HD SDM Aluminium Mast Extension (U-Pin) 30
Dominate Every Session with the Revolutionary HD SDM Aluminium Mast Extension (U-Pin) 30
Maximum power with minimum effort – that's what the Unifiber HD SDM Aluminium Mast Extension delivers to serious windsurfers. This revolutionary extension transforms your rigging experience with its advanced 3-roll pulley system that cuts downhauling effort in half, even with high-tension race sails.
Engineered for the performance windsurfer, this extension features a reinforced high-quality polyamide base compatible with all racing sails, ensuring rock-solid stability when you need it most. The lightweight aluminium construction shaves precious grams off your rig without sacrificing an ounce of strength – giving you the competitive edge whether you're slashing through choppy water or flying across flat conditions.
The game-changing open-and-slide collar system lets you adjust functional length with just one hand – meaning faster rigging and more time on the water. With its barefoot-friendly design and pre-stretched polyester rope, this extension delivers professional-grade performance with everyday usability.
Backed by Unifiber's industry-leading 2-year warranty (1 year unconditional + 1 year conditional), this extension represents the perfect marriage of innovation and reliability.
Join the ranks of windsurfers who refuse to compromise – upgrade to the HD SDM Aluminium Mast Extension and experience the difference that professional-grade equipment makes.
Also available in 45cm
- Mast compatibility : SDM
- Wall Thickness : 3 mm
- Max Insertion :
- Downhaul Ration : 6:1 - 2 pulleys
- Extension range : 5 - 30 cm
- Pulley angle : 0 Degrees
- Pulley diameter :17 mm
- Pre-stretched Polyester 4.0mm
- Rope compatibility :3.8mm - 4.0mm
- Rinse your extension thoroughly after each use to remove corrosive salt and abrasive sand.
- Keep sliding components clean and sand-free to prevent wear.
- Replace your downhaul line at least once per season and apply silicone lubricant to cleats for better grip.
- Before hitting the water, always inspect for cracks, corrosion, or worn components like pulleys and pins.
- Store your extension completely dry in a protective bag away from UV exposure, and never leave it inside the mast during storage to prevent corrosion.
What does features 1 year unconditional + 1-year conditional warranty cover ?
At Unifiber, we're confident in the quality of our gear and stand behind everything we make.
Here's how our warranty works:
- First year: Your product is completely covered - simple as that. We've got your back so you can focus on enjoying your time on the water.
- Second year: We continue to support you against any manufacturing defects because we believe in building gear that lasts.
- To make things hassle-free, just keep your proof of purchase handy when you need us., we're confident in the quality of our gear and stand behind everything we make.
Learn More
Choosing the right windsurf mast extension can make a big difference in your rigging experience and overall performance on the water.
From pulley systems to downhaul ratios, every detail plays a role in ease of use and durability.
In this FAQ, we’ll answer the most common questions to help you find the perfect extension for your setup.
1. What type of rope should I use for a boom or mast base extension?
- It’s best to use Dyneema or Spectra rope, as they are highly durable and have low stretch. A diameter of 4–5 mm is ideal to minimize friction while ensuring a good grip.
2. What do I need to know about mast extension insertion length?
- Because of the tapered shape of an SDM mast, there's a limit to how far one can insert the mast extension. This value relates to the total length of your extension tube, not to confuse with the range settings.
- A maximum 45 cm insertion length means that most 32cm mast extensions can be fully inserted into the mast. A maximum 60 cm insertion length means that most 46cm mast extension can be fully inserted.
- In case a non Unifiber brand extension does not fit, as an alternative solution the mast extension end cap can be removed without problem.
3. What is the downhaul ratio?
- The downhaul ratio refers to the mechanical advantage provided by the pulley system.
- For example, a 3:1 system means that for every unit of force applied, the tension on the sail is multiplied by three. Modern extensions often have 4:1 or even 6:1 systems, making downhauling easier with less effort.
4. Why is the pulley angle important?
The pulley alignment affects how easy it is to downhaul the sail. Proper alignment between the extension’s pulleys and the sail’s pulleys reduces friction and makes rigging easier. If the pulleys are misaligned, the rope can wear out faster, and downhauling becomes more difficult.
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