STREAMLINED SDM EXTENSION V8 EUR

The Streamlined SDM (Standard Diameter Mast) Extension is often called the "Rolls Royce" of extensions. While most brands moved toward plastic parts to save costs, Streamlined stuck to a precision-engineered, all-metal design that has remained virtually unchanged for decades because it simply works.

Here is the breakdown of the SDM version (designed for standard 48mm diameter masts):

1. The "Big Power" Pulley System

The standout feature of any Streamlined extension is the Power-Haul pulley block.

• Large Diameter Pulleys: They use much larger wheels than standard extensions, which significantly reduces friction.

• Alignment: The pulleys are oriented to match the tack pulley on 99% of modern sails. This creates a "straight-line" downhaul, making it much easier to tension large, high-cambered sails by hand.

• No Crossing Lines: The design prevents the rope from overlapping, which is the main cause of friction and rope wear.

2. Construction & Durability

3. US Cup vs. Euro Pin

Since you previously asked about the US Cup, the Streamlined SDM extension is available in both formats:

• US Cup version: Features the "Pin" at the bottom that clicks into the "Cup" of your mast base.

• Euro Pin version: Features the "Cup" (hole) at the bottom that clicks onto the "Pin" of a standard base.

4. Why SDM users love it

• Stiffness: Because it’s made of heavy-duty aluminum, it doesn't flex under the massive downhaul loads of racing or freeride sails.

• Longevity: It is common to see windsurfers using the same Streamlined extension they bought 15 years ago. Every single part (pulleys, pins, tubes) is replaceable.

• The Cleat: The integrated cleat is machined into the aluminum, meaning it won't "slip" or wear down like plastic cleats found on cheaper models.

Pro Tip: The "Marlow" Rope

Streamlined extensions usually come equipped with Marlow Formuline rope. This is the stiffest, strongest, and slickest rope in the world. If you ever replace the rope, only use Formuline to maintain that effortless downhaul feel.