OPEN UPPER Frameset

The OPEN U.P.P.E.R. Frameset represents the pinnacle of performance gravel design, combining road bike speed with go-anywhere capability in a lightweight package that helped define the fast gravel category. This frameset delivers speed, fun, and freedom through its revolutionary dual wheel size compatibility and dropped chainstay design—an approach that has become the de facto standard for performance gravel bikes. The U.P.P.E.R. differs from the standard U.P. only in weight, coming in 180 grams lighter while sharing identical geometry, durability, stiffness, tire clearance, and ride capabilities.

Built with OPEN's TRCinTRS technology (The Right Carbon in The Right Spot), the U.P.P.E.R. features a highly refined carbon layup that uses the highest modulus carbon fibers where possible and tougher grades where necessary. This strategic construction maximizes strength, stiffness, and compliance in the areas that matter most. The flat-out downtube places strips of ultra-high modulus carbon far from the center plane to create exceptional stiffness between the steering center and drivetrain, while the signature Wire-Stays, vertically thin chainstays and seatstays, deliver comfort and compliance without sacrificing lateral stiffness for efficient power transfer.

Revolutionary tire clearance makes the U.P.P.E.R. essentially three bikes in one. With 700c road tires installed, it becomes a fast and efficient road machine. Swap to 32–40mm gravel tires and it transforms into a capable mixed-surface bike ready for dirt roads and long adventures. Fit 650b mountain bike tires up to 2.1 inches and it becomes a highly capable off-road machine while remaining impressively quick on pavement. The dropped chainstay design allows these larger tires without requiring wide cranks, enabling riders to use road cranks with a lower Q-factor for optimal pedaling efficiency.

Perfect for riders seeking ultimate versatility without compromise, the U.P.P.E.R. features flat-mount disc compatibility with the U-Turn carbon fork optimized for 160mm rotors using OPEN's innovative Smartmount system that eliminates adapters for a lighter, stiffer, and safer braking setup. Internal cable routing, compatibility with a zero-setback 27.2mm seatpost, ThruThread dropouts, and strapless bag mounts complete this meticulously engineered frameset that performs confidently across road, gravel, and trail configurations.

Key Features

• Frame - U.P.P.E.R. Carbon with TRCinTRS Technology (180g Lighter than U.P.)
• Fork - U-Turn Carbon with Smartmount Flat-Mount Design
• Tire Clearance - 700c up to 40mm / 650b up to 2.1" Mountain Bike Tires
• Design - Dropped Chainstay for Maximum Clearance with Road Crank Compatibility
• Bottom Bracket - 386 EVO with BB86 Shell for Wide Crank Compatibility