In developing the original 303 wheelset, Zipp discovered that a wider rim increases lateral stiffness for sprinting and cornering while also providing greater vertical compliance for greater control, comfort and durability. That wider rim profile led us to develop our Firecrest technology, which revolutionized aerodynamic efficiency and stability for carbon wheels. The proprietary Firecrest rim shape optimizes the aerodynamic profile of the front half and – here’s the revolutionary part – the back half of the wheel. Firecrest moves the wheel’s center of pressure to be more in line with the steering axis for stability in even the stiffest crosswinds. All of that innovation along with the precision control of disc braking gives you a wheel that’s as smooth as it is tough. The 303 has been completely redesigned with Firecrest® shaping. The Carbon Clincher preserves the aerodynamic advantages of its tubular brother, while adding the convenience of a clincher tyre. And at just 900g, it’s light enough to climb up the steepest gradients with ease. The new wheels retain all the small details that make Zipp wheels what they are. Exposed spoke nipples sit in the aerodynamic shadow of the rims, keeping serviceability simple without compromising speed. And our signature ABLCâ„¢ rim dimples squeeze every last second of performance possible. For the disc wheel a newly designed 11-speed compatible hub has been designed with larger Swiss stainless steel bearings with a custom cartridge in the rear hub shell provide increased durability. The hub geometry and virtual 3-cross spoke-lacing pattern are optimized for reliability as well as exceptional stiffness, resulting in efficient power transfer and quick acceleration. The result is superior performance in conditions ideal for disc-brake riding. Firecrest® – A better wheel in every way. Zipp's proprietary Firecrest® rim rewrote the fundamentals of wheel making, resulting in improved aerodynamics, ride quality, wheel strength and stability in even the strongest of crosswinds. As a result, the entire Firecrest family of wheels makes a bigger difference in more ways than ever. 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. The performance benefits are substantial. The 303 Firecrest (45mm rim depth) has become the go-to wheel for the Omega Pharma – Quick-Step Cycling Team at the Spring Classics and the wheel of choice for many of the women on Team Exergy TWENTY12. Zipp used Computational Fluid Dynamics (CFD) post-processing capabilities to maximize aerodynamics and minimize wind-induced steering torque, resulting in a 202 Firecrest Carbon Clincher that is faster and better handling than a classic box-section road wheel. Zipp's Firecrest rim shape improves stability by moving the wheel’s center of pressure aft and downward to sit almost directly over the steering axis, where wind-induced steering torque has a minimal effect. More Stability During the design process for Firecrest, Zipp realized that the advanced mathematics and massive computing power that helped them 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 303 Firecrest Carbon Clincher, they have 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. More Strength As Zipp discovered when developing the Zipp 303 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 303 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. Carbon Clinchers – A new chapter in speed Zipp Carbon Clinchers have been described as the most heavily anticipated wheels of all time. During the two-year development process, we designed new clincher-specific approaches to prototyping, testing, materials, and manufacturing. The end result is worth the wait. Optimized Materials When a wheel with carbon braking surfaces encounters a long, technical descent, spikes in rim temperature and tire pressure can impact braking and handling – especially with carbon clinchers. To solve this challenge, chemists and engineers from our composites supplier made repeated visits to Zipp and developed an exclusive heat-resistant resin based on the materials used in motorsports brake systems. This proprietary technology improves heat dissipation so substantially that all Zipp Carbon Clinchers pass stringent CEN safety standards without any limitations on rider weight or brake pad choices – a certification that no other full-carbon clincher wheelsets have achieved. Optimized aerodynamics Wind tunnel development is a cornerstone of how Zipp creates the world’s fastest wheels. Using semi-structural prototypes, we can quickly and accurately evaluate dozens of potential rim shapes. But the prototyping technology that works for tubulars can’t support fully inflated clinchers. So we developed an entirely new system where plastic skins are applied to a fully structural interior skeleton. This allowed us to refine carbon clincher rim shapes that perfectly match the distinct airflow patterns created by clincher tires. This process led directly to the Firecrest rim shape that has improved aerodynamics, stability, strength, and comfort in our tubular and clincher wheels. Optimized ride quality With the Firecrestâ„¢ rim shape, Zipp Carbon Clinchers are the first to offer the superior aerodynamics, handling, comfort, and road feel of a wide rim body. The added width between the clincher hook beads increases air volume in the tyre, which means a lower chance of pinch-flatting….
– Zipp 303 Firecrest Carbon Clincher Disc Rear Wheel Performance Wheels – £999 (RRP – £)
