Windsurf Booms

Modular Boom Concept : CONFIGURE ME

In 2019, Unifiber revolutionized the windsurfing world with the Modular Boom Concept. Instead of seeing a boom as a single product, we broke it down into three interchangeable parts: boomhead, body, and tail. This modular approach offers unique advantages:

1. Cost-Effective Repairs: If a part breaks, just replace it—no need to buy a whole new boom. This saves you money and reduces environmental waste.
2. Flexible Configurations: Need two booms? Buy one and a half! For example, if you own a 190-240 ELITE boom and upgrade to a bigger sail, simply add a 220-270 tail to extend its range. Or, use the same boomhead across multiple booms.
3. Customizable Performance: Mix and match parts to suit your style. Pair the durability of an HD boom body with the lightweight performance of an ELITE tail for a personalized setup.
4. Eco-Friendly Shipping: Traditional booms are bulky and inefficient to ship. By disassembling the boomhead, body, and tail, we optimize space, reducing shipping costs and environmental impact.

The Boomhead

The Boomhead: Where Precision Meets Performance

The boomhead is the heart of your rig, transmitting all forces—wind, water shocks, and your movements—through the mast. A poorly designed boomhead can compromise even the best boom tubes.

At Unifiber, we spent hundreds of R&D hours perfecting the boomhead. Here’s what makes ours stand out:

• Adaptive Fit: Instead of being overly stiff (which can damage your mast), our boomhead molds to the mast’s shape. This ensures even force distribution, protecting your mast and enhancing your control.
• Direct Feedback: With no play, you’ll feel every force acting on your gear, giving you precise control and confidence in any condition.

Boom Grip Diameter

The boom tube diameter directly influences structural rigidity and ergonomic factors. Larger diameter tubes increase the second moment of area, resulting in superior torsional stiffness and enhanced performance characteristics. However, this presents an inverse relationship with grip ergonomics - larger diameters increase forearm muscle fatigue due to greater hand span requirements and elevated grip force demands.

The grip cross-section geometry significantly affects both mechanical properties and user interface dynamics. While a round grip provides uniform radial stiffness distribution, the V-grip design optimizes horizontal plane rigidity. This horizontal stiffness is crucial as it aligns with both the primary force vector of sail drive and the perpendicular pumping force application. The Oval/V-grip configuration in modern carbon composite booms represents an engineered compromise between mechanical efficiency and biomechanical requirements, offering optimal stiffness-to-comfort ratios in the critical load directions.

Narrow or Wide Tail

The boom tail width becomes a critical parameter when scaling up sail dimensions, particularly for sails ≥6.5m².

The relationship between tail width and sail performance manifests through profile integrity maintenance under varying outhaul tension conditions.

Wide tail configurations provide these key advantages:

• Maintain proper sail profile geometry under reduced outhaul tension scenarios
• Preserve designed camber distribution in light wind conditions
• Support optimal aerodynamic efficiency
• Prevent profile deformation that could compromise sail structural integrity

Conversely, narrow tail designs when paired with larger sail areas can:

• Induce undesired profile distortion
• Create sail shape constraints that reduce performance
• Generate localized stress concentrations affecting sail longevity
• Compromise the designed draft position

Modern wave sails are also designed to have quite a deep profile, so it is wise to consider tail width on smaller booms too.

Boom Body Shape

The traditional "regular" boom shape dates back to when booms were made from two separate arms. Its main advantage is a minimal bend radius, making it easier to manufacture from materials like aluminum or wood. However, it forces the front hand (mast hand) into a slightly bent wrist position.

With the rise of monocoque booms—now the standard—the "C" shape became popular. This design offers ergonomic benefits, allowing the lead arm to maintain a more natural wrist position. It improves comfort not only during straight-line sailing but also for gybing and other maneuvers.

Today, the regular shape is outdated, and most booms follow the "C" shape.

However, variations exist—larger booms often adopt a hybrid shape between "C" and regular, as the natural hand position shifts further from the mast.

Inside tail or outside tail

There are two main options for the boom tail:

A larger diameter tail that goes outside the boom body, or a smaller diameter tail that goes inside.

• Tail Inside – A smaller diameter tail slides inside the boom body. This design allows the length adjustment lock to be positioned at the end of the boom body, making adjustments simple. However, since the tail is narrower, it is less stiff.
• Tail Outside – A larger diameter tail fits over the boom body, increasing stiffness. The downside is that aligning the holes for the length adjustment lock can sometimes be tricky.

For shorter sized booms the tail outside option is not offered, as the tail would interfere with the backhand during normal sailing

Boom Tail System

For quick rigging, the loop-loop-go (loop-to-loop) option is most convenient. This is the best choice for medium-sized and smaller sails, helping you get rigged and out on the water quickly!

The pulley option is ideal for booms with an adjustable outhaul system, making it a great feature for bigger sails and racing.

Boom Ajustement Setting

Most windsurf sails quote an outhaul setting The boom length setting should match the required range, but keep in mind that different sail manufacturers may have slight variations in their recommended measurements.

The actual setting also depends on conditions, boom height, and other factors.

• Using a boom at or near its minimum length increases stiffness, improving rig performance. In contrast, extending a boom closer to its maximum range reduces stiffness.
  
• For this reason, most Unifiber aluminium booms extend up to 50cm, while the inherently stiffer Unifiber carbon booms can extend up to 60cm.