The 303 Firecrest Tubular Disc-brake wheelset, pro proven in cyclocross, is now even better and lighter. At the center of the wheelset is Zipp’s 77/177D hubset, an innovation that results in improved stiffness, durability, simplicity and usability. 
 
The 77/177D hubset is the perfect compliment for the leading aerodynamics, ride quality, stability and rim strength of Zipp’s Firecrest rim technology. That means you get the unmatched performance of the 45mm-deep 303 Firecrest rim proven with victories multiple victories at Paris-Roubaix, the Tour of Flanders and pro cyclocross races. And when it’s time to scrub off speed or stop, you won’t have to tense up and ‘grab a handful.’ You have the consistency and power of disc brakes – precision modulation and stopping power is at your fingertips. On top of that, the revised 303 Firecrest Tubular Disc-brake wheelset is 35 grams lighter than its predecessor. 
 
You’re at the helm of a serious Speed Weapon that helps speed up and smooth out even the most chaotic courses. That’s true even when the conditions and terrain get crazy… in cyclocross… gravel roads… steep lonely lanes… or even urban assaults. Jeremy Powers (Rapha-Focus) and the Giant Factory Off-Road Team raced Zipp 303 Firecrest Tubular Disc-brake wheels with new 77/177D hubset to great success this season, including Power’s 2015 U.S. national championship victory. 
 
About the 77/177D hubset: 
Bearing preload precision set – that means no pre-load adjustment is needed. 
Improved bearing protection and sealant. 
Includes newly designed quick-release skewers with a wider more ergonomic handle to provide more leverage for opening and closing. When closed, lever contours neatly with the frame. 
Thru-axle compatible. Comes with thru-axle end caps that can be swapped by hand: 
Front: 12x100mm & 15x100mm 
Rear: 12x135mm & 12x142mm 
Proprietary flange geometry and spoke hole attachment pattern with Sapim® CX-Ray® spokes to optimize torsional and lateral stiffness without sacrificing weight or robustness. 
New distinctive hub graphics. 
17mm axle 
 
The 303 Firecrest Tubular Disc-brake wheelset comes with a standard 10/11 speed driver body for SRAM®/Shimano® or for Campagnolo®, allowing you to run a wide range of cassettes. For those looking for a wider gear range, or tackling especially extreme terrain, a SRAM XD driver body for 177D (sold separately) is easily installed to allow for more cassette options. A 1.85mm spacer is included with the XD driver body and is required for use on the 177D hub. XD driver body compatible with 11-speed cassettes only. 
 
About 303 Firecrest rim technology: 
In developing the original 303 wheelset, Zipp discovered that a wider rim increases lateral stiffness for sprinting and cornering while also providing greater vertical compliance for greater control, comfort and durability. That wider rim profile led us to develop our Firecrest technology, which revolutionized aerodynamic efficiency and stability for carbon wheels. The proprietary Firecrest rim shape optimizes the aerodynamic profile of the front half and – here’s the revolutionary part – the back half of the wheel. Firecrest moves the wheel’s center of pressure to be more in line with the steering axis for stability in even the stiffest crosswinds. 
 
Set Weight 1400g 
Max recommended rider weight 250lbs 
 
Front Wheel 
Weight 640g 
Hub Used 77D 
Hub Width 100mm 
Rim Depth 45mm 
Brake Track Width (center) 26.4mm 
Max Width 28.5mm 
Spokes Sapim® CX-Ray® 
Spoke Count 24 
Spoke Pattern 2 cross 
Spoke Length Drive 272mm 
Spoke Length Non-Drive 270mm 
Max Tire Pressure 125psi 
Max Tire Pressure 8.62bars 
Track Adaptable No 
Dimpled Surface Yes 
Nipples Sapim® Secure Lock 
External Nipples Yes 
Thru Axle Compatible Yes 
 
Rear Wheel 
Weight 760g 
Hub Used 177D 
Hub Width 135mm 
Rim Depth 45mm 
Brake Track Width (center) 26.4mm 
Max Width 28.5mm 
Spokes Sapim® CX-Ray® 
Spoke Count 25 
Spoke Length Non-Drive 272mm 
Spoke Pattern Non-Drive 2 cross 
Spoke Length Drive 270mm 
Max Tire Pressure 125psi 
Max Tire Pressure 8.62bars 
11-speed compatible hub Yes 
Track Adaptable No 
Dimpled Surface Yes 
Nipples Sapim® Secure Lock 
External Nipples Yes 
Thru Axle Compatible Yes 
XD Driver Body Compatible Yes