Open U.P. 2.0 Adventure Chassis

Gerard Vroomen co-founded Cervélo, helped build one of the most recognized names in performance road cycling, and then stepped away to start something smaller and more deliberate. OPEN Cycle launched in Basel, Switzerland in 2012 with a stated philosophy of working hard to stay small — boutique manufacturing, intentional design, no shortcuts. The original U.P. (Unbeaten Path) followed in 2015 and became one of the most imitated gravel bikes ever made, its dropped drive-side chainstay and road-inspired geometry clearing tires that no performance frame had cleared before. The Open U.P. 2.0 Adventure Chassis is the second generation of that platform in its Adventure configuration — built for the rider who wants the U.P.'s road-informed handling with the added capability of cargo carry, dual wheel sizes, and mixed-terrain versatility.

The frame is full carbon pre-preg, manufactured in Portugal, with a multi-modulus layup that assigns different fiber grades to different structural roles. High-modulus and ultra-high-modulus fibers run through the main tubes for stiffness and efficiency; lower-modulus, tougher carbon is used in the head tube area specifically to absorb impacts rather than concentrating them. The ultra-thin seatstays are a deliberate engineering choice — not a byproduct of weight reduction — designed to let the rear triangle absorb road and trail vibration in a way that a conventionally stiff seatstay cannot. Frame weight in size medium is approximately 995g. T47 threaded bottom bracket, a Universal Derailleur Hanger rear dropout for broad drivetrain compatibility, and fully internal cable routing complete the foundation. OPEN builds size-specific geometry into each of the five sizes rather than scaling a single template, so the handling character — quick, road-informed, precise — is consistent whether you're on an XS or an XL.

The Adventure chassis is defined by its U-Turn Adventure fork, which is what separates this build from the race-focused U.P.PER. 2.0. The Adventure fork carries patent-pending direct-mount cargo slots — soft bags attach to the fork blades without cages, the lightest possible load-carrying setup for bikepacking. Standard cargo cage mounts are also present for conventional setups. Tire clearance is 700c up to 46mm and 650b up to approximately 2.1", with dual wheel size compatibility retained where the UPPER 2.0 race model dropped it. The chassis package is complete: included alongside the frame are the U-Turn Adventure fork, headset, seatpost, and the OPEN B.A.R. — a one-piece carbon integrated bar and stem with a 15mm fore/aft reach micro-adjustment system in 5mm increments, available in 10 configurations across stem lengths from 60 to 130mm and bar widths from 380 to 440mm. Everything needed to build the bike short of drivetrain and wheels is already here.

Design Benefits

1. A fork built for cargo, not just cleared for it — The U-Turn Adventure fork's patent-pending direct-mount cargo slots are engineered specifically for soft bag attachment without cages, eliminating the weight and rattle of conventional cage setups. Standard cage mounts are also present for riders who prefer them. This is the detail that makes the Adventure chassis a genuine bikepacking platform rather than a race frame with a bag strapped on.
2. Multi-modulus layup with deliberate compliance built in — OPEN doesn't use a single carbon grade throughout the frame. High-modulus fibers provide stiffness where you need it; tougher lower-modulus carbon absorbs impact in the head tube; ultra-thin seatstays flex intentionally to dampen the vibration that makes gravel riding fatiguing over long days. The result is a frame that feels both responsive and livable across mixed terrain.
3. 700c and 650b in one platform — The Adventure chassis clears 700c x 46mm and 650b x 2.1" — a meaningful range that lets you run fast, narrow rubber for road-mixed days or drop to 650b with a wider tire for serious off-road or loaded touring. That dual-wheel versatility is a deliberate feature of the Adventure model, and it makes one frame genuinely serve multiple purposes.
4. A complete chassis, not a bare frame — The $4,500 includes the frame, U-Turn Adventure fork, headset, seatpost, and the OPEN B.A.R. integrated cockpit with its 15mm micro-adjust reach system. That last detail matters: the B.A.R. comes in 10 size configurations and lets you dial position without swapping the bar. You're pricing in a custom-fit cockpit, not just a frame.

Final Take

The OPEN U.P. 2.0 Adventure Chassis is for the rider who wants a fast, road-informed gravel bike that also carries gear without compromise. The U.P. platform has always ridden like a road bike that happens to clear large tires — quick-handling, stiff, immediately responsive — and the Adventure fork extends that foundation into bikepacking and multi-surface territory without softening the character. The complete chassis package, size-specific geometry, and T47/UDH spec make it one of the more thoughtfully assembled gravel framesets at this price.