Zipp 808 Firecrest Carbon Road Wheel - Clincher $1,637.95
Aero at its core.
When it comes to sheer speed, nothing overtakes the Zipp 808. It's been proven from Kona to Paris, and with addition of Firecrest technology, the Zipp 808 Firecrest Carbon Clincher has raised the bar even higher. New to this year, the 808 Firecrest receives Zipp's new 188/V9 rear hub, which increases both rigidity and durability without any sacrifice to weight.
A number of components went into making the Firecrest 808 carbon clincher the fastest and most aerodynamic clincher in the Zipp arsenal of "Speed Weaponry." First is the Multi-Material Co-Molding 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 without setting limitations on rider weight or brake pad options.
Zipp's Firecrest design is steeped in a wider-is-better ideology. Zipp found that a wider rim offers greater vertical/lateral compliance for increased control, comfort, and rigidity. For the clincher, it 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 808 utilizes both unidirectional fiber and woven fiber. With 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 808 carbon clincher maintains a rim depth of 81.0mm and a maximum width of 27.5mm. Remarkably, the Firecrest 808 performs better in a crosswind than the standard 404, and outperforms competitor's 91mm wheels. 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. This forces 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 808 Firecrest Carbon Clincher Road Wheel is sold individually and are available in the colors Black or White. The rear wheel comes with either a 11-speed Shimano/SRAM or Campagnolo compatible freehub body. The front wheel weighs in around 810 grams and the rear tips the scales around 920 grams. Each wheel includes a Zipp steel skewer, an alloy valve extender, a rim strip, and Zipp Tangente cork brake pads.
Please Note that Zipp's Tangente cork brake pads are designed specifically for use with their carbon clinchers. Use of brake pads other than these is not recommended and will also void the wheel warranty. Also, Zipp advises that riders of the 808 Firecrest do not exceed 250lb.