Armstrong Alloy System Mast Bottom Bracket

The Armstrong Alloy System Mast Bottom Bracket is a machined connection component that joins the Alloy System mast to the fuselage. Produced by Armstrong Foils as part of their modular Alloy System platform, this bracket is CNC-machined from 7075 aluminium alloy — an aerospace-grade material chosen for its high strength in the load-concentrated junction between mast and fuselage. The rest of the Alloy System mast vertical uses 6061 aluminium, but Armstrong selected the stronger 7075 grade specifically for the top plate and bottom bracket where stress is greatest.

Armstrong developed the bottom bracket's geometry in collaboration with SailGP design consultants. The connection uses a press-fit mechanism: as the fastening hardware is tightened, the bracket seats into the fuselage with tight tolerances, creating a clean, snug interface. Hardware is sold separately — the Alloy System uses custom titanium M7 and M8 x 1.25 screws at the mast-to-fuselage junction, paired with 316L stainless steel fasteners elsewhere in the assembly.

• Material: Machined 7075 aluminium alloy
• Connection type: Press-fit mast-to-fuselage interface
• Hardware included: No (sold separately)
• System compatibility: Armstrong Alloy System
• Price: $99.99 USD

This bracket is a replacement or spare part for riders already on the Armstrong Alloy System. If your existing bottom bracket has sustained damage from impact, corrosion, or repeated assembly wear, this is the direct factory replacement. It's also relevant for riders building up an Alloy System mast from individual components rather than purchasing the complete mast assembly.

Because the Alloy System is designed to serve riders from beginner through advanced across wing foiling, surf foiling, and other foil disciplines, the bottom bracket itself is discipline-agnostic — it functions identically regardless of what front wing or stabilizer is mounted. Armstrong's foil attachment points on the Alloy fuselage share the same hexagonal interface as their carbon A+ System, so riders switching between alloy and carbon mast setups use the same wings.

The bottom bracket sits within Armstrong's Alloy System component lineup alongside the Alloy Mast (available in 58 cm, 72 cm, and 85 cm lengths), the Alloy Fuselage, the Mast Top Plate, and the Alloy Bottom Bracket Hardware Set. Purchasing the complete Alloy Mast assembly includes the bracket pre-installed, so this standalone listing exists primarily as a service part.

Armstrong's product line splits into two mast platforms: the carbon A+ System at the performance end and the Alloy System as a more accessible, durable option. The Alloy System is positioned not as a budget compromise but as a robust alternative — Armstrong emphasizes that section shape, chord, and taper matter more than material alone for most riders. For those already committed to the Alloy platform, stocking a spare bottom bracket is a practical way to minimize downtime from equipment wear.