Specialized Roval 321 Rear Wheel - Rim Brake - Carbon / Gloss Black (700C)

Disc wheels often fall into two categories—a completely flat shape, with structure coming from carbon fiber and a honeycomb-foam filling, or a spoked wheel that's been faired with a carbon fiber cover. In Specialized quest to break traditions, the 321 uses a single layer of 1k carbon fiber on each side of the wheel, and it all comes together at the brake track bridge. This kind of carbon fiber is rarely used in bicycle components due to its high manufacturing cost, but it offers a bevy of performance benefits. This coveted carbon is much lighter than other layups, like 3k and 12k, and it can only be laid by the most skilled of carbon fiber craftsmen. It's complicated, but the payout is worth it, as it delivers a supple ride and one of the lightest disc wheels available. And in the real world, this means that it'll spin-up quickly and reduce fatigue over the long haul.

Stiffness is often the “hot-topic” in the disc wheel world, but Specialized think it’s an interesting conversation. It's long been thought that efficient power transfer and high stiffness are directly correlated, but through extensive field testing, they've determined that this isn't the case at all. In fact, their initial disc was so stiff that, under power, it wouldn't flex with the frame and this caused brake rub. This wrongly creates the perception of a flexy wheel, when really, the wheel is actually too stiff. In order to solve the brake rub problem, Specialized first designed their optimal aero shape and then worked on their internal stiffness targets to fit within what they consider to be a desirable frame stiffness.

And while light overall weight was a development priority, Specialized focus was aerodynamics. Through hours of Computational Fluid Dynamics (CFD) and testing in the Win Tunnel, they developed a new-to-category shape that's optimized to work with a tire for on-bike airflow. What this translates to is an all-carbon disc wheel that, on the non-drive-side, has a shape that's as aerodynamic as the current understanding allows, and a drive-side shape that's as aerodynamic as the wheel-dish and derailleur clearance will allow for.

To save every possible watt, Specialized have also added CeramicSpeed bearings and DT Swiss 240 hub internals into their hub. Each 321 Disc wheel is also 2Bliss-Ready out of the box and comes with a padded wheel bag, quick-release, tubeless valve, and SwissStop Black Prince brake pads.

Designed for the most uncompromising athletes in the world, with engineering to match, the 321 Disc is the world's most advanced disc wheel for your race against the clock.

• Rim: 321 Disc, Carbon Clincher, 700c, Rim Brake, Tubeless Compatible
• Rim Details: Solid Depth, 27.3mm External Width, 19mm Internal Width
• Hub: Roval Disc Hub, DT Swiss 240 Star Ratchet internals, 130x5mm qr compatible, (Convertible freehub)
• Bearing Type: Ceramic Speed
• Spokes: Full Carbon Disc
• Nipple: N/A
• Tire Size: 22mm - 38mm - Max Pressure: 130 psi
• Weight: Wheelset 1000g
• Assembly Method: Hand built at every step.
• System Weight Limit: 240lbs / 109kg - Extras: Roval padded wheelbag, Roval tubeless plugs and tubeless valve, Roval valve pocket covers