Bicycle wheelset Fulcrum Speed 40 DB 2WF C19 AFS, front HH12 – rear HH12/142 USB

The Fulcrum Speed 40 DB 2WF C19 AFS is a 28-inch wheelset for road cycling and triathlon. The rims are made of carbon, are 40 mm high, and the wheelset weighs 1470 g.

Specifications

• Tyre type: 2-Way Fit (for clincher and tubeless tyres)
• Tyre size: 28″
• Discipline: road / triathlon
• ASTM category: 2
• Weight (front + rear): 1470 g
• Rim material: carbon
• Rim material details: full carbon, “Twill” carbon-fibre finish
• Rim profile height: medium
• Rim height: 40 mm
• Rim width: 26.5 mm
• Inner rim width (channel): 19 mm
• Tyre width: from 23 mm to 50 mm
• Braking system: disc brake
• Braking interface: AFS
• Front axle compatibility: HH12-100
• Rear axle compatibility: HH12-142
• Front wheel spokes: 21, Two-to-one (14 left – 7 right)
• Rear wheel spokes: 21, Two-to-one (7 left – 14 right)
• Spoke material: stainless steel, double-butted
• Spoke profile: round, straight-pull
• Nipples: aluminium
• Front hub: carbon, oversized aluminium flange
• Rear hub: aluminium, oversized aluminium flange
• Bearings: USB ceramic bearings. Adjustable Cup & Cone bearing system
• Other: plasma-treated HG freehub, aluminium axle
• Weight limit (front + rear): 109 kg (cyclist)
• Optional freehub: SHIMANO HG11 (8/9/10/11-speed), Campagnolo N3W or SRAM XDR

Technologies

2-Way Fit (Road): 2-Way Fit technology makes tubeless rims compatible with standard clincher tyres and inner tubes. These road wheels are suitable for a variety of situations. A special recess in the valve area allows the inner tube to be fitted precisely and kept stable inside the tyre. The tubeless tyre valve can also be fitted safely, avoiding air leaks caused by incorrect positioning.

RDB (Rim Dynamic Balance): The weight of the rim joint is balanced by placing an item of similar weight on the exact opposite side. On top models, this is achieved by a special process on the rim section opposite the joint. On entry-level models, Dynamic Balance is achieved using two oversized spokes in the section opposite the joint. The result is a wheel with balanced rotational dynamics.

2:1 Two-to-One: When pedalling, the rotational force on the sprocket slackens the freehub spokes, reducing rim tension. This causes undesirable flex in the whole wheel and a resulting loss of energy. Fulcrum addresses this common cycling problem with its patented 2:1 Two-to-One spoke ratio, doubling the spokes in critical areas.

MoMag: A magnet and an ingenious idea led to the patent for the proven “Mounting Magnet” system, or MoMag.

Traceability: Fulcrum products are traceable. Do not remove the small label attached to a product: if a production-batch defect is confirmed, it helps identify the required component or wheel.

Anti-rotation system: This system takes spoking performance to a new level for road, triathlon and mountain-bike wheels. Fulcrum engineers redesigned the spokes and hub bodies to create a solid, fixed unit. The spokes retain their initial tension, keeping the wheel responsive and centred. They also remain in the position established through wind-tunnel testing for improved aerodynamic performance.

AFS (Axial Fixing System): This is Fulcrum’s system for attaching a disc brake to the hub. The larger supporting surface of the fastening mechanism, compared with familiar standard solutions, increases structural rigidity for more precise and powerful braking.

Wide Rim Tech: In response to the demands of competitive cycling, Fulcrum’s R&D department developed rims approximately 4 mm or more wider than previous versions. They provide a suitable base for the currently popular 25–28 mm tyres and offer stability, good handling and improved comfort.

Cup & Cone: Cup-and-cone bearings differ from standard cartridge bearings because they operate in alignment with the forces involved: weight and pressure from the frame. The bearings run in a race positioned directly opposite these forces. The adjustment ring lets you preload the bearing, eliminate side-to-side play and achieve optimal adjustment once the wheel is mounted in the frame.

Full Carbon Rim Technology: Fulcrum full-carbon rims use combinations of different fibres developed in the laboratory, including UD and the 90-degree 3K fibre used in top-range models. They are made with a special HTG (high transition grade) resin, whose glass-transition temperature is higher than that of other fibres used in the bicycle industry. This provides exceptional braking performance.

Plasma freehub: Plasma treatment makes aluminium especially hard and resistant to surface abrasion and wear. This allows the material thickness and weight to be reduced while maintaining service life and reliability.

Oversize flange: The oversize flange was developed to transfer power to the ground with minimal loss and stiffen the wheel where needed, without adding weight through extra spokes or structures. It increases spoke bracing angle and allows shorter spokes. Doubling the spokes creates a balanced system that transmits torque effectively.

Disc-specific rim: Compatible only with disc brakes.

USB (Ultra Smooth Bearings) ceramic bearings: Fulcrum hubs are known for smooth operation and reliability. Their designs are developed by the R&D department, with close attention to detail. USB ceramic bearings further improve the smoothness of road and triathlon wheels while reducing weight and maintenance requirements.

Monoblock hub for disc: The rear hub of a high-quality disc-brake wheel presents a technical challenge. Fulcrum’s R&D department chose to position the Two-to-One system’s oversized flange on the sprocket side. To reduce braking-power losses caused by flex and torque in the connector between the two sides of the hub, a one-piece design with internal stiffening ribs was developed.

Carbon hubs: To reduce weight and use advanced technical solutions, the R&D department developed a seamless carbon hub. The selected fibre is woven at 90 degrees to improve the balance of pedalling torque.

DRSC (Directional Rim-Spoke Coupling): An exclusive rim-and-spoke coupling system. It allows the rim, spokes, nipples and hub to align correctly, with the same tension value throughout.

Undrilled rim bed: With no holes in the bridge connector, the rim is uniform throughout and has no stress-prone critical areas. This reduces weight, extends rim life, improves fatigue resistance and allows greater spoke tension. The increased stiffness improves responsiveness and acceleration.