Zipp’s 454 NSW wheelset’s unique profile looks extraordinary and isn’t cheap. The Centrelock disc brake 454 NSWs have widths of 17mm internally, and between 26.4mm at their outer edge and 27.72mm at their widest externally.
That distinctive design is said to be based on Biomimicry – applying natural world solutions to manmade objects. Taking the lumpy tubercles on the leading edge of Humpback whales’ pectoral fins as inspiration, Zipp’s engineers came up with the Sawtooth profile to improve airflow across the rim.
Supplied with end-caps and all-road thru-axles, wheel bags and more, they’re not tubeless compatible, and have a maximum recommended pressure of 125psi/8.6 bar and rider weight of 115kg. My set, with quick-release end-caps fitted and 45g of rim tape, weighed 1642g.
Looking at their shape, the cost of these labour-intensive wheels is understandable, but is it worth it?
The overall mass is good, but not exceptional among the competition, as Zipp tends to be a conservative weight shedder. The Cognition hubs feel slick, their Axial Clutch system halving the freehub’s drag when you’re not pedalling, but the front hub is chunkily asymmetric, when slim hubs have been shown to be more aerodynamic.
Large hub flanges, 24 J-bend spokes and rigid rims make the 454 NSWs very accelerative, with instant response to crank inputs.
It’s hard to say if their mass slows climbing speed, as the wheels feel very efficient uphill. I also can’t say they’re more aerodynamic than the 404 for instance, but I doubt they’re slower, based on road tests.
In calm conditions, there’s nothing to tell these rims apart from other competitors, but when speed or the wind picks up, there is.
I headed out on gusty, hard days on hilly, twisty routes to see how they coped… At no point was my control compromised, I didn’t have to fight the front wheel to keep it straight, and the fact I was so unconcerned on days when I’d have plumped for something shallower speaks volumes.
Better control is more efficient, and the confidence these bring allows you to go faster for longer.
1. Hubs: The Cognition hub flanges also feature a Sawtooth profile, but no aero claims are made for these.
2. Nodes: Each rim has 24 raised nodes to improve aero stability, and each is matched to a spoke.
3. Impress: Zipp’s Impress graphics are printed directly onto the rim, allowing the recessed dimples to work properly.