bmc gravel bike 2023 BMC Kaius 01 Three Carbon Gravel Bike

The BMC Kaius 01 Three Bike is BMC's race-purpose gravel platform, built around aerodynamics, compliance management, and geometry refinement for the demands of modern gravel racing. BMC's development work on the Kaius produced a frame with a claimed 7% aerodynamic gain at 40 km/h — meaningful at race pace, where headwinds and sustained flat sections determine outcomes. The Kaius 01 lineup shares a common carbon chassis; the Three brings that engineering to a price point with a complete build spec, including a factory-fitted power meter and carbon wheels.

Aerocore Frame, ICS Cockpit, TCC Compliance

The Kaius 01 Premium Carbon frame uses BMC's Aerocore design, which integrates the bottle cage mounts structurally into the downtube and seat tube profiles. The cages become part of the airflow system rather than hardware bolted onto tubes optimized without them — a distinction that matters when the goal is a coherent aerodynamic package rather than a fast frame with accessories attached. Cable routing is fully internal through BMC's ICS (Integrated Cockpit System) and the RSM01 integrated stem, with stealth routing from the cockpit through the frame eliminating exposed housing. The RSM01 stem is designed for easy stack adjustability, so fit changes don't require a full cockpit teardown. The frame uses a UDH (Universal Derailleur Hanger) dropout, which is forward-compatible with SRAM Transmission drivetrains if you want to change platforms later. TCC (Tuned Compliance Concept) governs the carbon layup decisions throughout the frame and fork — vertical flex engineered into the seatstays and fork legs for compliance on rough terrain, while lateral stiffness at the bottom bracket and head tube preserves power transfer and steering precision. Tire clearance reaches 52mm, significantly wider than most aero gravel frames allow, and the geometry was refined with a longer reach to shift the front wheel forward for improved traction and stability on loose surfaces.

GRX Di2 and 4iiii Power Meter

The drivetrain is Shimano GRX Di2 RX825 — fully wireless electronic 2x shifting with the GRX RX820 crankset. That crankset ships with a 4iiii Precision GEN3+ single-sided power meter factory-fitted. At $5,799, a gravel bike with a calibrated crank-based power meter included from the build is a meaningful specification; most bikes at this level require a separate purchase and installation. The 48/31 chainring combination delivers road-like efficiency at the top end alongside a compact inner ring for climbing, running through a Shimano Ultegra R8101 12-speed 11-34 cassette. Shimano GRX RX820 hydraulic disc brakes handle stopping, with Shimano CL800 160mm Centerlock rotors front and rear.

CG 40 SL Carbon Wheels and Cockpit

The CG 40 SL carbon wheels (40mm deep, 700c, tubeless ready) are BMC's own branded wheelset, developed alongside the Kaius frame rather than sourced from a third party. The 40mm depth provides aerodynamic return on fast flat terrain while remaining manageable in crosswind conditions common on exposed gravel courses. Pirelli Cinturato Gravel H tires at 700x40 run tubeless, a supple 120tpi casing well suited to mixed hard-pack and gravel surfaces. The cockpit pairs the RSM01 integrated stem with BMC's HB D4 03 alloy bar — 125mm drop, 70mm reach, 12-degree flare — giving enough drop for an efficient road-like position and enough flare at the drops for stability on technical descents. The Kaius 01 Premium Carbon D-shaped seatpost with 15mm offset adds compliance at the seat junction and accepts BMC's D-Fender mudguard system. Aerocore carbon bottle cages are included, designed to fit within the Aerocore frame contours. The Fizik Vento Argo X3 on 140mm Kium rails completes the saddle spec.

Available in Stone Grey in six sizes from 47 to 61cm. At $5,799 with a carbon frame built around genuine aerodynamic development, Shimano GRX Di2 wireless electronic shifting, a factory power meter, and BMC's own 40mm carbon wheels, the Kaius 01 Three arrives as a complete race-ready gravel build that doesn't require immediate component upgrades to be competitive.