Zipp 303 Firecrest Carbon Road Wheelset - Clincher $2,724.95
Race with what you train with.
Name any race, and the Zipp 303 has either won it or won a stage in it. Seriously. And now, Zipp has found a way to improve upon perfection with the 303 Firecrest Carbon Clincher. More stable, more aerodynamic, and faster than its predecessor due to the refined 188/V9 rear hub design and a more efficient spoke lacing pattern.
A number of components went into making the Firecrest 303 carbon clincher the strongest and fastest clincher in the Zipp arsenal of "Speed Weaponry." First is the Multi-Material Co-Moulding process that permanently fuses a sub-200-gram aluminum hoop to a dimpled carbon structure that acts as a leaf spring for road vibration and impacts. The next step in the process is the implementation of VCLC, which involves the insertion of a visco-elastic material between carbon laminates in the rim, which delivers a ten percent reduction in road vibration. When it came to carbon resin, Zipp faced obstacles in relation to applied heat. It found that clincher rims handle all of the air pressure along with the tire, resulting in catastrophic failure when over-heated. Part of the solution came from the development of the Firecrest clincher rim shape, and the other came out of an exclusive deal with a Formula One carbon resin manufacturer. Together, they worked out a new resin that improves heat dissipation enough to pass European safety testing.
Zipp's Firecrest design is steeped in a wider-is-better ideology. Zipp found that a wider rim offers greater vertical and lateral compliance for increased control, comfort, and rigidity. For the clincher, they found that distancing the hook beads further apart allowed the tire to take on a more stable shape without adding rolling resistance.
For strength and rigidity, the Firecrest 303 utilizes both unidirectional fiber and woven fiber. In this design, unidirectional fibers are used to handle the tensile and comprehensive loading within the rim, and woven fibers are used in the spoke-hole areas. A woven silica-ceramic fabric and a woven carbon fabric encapsulate the braking and tire-mounting surfaces. The combination of fiber patterns creates the highest stiffness-to-weight ratio in Zipp production.
The Firecrest is Zipp's most ambitious rim shape to date. Designed to account for differences in airflow between tubulars and clinchers, the Firecrest 303 carbon clincher maintains a rim depth of 45.0mm and an aero width of 28.5mm. Using computational fluid dynamics, Zipp improved crosswind stability by moving the center of pressure towards the steering axis. This creates the most stable and predictable deep-section rim on the planet. To counteract drag, the Firecrest maintains a near-constant width around the spoke bed to control the air flow around the back half of the wheel where the curved sections stick the airflow to the rim surface, forcing the flow into a high energy state that creates a turbulent boundary layer near the surface. This action reduces pressure drag, and increases skin friction which is ten times lower than pressure drag.
For the build, Zipp used its proprietary 88 hub on the front and the new 188/V9 on the rear. This new hub has larger precision Swiss steel bearings for increased durability, and it provides an increase in lateral stiffness over its predecessor. According to Zipp, this new bearing/cartridge system also delivers a 25% increase in torsional stiffness compared to the leading competitive hubs currently available. The wheels still receive an 18/24 Sapim X-Ray spoke configuration, but on the rear wheel Zipp moved from a radial non-drive side and two-cross lacing drive side pattern to its new "virtual three cross" lacing configuration on both sides. Zipp uses the word "virtual" here to describe the manner in which one spoke doesn't actually contact the other two spokes it crosses. The result is a stiffer overall construction that more effectively transfers power directly to the rear wheel, which is crucial for those out-of-the-saddle sprints and climbs.
The Zipp Firecrest 303 Carbon Clincher Wheelset is available in the color Black. The rear wheel is available with your choice of a Shimano/SRAM or Campagnolo 11-speed compatible freehub body. Each wheel includes a Zipp steel skewer, alloy valve extender, rim strip, and Zipp Tangente cork brake pads.
Please note that Zipp's Tangente Platinum Pro and cork brake pads are designed specifically for use with its carbon clinchers. Zipp also recommends a maximum rider weight of 250lb for these wheels.