Zipp

303 Firecrest Carbon Wheel - Clincher

Zipp had to think outside of the carbon box in order to remedy the problems that have long plagued carbon fiber clinchers. Luckily, the Firecrest rim shape was born, and the result is an innovative design that can withstand the detrimental heat of braking while retaining the speed and strength necessary for victory in the cobbled classics. The Zipp Firecrest 303 Carbon Clincher Wheels have proven themselves to be the high-watermark in wheel technology and a total game-changer for how you'll ride in the future.

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 the strength and rigidity, the Firecrest 303 utilizes both uni-directional fiber and woven fiber. In this design, uni-directional 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.

The wheels roll on Zipp's 88 and 188 front and rear hubs. Both hubs use Zipp's proprietary, friction-reducing steel bearings, and each have been laced with Sapim CX-Ray stainless steel, ovalized spokes. The front wheel features an 18 spoke radial lacing pattern, and the rear wheel uses a 24 spoke radial/cross lacing pattern.

The Zipp Firecrest 303 Carbon Clincher Wheels are sold individually as either a front or rear wheel, and in the colors Black and Falcon Grey. The rear wheel is available with either Shimano/SRAM or Campagnolo compatible freehub bodies. 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 225lb for these wheels.