Zipp's 303 Firecrest Tubular wheel has proven itself time and time again in the Spring Classics, as well as in countless road and cyclocross races. The unmatched aerodynamics and near legendary strength of the 45mm profile rim have already been matched with a disc hub in a first generation, but now Zipp has engineered a new disc hub that is not only smooth rolling and has a 6-bolt disc rotor mount, but also utilizes a straight-pull spoke and lacing design that better integrates with the rim, provides more stopping power and manages the torque of disc braking, but is also very light.

The second generation rear disc hub comes in at 177 grams- which is an attention grabber, for sure. However Zipp has also addressed a challenging aspect of the previous design as well- the bearings. Now Zipp presets the bearing pre-load, so you don't need to worry about adjusting them. The older system was a little too sensitive and many riders had difficulty either running the pre-load too loose or too tight, both of which could result in bearing or shell damage. The bearings themselves have also been upgraded and have an improved seal that keeps them running clean and fast with the 17mm aluminum axle. While newly designed quick releases and end caps are standard, the 135mm wide 177D rear hub is also compatible with thru-axle systems, both 12/135mm and 12/142mm. Simply change out to the included proper end caps; a process that can now easily be done by hand.

The rear hub is laced to disc specific 303 Firecrest rim with a proprietary spacing and lacing system that starts at the hub. 24 Sapim CX-Ray lightly bladed, straight-pull steel spokes are used, along with Sapim's external Secure Lock nipples to ensure excellent tension for lateral stiffness and vertical compliance, but also to prevent hub wind-up or torque damage from the disc rotor. Lacing is 2x on both drive and non-drive sides. ... Read More