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 same pre-adjusted bearing system you have the front is used for the rear hub, as is the lightweight oversized axle. While the 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.

The rear hub is laced to the disc specific 303 Firecrest clincher 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, which makes truing and tensioning less variable.

Firecrest technology has changed the aero wheel industry, and the 45mm 303 has been a direct beneficiary and proponent of the wider rim profile. Of course the shaping of the back half of the rim and the aerodynamic magic of the ABLC™ rim dimples are specific to Zipp's Firecrest wheels, delivering scintillating speed, but also impeccable stability in wind, at any yaw angle. The rim also rides beautifully, not harsh or squishy. As the best all around option in the line-up, the 303 can rail corners, slip through the air, dominate the cobbles, tear through sand or mud, and keep you fresh and in control all day long. This disc brake version even saves weight and expense by eliminating the Showstopper brake track required for rim brake versions.

Disc cyclocross is here to stay, disc gravel road is building a huge grassroots following, and the pro peloton is moving towards disc brake options. The Zipp Firecrest 303 Clincher Disc Brake wheels are here to drive the pack. Lightweight, with advanced hub and rim technology, and the all-conditions advantage of disc brakes, this is a go-to choice of discerning pro and amateur riders all over the world. It is time to make your move.