Armstrong Board Shim w/ 30mm Screws

The Armstrong Board Shim w/ 30mm Screws is a foil-tuning accessory from Armstrong Foils that allows riders to adjust the mast angle relative to their board. The shim sits between the mast base and the board's mounting plate, tilting the mast forward or aft by a set number of degrees. This changes the rider's foot pressure balance and overall foil feel without requiring a different mast or board. It ships with the longer screws needed to accommodate the added thickness of the shim between components.

• Available angles: 1° and 2°
• Included hardware: 2× 30mm M6 screws, 2× 30mm M7 screws
• Price: $44.99 USD (same for both degree options)

The Board Shim is aimed at intermediate to advanced foil riders who want to fine-tune their setup beyond what shimming techniques or stance adjustments alone can achieve. Changing the mast angle by even one or two degrees shifts where the rider needs to apply pressure along the board, which can make a noticeable difference in pumping efficiency, stability at speed, or how the foil initiates turns.

Riders using Armstrong boards with Armstrong masts may find this useful when dialing in a new front wing or adapting to different conditions. It can also help riders who mount an Armstrong mast into a third-party board where the stock mast-box angle doesn't match their preferred geometry. Because the shim comes with both M6 and M7 screws in the 30mm length, it covers the two common Armstrong mounting-bolt sizes without requiring a separate hardware purchase.

Within Armstrong's accessory catalog, the Board Shim sits alongside other mounting hardware such as screw sets, mast shims, and tuttle-box adapters. It is a straightforward, single-purpose accessory rather than part of a broader product line with multiple generations. Armstrong sells both the shim bundled with 30mm screws (this product) and a standalone shim without hardware for riders who already have the correct longer bolts. For riders exploring mast-angle adjustments on other brands, similar wedge shims are available from companies like Slingshot and Axis, though cross-brand compatibility depends on matching the mounting-hole pattern and bolt sizes to the specific board and mast combination.