321 Disc

The world’s most aerodynamic wheel

321 Disc
321 Disc
321 Disc
321 Disc
321 Disc bag
321 Disc Titanium Quick-Releases
321 Disc
321 Disc
321 Disc
321 Disc
321 Disc bag
321 Disc Titanium Quick-Releases

321 Disc

The world’s most aerodynamic wheel


Aero’s leading edge

The tubeless ready, 19mm inner width of the 321 rim is tailored to fit modern, wider tires. The wheel itself is the result of rigorous testing in our wind tunnel to ensure that it delivers maximum laminar flow and aerodynamic efficiency with those same wider tires. Through innovative geometry and layup we created a 1000 gram wheel; no production disc is lighter.

Asymmetrical sensibility

The non-drive side of the 321 is the most aerodynamically efficient shape possible; it bows in a lenticular form from the hub to the rim. We would have done that with the drive side as well, but we had to make room for the cassette and chain, so that side is flatter, but still very slippery.

Silky bearings save precious watts

CeramicSpeed bearings are the lowest friction, most energy efficient bearings money can buy. When seeking out hundredths of seconds and applying every available watt of energy to maximize speed, this level of attention to detail matters. Keeping with this theme of performance above all else, the 321 hubs are finished with precision DT Swiss 240 freehub internals.

The crucible of truth

Long before seeing any pavement, the 321’s shape was honed through successive iterations of prototypes. Each one of those prototypes was fed into our wind tunnel, tested for all possible conditions, then sent back for revision. The final production wheel represents thousands of hours spent testing in this exacting arena and the results speak for themselves, including Ironman World Records, UCI World Championship titles, and Grand Tour stage wins.

Product Specifications

Technical specifications

Rim type

Full carbon clincher, 2Bliss Ready

Rim material


Braking surface

Rim: Carbon Fiber

Disc: Disc brake only

Brake track height (rim)


Rim depth

Solid disc

Rim width

19mm internal, 27.3mm external (at brake track)

Rear hub

Rim: Roval Disc, CeramicSpeed bearings, DT Swiss 240 internals, 11-speed

Disc: Roval Disc 142x12, CeramicSpeed bearings, DT Swiss 240 internals, 11-speed

Assembly method



Roval tubeless valve, Roval valve pocket covers, Roval steel quick-release (rim only), SwissStop Black Prince brake pads (rim only)


Rim: 1005g

Disc: 1015g

Tire pressure recommendations

Still Have Question If Our Components Are Right for You? 

Call Us at 1 (877) 808 - 8154

Computational fluid dynamics
Computational fluid dynamics

Leveraging powerful Computational Fluid Dynamics (CFD) was key to the aerodynamic optimization of the 321. CFD enabled our engineers to very closely estimate the drag that the wheel would generate. They then utilized that data to revise the shape of the 321 in the computer until it was close to perfect. 

Win tunnel
Win tunnel

Working from the data gleaned from the CFD process, our technicians created 3D printed models of the 321 and tested them in our wind tunnel. Working the physical model at various yaw angles, with a real tire mounted, installed in a real bike, the team generated drag data that was used to further optimize the 321 design.

Select variant

321 Disc

Brake Type


Rim Type



Carbon/Gloss White

Have a Question? 

Give Us a Call at 1 (877) 808 - 8154