flow and stability
- Carbon fiber rims are light, stiff, and fast
- Centerlock hubs ushers in legit disc brake aero wheels
- Cognition Axial Clutch engages quickly with little drag
- ImPress graphics provide clean and aero decals
- Zipp Speed Weaponry redefines the boundaries of functional, aerodynamic design