The Dynafiber RDM Alu Extension is the fundamental aluminum workhorse of the Dynafiber range. While we previously discussed the high-end "Inox" version (which uses a stainless steel base), the standard Alu RDM is a more streamlined, lightweight, and cost-effective option for everyday windsurfing.
For the 2025/2026 season, this extension is defined by its reliability and simple, effective design.
T8 Aluminum Tubing: Unlike budget "6061" aluminum, the Dynafiber uses T8 aluminum, which is significantly stiffer and harder. This prevents the extension from bending or "curving" inside the mast when you apply heavy downhaul tension.
Internal Reinforcement: Most 2025 models include an internal reinforcement insert at the bottom of the tube. This strengthens the area where the tube meets the pulley block—the highest-stress point of any extension.
Steel Button & Pins: While the pulley block itself is a high-density composite on this standard version, the release button and adjustment pins are made of stainless steel to ensure they don't snap or jam with sand.
| Feature | Details |
| Diameter | RDM (Reduced Diameter Mast) only. |
| Lengths | Available in 32 cm and 48 cm. |
| Adjustment | 2 cm steps (standard) for precise sail tuning. |
| Connection | Euro Pin (Universal Pin) - compatible with all modern bases. |
| Pulleys | 3 high-diameter pulleys (easier downhauling than 2-pulley systems). |
| Weight | Approx. 600g to 650g (32cm), making it very light for aluminum. |
It is easy to confuse the two. Here is the main difference:
Alu Standard (This model): Uses a high-strength reinforced plastic/composite base. It is lighter and cheaper, perfect for wave sailing and freeriding where you want to keep the weight down.
Alu Inox: Uses a cast stainless steel base. It is heavier and more expensive, designed for the extreme loads of professional racing or for maximum longevity in salty, harsh environments.
Price-to-Performance: It is one of the most affordable ways to get a T8 aluminum extension that won't fail in the surf.
Simplicity: The three-pulley system is intuitive to thread and offers a good mechanical advantage, meaning you won't need a winch for most wave and freeride sails.
Low Profile: The "Minimum Extension" setting is very low (approx. 4 cm), allowing you to get the foot of your sail right down to the board's deck.