G10 vs Carbon

Separating myth from hydrodynamic reality when it comes to weed fin performance.

Material reality, not marketing

When machining from a pre-cured block of material, or injecting a homogeneous material into a mould, you are constrained by the mechanical properties of that material.

With G10, fibres run at 90 degrees in an even distribution. Along the fibres the product is stiffer, at 45 degrees it is more flexible. Stiffness and flex are therefore controlled by the 3D shape, including rake, fibre alignment, thickness and chord distribution.

Flex, torsion and upright fins

With upright fins there is some advantage in allowing the fin to flex along the blade, whilst remaining torsionally rigid. This ensures the angle of attack remains constant over the blade length as it flexes.

When flexed, the blade resembles a J foil, providing a degree of vertical lift and helping stabilise board trim, especially in lighter wind when the fin is loaded.

Flex is only useful when it does not introduce twist.

Rake, twist and spinout

When a blade has rake, flex introduces twist toward the tip. As the blade bends, the trailing edge shifts more windward than the leading edge, known as geometric twist.

This lowers the angle of attack toward the tip, reduces lift, overloads the base and increases the risk of sudden spinout in gusts. Unlike sails, twist is not useful in performance windsurfing fins.

Why Tribal weed fins are stiff

Raked fins must be stiff along the blade and torsionally rigid. The Tribal G10 range is designed to be stiff for this reason.

Thickness does not mean slow. Real-world results prove otherwise.

Carbon vs G10, the real trade-offs

• Durability: Carbon is easily damaged by impact or abrasion. G10 is far more tolerant.
• Stiffness: With correct thickness, G10 is already stiffer than required.
• Weight: Carbon is lighter, but fin weight has little influence on board trim.

Conclusion: For weed fins, carbon offers no performance advantage and compromises durability, cost and reliability.