2019 Roval 321 - Rim Brake

Making up about 50% of your total race time, the bike portion of a triathlon is where equipment choices can make the difference between first and fifth. And no other equipment choice will save you more time than a disc wheel. While traditionally-shaped disc wheels are faster than their spoked counterparts, the 321 disc turns conventional design on its head, creating the fastest wheel available.

Disc wheels often fall into two categories—a completely flat shape, with structure coming from carbon fibre and a honeycomb-foam filling, or a spoked wheel that's been faired with a carbon fibre cover. In our quest to break traditions, the 321 uses a single layer of 1k carbon fibre on each side of the wheel, and it all comes together at the brake track bridge. This kind of carbon fibre 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 fibre craftsmen. It's complicated, but the pay-out 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 we 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, we've determined that this isn't the case at all. In fact, our 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, we first designed our optimal aero shape and then worked on our internal stiffness targets to fit within what we consider to be a desirable frame stiffness.

And while light overall weight was a development priority, our focus was aerodynamics. Through hours of Computational Fluid Dynamics (CFD) and testing in the Win Tunnel, we 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 our 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, we've also added CeramicSpeed bearings and DT Swiss 240 hub internals into our 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 Type: Carbon clincher, 2Bliss Ready

• Rim: 321 Disc, Carbon Clincher, 700c, Rim Brake, Tubeless Compatible

• Rim Material: Carbon

• Rim Details: Solid Depth, 27.3mm External Width, 19mm Internal Width

• Braking Surface: Carbon Fibre

• Hub: Roval Disc Hub, DT Swiss 240 Star Ratchet internals, 130x5mm qr compatible, (Convertible freehub)

• Brake Track Height: 12mm

• Bearing Type: Ceramic Speed

• Rim Depth: Solid Disc

• Spokes: Full Carbon Disc

• Rim Width: 19mm internal, 27.3mm external (at brake track)

• Nipple: N/A

• Rear Hub: Roval Disc, CeramicSpeed bearings, DT Swiss 240 internals, 11-speed

• Tire Size: 22mm - 38mm - Max Pressure: 130 psi

• Assembly Method: Handmade

• Weight: Wheelset 1000g

• Extras: Roval padded wheel bag, Roval steel quick-release, Roval tubeless valve, SwissStop Black Prince brake pads, Roval valve pocket covers

• Assembly Method: Hand built at every step - from rim layup to the last nipple turn.

• Weight: 1000g

• System Weight Limit: 240lbs / 109kg - Extras: Roval padded wheelbag, Roval tubeless plugs and tubeless valve, Roval valve pocket covers