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321 Disc
The world’s most aerodynamic wheel
321 Disc
The world’s most aerodynamic wheel
what it’s for, why it’s great
The clock is the toughest competitor of them all. The revolutionary 321 is purpose-built to give you an edge in the race against time. In real-world conditions, it is the most aerodynamically efficient wheel ever made; featuring a unique asymmetric, lenticular construction that cheats wind and conserves precious watts. At 1000 grams, it’s also the lightest production disc around.
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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
Full carbon clincher, 2Bliss Ready
Carbon
Rim: Carbon Fiber
Disc: Disc brake only
12mm
Solid disc
19mm internal, 27.3mm external (at brake track)
Rim: Roval Disc, CeramicSpeed bearings, DT Swiss 240 internals, 11-speed
Disc: Roval Disc 142x12, CeramicSpeed bearings, DT Swiss 240 internals, 11-speed
Handmade
Roval padded wheel bag, 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
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
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.