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Learn More About the Firecrest Rim Shape from Zipp

zipp firecrestFor every rider, every discipline, and every ability level, carbon aero wheels truly make a difference. If you're looking to add to your advantage out on the bike course then check out the Zipp Firecrest 404 / 808 Tubulars or Carbon Clinchers. The radical Firecrest rim shape is more aerodynamic than any other rim design out there and at the same time it improves handling in crosswinds which improves the overall ride quality.

"This is a product that a lot of people have been waiting for, and we wanted to give them something unlike any other wheel on the market. We spent two years optimizing our carbon clincher technology and it's probably the biggest leap forward we've ever made." said Zipp Technical Director Josh Poertner.

More speed.
Discovered as we developed our carbon clinchers, Firecrest refocused our thinking from the front to the back of the wheel. Previous rim shapes were designed to smooth airflow coming off the tire, and tapered inward from the widest point of a toroidal bulge. But Firecrest rims have a less pronounced bulge and maintain a near-constant width almost all the way to the spoke bed. Without giving up the proven benefits of the toroidal shape, Firecrest is the first aero profile that effectively controls airflow around the back half of the wheel.

The performance benefits are substantial. With Firecrest, the latest 404 Tubular (58mm rim depth) matches the aero performance of the pre-Firecrest 808 (81mm depth). And the new 808 Tubular is faster than any competitor's 90mm rim.

See how the quest for the best carbon clincher in the world changed rim shapes forever in this video interview from Zipp.


More stability.
During the design process, we realized that the advanced mathematics and massive computing power that helped us create a faster wheel could also help reduce the impact of crosswinds on handling. Using computational fluid dynamics (CFD), we've discovered subtle variations in rim shape that improve stability without increasing aerodynamic drag. By moving the center of pressure - the focal point of side forces on the rim - to its optimal location near the steering axis, Firecrest offers stable, predictable handling at every wind angle. In real-world conditions, Firecrest rims are markedly more stable than other rims of equal or even shallower depth.

More strength.
As we discovered with designs like the Paris-Roubaix-winning 303, a wider rim increases lateral stiffness for sprinting and cornering yet offers greater vertical compliance for more control, comfort, and durability on rough surfaces. The same holds true for Firecrest rims. In both tubular and clincher versions, the wider design better protects tires and places more rubber on the road while cornering without adding rolling resistance.

For additional information on the Zipp wheel product line with Firecrest technology visit: www.zipp.com/wheels/