Zipp 303 Firecrest Carbon Disc-Brake Road Wheel - Clincher $1,553.00
The new wave.
If you've been waiting for worthy disc brake-compatible wheels for your road or 'cross bike, it's time to rejoice -- the Zipp 303 Firecrest Clincher Disc Wheel is finally here. And true to the name, these wheels roll on Zipp's 45mm 303 Firecrest carbon clincher rim, and a redesigned version of the 88/188 hub set. So, say hello to better braking, without saying goodbye to light weight or ride quality.
The layup of the rims hasn’t changed from Zipp's venerable 303 Firecrest clincher. That may come as a surprise, as disc brakes negate the need for a braking surface. However, Zipp's engineers found that the 303 Firecrest rim was already optimized in terms of strength and weight, so there wasn't an advantage to be had by changing the rim profile. However, there is one notable change from the rim-brake version, and that is the brake track itself. The standard 303 Firecrest uses a high-abrasion brake track, and the disc brake wheels receive no such treatment. As such, even though there is a vertical sidewall, the 303 Firecrest disc wheels are not compatible with rim brakes.
It follows that the disc version of the 45mm deep 303 Firecrest provides the same advantages as its rim-brake counterpart. The Firecrest shape refers to a wider rim profile, which measures at a 17.25mm internal width. Extensive research has proven that this wider rim shape enhances the grip of your tires by both increasing the size of the contact patch and by increasing the air volume of the tire. Not only does it improve grip, but because the increased air volume allows the tire to deform more naturally over surface irregularities, the wider rim profile enables these wheels to roll faster than comparable wheels incorporating a narrower rim. And in the spirit of quickness, the 303 Disc wheel retains the dimpled surface of the original. Like a golf ball, those dimples create a minor aerodynamic disturbance, effectively creating a pillow of air around the wheel that enables it to cut through the air with less drag.
And, if you're unfamiliar with the Firecrest's aerodynamic advantage, we'll give you a refresher course. The Firecrest was designed to account for differences in airflow between tubulars and clinchers. Using computational fluid dynamics, Zipp improved crosswind stability by moving the center of pressure towards the steering axis. To counteract drag, the Firecrest maintains a near-constant width around the spoke bed in order to control the airflow 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 303 disc wheels, Zipp employs the latest version of their renowned 88/188 hubset. Like previous iterations, it rolls on custom Swiss-made stainless steel bearings. Not surprisingly, the rear hub features a new 11-speed compatible freehub body as well. So, you'll enjoy compatibility with the latest generation of drivetrains, including SRAM's new Red 22 group set. The significant change is the addition of a six-bolt disc rotor mount. Accordingly, the rear hub is spaced at 135mm, or five millimeters wider than a standard rear wheel. This ensures compatibility with the current generation of disc-equipped road bikes.
To cope with the added loads that disc brakes impart, Zipp's engineers have made some modifications to the spoke layout. Where the rim-brake 303 Firecrest uses radial lacing on the non-drive side of the rear wheel, the disc version gets a 'virtual' three-cross build. And in case you're not sure what the 'virtual' means, it's just a reference to the fact that the spokes cross each other at three points, but that they only make contact with one another at two points. Basically, this reduces the occurrence of wind-up when you hit the brakes. So, your stopping is sharp and responsive, instead of being vague.
The Zipp 303 Firecrest Carbon Clincher Disc Wheel is sold individually and with the label color of either Black or White. Additionally, the rear wheel is available with either a Campagnolo or Shimano/SRAM 11-speed freehub body. Please note that rotors are not included with this wheel, and that Zipp does not recommend this wheel for riders exceeding 250lb.