Racing on the track, small increases in efficiency can yield huge dividends. The 404 Firecrest Track Tubular rear wheel is assembled with ZIPP's stiff and aero 58mm deep 404 rim and connects it to the innovative 333 rear hub with the world's best spokes, the Sapim CX-Ray. Together these components deliver unrivaled stiffness and speed. The 404 Firecrest rim strikes the ideal balance of rapid acceleration and aero efficiency to excel in any track event. The same aerodynamics, stiffness and stability that made the Firecrest shape a revolutionary technology out on the road produces speed on the track. At the heart of this 860g rear wheel is the 333 track rear hub. Designed from the ground up for the rigors of track racing, this impressively light weight hub makes use of oversized hub bearings and an oversized axle that work together to produce a wheel with superior load carrying capacity and bombproof reliability. The 333 hubshell also incorporates industry leading aerodynamics and asymmetrical hub flanges deliver balanced spoke tension, immediate acceleration and flawless tracking through turns.
Firecrest Technology In developing the original 303 wheels, 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 ZIPP 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.
You'll also see the rim skin is embossed with lot's of dimples of different diameters in a pattern which forces the airflow to form thinner, turbulent boundary layers. This significantly reduces the interference drag. The turbulent layer also adheres to the wheel skin throughout an increased airflow angle of attack, resulting in significantly lower drag in cross-wind situations, which means you have even more control with the ABLC (Aerodynamic Boundary Layer Control) rim. ABLC increases handling performance by minimizing the low-pressure wake left behind the wheel, allowing for greater tire choice with fewer aerodynamic side effects than seen with other designs. Zipp's exclusive VCLC (Visco-Elastic Constrained Layer Control) technology dramatically reduces rider fatigue, particularly in the hands, arms, neck, and posterior - while greater control of the tire contact patch simultaneously improves cornering grip and minimizes rolling resistance.
For tubular tires only! Only use rim cement (for example Continental). Tufo tubular tire gluing tape must not be used!