Stable, Strong, Fast, as avantages of Firecrest finish on the carbon rims & wheelsets : 
1. ZIPP 404 Firecrest with more stability.

During the design process for Firecrest, 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) software, 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. With the zipp 404 Firecrest Carbon Clincher, we’ve achieved a near neutral steering torque. In real-world conditions, Firecrest rims are markedly more stable than other rims of equal or even shallower depth.

2. ZIPP 404 Firecrest with more strength.

As we discovered when developing the Zipp 404 to thrive under unforgiving conditions at the Spring Classics, 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. The Zipp 404 Firecrest is a proven performer on the open road, cobblestones or rough cyclocross courses. In both tubular and Carbon Clincher versions, the wider design places more rubber on the road while cornering without adding rolling resistance. The new Zipp 404 Firecrest Carbon Clincher uses a new resin system that builds on Firecrest’s foundation of strength.

3. ZIPP 404 Firecrest with more speed.

Firecrest technology, discovered as we developed our Carbon Clinchers, refocused our thinking to concentrate not only on the front half of the wheel, but also the back half. 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.

According to the riders' feedback so far, Firecrest design is a more advanced surface treatment in speed biking on the road and on the mountain.