This new 53/58mm deep rim shape is claimed to simultaneously reduce aerodynamic drag and side force.
Zipp is trying to reinvent the wheel - literally. This week the Indianapolis-based wheel maker that's owned by SRAM launched its new Zipp NSW 454 carbon clincher wheels. As this video illustrates, the design is a radical departure from traditional road cycling wheel shapes, with the objective of maximizing aerodynamic gain, but not compromising rider control in heavy crosswind situations. Of course bleeding edge technology doesn't come cheap. These new wind cheaters will set you back a cool $4000.
Utilizing the principles of the emerging science of biomimicry, Zipp engineers studied the environment around them for instances of how nature solved similar problems of speed, control, and efficiency for the next generation of Zipp wheels. They ended up focusing on the sea.
Think of a humpback whale's fast but graceful movements thanks to the special features on the leading edge of its pectoral fins, or the unique micro texture of a shark's skin, which gives it the ability to glide effortlessly through the water. These structures inspired Zipp advanced development engineers to apply biomimicry to solve the complex challenge of designing a wheel that reduces both aerodynamic drag and side force.
The most visually striking and functionally important innovation in the 454 NSW is the rim's sawtooth shape. This new 53/58mm deep rim shape is claimed to simultaneously reduces aerodynamic drag and side force.
It accomplishes this with a series of fin-shaped nodes along the inner diameter of the rim that work together with Zipp's new dimples for improved airflow. The result is Zipp's highest performing wheelset at all wind yaw angles. This is important because higher wind yaw angles are where bike handling is most affected by the wind.
The rim shaping dimples help to stabilize handling in gusting wind by increasing wind vortex shedding frequency. Lower frequency shedding produces larger, more powerful vortices. In cycling terms, this unstable situation is often referred to as "buffeting." The higher frequency vortex shedding creates a greater number of smaller, less powerful, yet more predictable vortices leading to greater wheel stability. This added stability, claims Zipp, translates into greater rider control, thereby saving energy that is typically expended trying to hold a line in gusting wind.
The 454 NSW also features silicon carbide Showstopper brake track and ImPress NSW graphics, which prints graphics directly onto the rim, reducing weight and helping the dimples to do their job.
The wheels are designed for use with 23c or 25c road tires. These are not your next gravel adventure wheel.
The new wheels roll on Zipp's Cognition hubset with Axial Clutch technology that allows the freehub's ratcheting mechanism to deliver less mechanical drag compared to conventional three pawl hubs.
Each Indianapolis-made 454 NSW rim requires 12 hours to create. After each rim is laid up, molded, drilled, printed, and inspected, every wheel is assembled and tensioned entirely by hand in Indianapolis. The 454 NSW rims are laced to Portuguese-made Cognition hubs using Belgian Sapim CX-Ray spokes and Secure Lock nipples.
Each wheel includes Zipp Tangente titanium black skewer, Zipp valve extender by Silca, Zipp individual wheel bag, Zipp Tangente Platinum Pro Evo brake pads, Zipp Tangente tube 700c x 20-28mm, and Zipp rim tape 700c x 20mm. MSRP for the front wheel is $1800. The rear sells for $2200.
To learn even more about the new Zipp NSW 454 carbon clincher wheels, check out another video, this one courtesy of the Global Cycling Network, which got some face time with key Zipp staffers - and got to take the wheels for a spin
For more info, please visit zipp.com.