bmc gravel bike 2021 BMC Kaius 01 Two Gravel Bike

The BMC Kaius 01 Two Bike is built around a single premise: gravel racing is fast, and your bike needs to keep up. Developed in BMC's Impec Lab and drawing aerodynamic architecture directly from the Teammachine R road platform, the Kaius 01 is a race-first gravel machine — narrow where it needs to cut through air, compliant where the terrain demands it, and stiff where power transfer matters. The Two build pairs BMC's premium carbon frame with a 1×13 SRAM Force XPLR drivetrain, an integrated single-sided power meter, BMC's own CG 39 carbon wheels, and a one-piece ICS Carbon Aero cockpit, all at 7.8kg in size 54.

The frame is the story. BMC's AeroCore design shapes the downtube around the presence of water bottles — the profile is sculpted to anticipate the aerodynamic disruption of mounted bottles and reduce it, so the bike is designed to be faster with bottles in place than without them. The Halo Fork takes the same approach at the front end: a wide-crown design that directs airflow away from the wheel and tire while simultaneously creating generous tire clearance up to 44mm. A deep cross-section aero head tube extends the aerodynamic continuity through the front end. The ICS Carbon Aero cockpit — a one-piece full carbon bar and stem unit — continues that logic: a narrow top section for an efficient position in the drops, flaring to a wider width lower down for control on rough descents. The bar runs 135mm of drop, 77mm of reach, and 12.5° of flare, a geometry tuned for gravel racing rather than road criteriums. BMC's Tuned Compliance Concept (TCC) at the Race level handles the ride quality side: the frame's compliance characteristics are engineered to absorb trail chatter and fatigue-inducing vibration without sacrificing the lateral stiffness needed to transfer power cleanly. Race-specific geometry with a longer reach shifts the front axle forward, increasing traction and stability on loose surfaces without making the bike feel sluggish at lower speeds.

Drivetrain is 1×13 SRAM Force XPLR AXS — BMC's choice for this platform reflects gravel racing's shift toward wide-range single-ring setups. The 42T chainring pairs with SRAM's XG-1371 10-46T cassette for a range that covers genuine climbs without the mechanical complexity or weight of a front derailleur. Shifting is wireless via SRAM Force AXS, and the crankset includes an integrated single-sided power meter — a meaningful inclusion at this price point that lets riders train and race with accurate data without adding external hardware. SRAM Force AXS hydraulic disc brakes with SRAM Centerline X 160mm rotors front and rear handle stopping. The CG 39 carbon wheels are BMC's own design: 39mm deep, tubeless-ready, with Star Ratchet engagement hubs and a straightpull spoke design. Pirelli Cinturato Gravel H tires at 40mm mount tubeless from the factory. A Fizik Vento Argo X3 saddle and integrated Aerocore bottle cages complete the build. A computer mount compatible with both Garmin and Wahoo units is included.

Design Benefits

1. AeroCore design + Halo Fork — downtube sculpted to optimize airflow around mounted bottles; wide-crown Halo Fork deflects air away from the front wheel while providing 44mm tire clearance
2. Tuned Compliance Concept (TCC Race) — engineered flex in the frame and fork absorbs sustained vibration from rough surfaces, reducing fatigue over long race distances while maintaining lateral stiffness for power transfer
3. ICS Carbon Aero one-piece cockpit — full carbon bar and stem integration with a narrow top section for an aero position and a wider, flared drop for control at speed on rough terrain
4. 1×13 SRAM Force XPLR AXS — wireless gravel-specific drivetrain with a 42T chainring and 10-46T cassette, wide enough for genuine mountain terrain without the weight or complexity of a double
5. Integrated single-sided power meter — built into the SRAM Force XPLR crankset, providing training and race data without external hardware
6. BMC CG 39 carbon wheels — 39mm deep tubeless-ready carbon rims with Star Ratchet engagement hubs, sized for aero efficiency in gravel race conditions

Final Take

The Kaius 01 Two is a race-focused gravel bike at a competitive price for what it delivers: an aero carbon platform built in the Impec Lab, a 1×13 wireless drivetrain with an integrated power meter, and BMC's own carbon wheelset. At $6,799, it's a significant value on a bike designed to compete at the front of gravel events rather than simply participate in them.