The definition of what’s considered “road cycling” has evolved to include gravel and dirt as well as pavement. At the same time, bikes are evolving to meet the fit requirements of smaller riders. Meeting these two distinct needs was the driving force behind the new Zipp 303 Firecrest 650b Carbon Clincher Tubeless Disc-brake wheelset.

This wheelset shares the same proven innovations as the full line of Carbon Clincher Tubeless Disc-brake wheels. The difference is size. A 650b wheel has a 584mm bead seat diameter rim vs. the 622mm diameter of a standard 700c road rim.

Foremost, the 303 Firecrest 650b Tubeless Disc-brake wheelset is an ideal choice when the pavement ends. The smaller rim size provides room within frames and forks for larger tyres, 28mm or wider, that deliver increased comfort, compliance, and cornering performance. With more tyre between the rim and the ground, the overall wheel diameter including the tyre is similar to a standard 700c wheel and road tyre combination.

Back on the pavement, the 650b is a better fitting wheel for smaller athletes riding compatible frames. For too long, many smaller cyclists have trained and raced on standard 700c wheels, losing out on the advantages of a proper fitting wheel such as improved handling and the elimination of front wheel toe overlap.

Zipp’s updated 650b rims have an internal width of 21mm. The 303’s 45mm rim depth is an ideal option for every terrain or road surface. Designed to be tubeless compatible, this setup option allows you to run lower tyre pressure for increased comfort and cornering grip along with a reduced chance of pinch flats. For added security, the rim bed features internal ridges to lock the tyre’s bead in place, even when ridden at lower tyre pressures.

A new carbon fiber layup keeps weight low while maintaining the Firecrest Carbon Clincher’s proven durability. To maximise aero benefit, Zipp’s ABLC dimples extend all the way to the outer edge of the rim. The robust 77D/177D hubset, paired with 24 Sapim CX-Sprint spokes front and rear, keeps the wheels stiff and responsive.

To ensure compatibility with any bike, their versatile 77D/177D hubs come with swappable end caps to work with QR’s and thru-axles, including 12x100mm and 15x100mm front thru-axles as well as 12x142mm rear thru-axles. The 177D rear hub is also XDR driver body compatible for use with SRAM 10-42 cassettes.

With the introduction of the 650b, the Zipp 303 Firecrest—now more than ever—is a wheel without limits.


Firecrest - With the new proprietary Firecrest rim shape in their 202, 303, 404 and 808 Firecrest wheels, Zipp wheels make a bigger difference in more ways than ever. Not only is Firecrest more aerodynamic than any other rim design, it improves handling in crosswinds and overall ride quality.

Carbon Clincher - Their superior Carbon Clincher technology is the culmination of two years of intensive prototyping and testing. We worked with their composites supplier to develop an exclusive heat-resistant resin based on the materials used in motorsports brake systems. This proprietary technology improves heat management so substantially that all Zipp Carbon Clinchers pass stringent CEN safety standards.


Zipp Tangente Quick Release Skewer
Zipp Tubeless valve – factory installed
Tubeless rim tape – factory installed
Valve core removal tool
Zipp 77D/177D thru-axle caps to fit 12x100, 15x100 and 12x142 dropouts
Freehub body spacer – 11 to 10 speed
SRAM XDR driver body for 177D available separately.


  Front Wheel Rear Wheel
Weight 665g 785g
Hub Used 77D 177D
Hub Width 100mm 135mm
Rim Depth 45mm 45mm
Max Width 28.9mm 28.9mm
Internal Width 21mm 21mm
Spokes Sapim CX-Ray Sapim CX-Ray
Spoke Count 24 24
Spoke Pattern 2 cross -
Spoke Pattern Drive - 2 cross
Spoke Pattern Non-Drive - 2 cross
Spoke Length Drive 254mm / straight pullmm 252mm / straight pull
Spoke Length Non-Drive 252mm / straight pullmm 254mm / straight pull
10 or 11-speed Compatible Hub - Yes
XDR Compatible - Yes
Track Adaptable No No
Dimpled Surface Yes Yes
Nipples Sapim Secure Lock Sapim Secure Lock
External Nipples Yes Yes
Thru Axle Compatible Yes Yes
Tubeless Yes Yes

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