HD RDM Carbon Mast Extension (U-Pin) 30
HD RDM Carbon Mast Extension (U-Pin)
Ultra-light. Rock-solid. Built to perform.
Dial in your rig with precision and feel the power flow. The Unifiber HD RDM Carbon Mast Extension brings effortless tuning and rugged performance together in a lightweight carbon build that serious windsurfers rely on—day in, day out.
Whether you’re chasing cleaner lines or chasing the wind, this extension delivers stiffness where it counts, helping you transfer every ounce of energy straight to your board. It’s fast, tough, and intuitive.
Why riders love it
- Lightning-fast rigging with U-Pin simplicity
- Lightweight carbon construction means less swing weight
- Superior stiffness boosts response and acceleration
- Reinforced base built to take a beating
- Corrosion-resistant hardware for season-after-season use
Whether you’re racing or just riding hard, this extension delivers the control and confidence to go full send.
Less rig hassle. More water time. Go HD.
- Mast compatibility : RDM
- Wall Thickness : 2 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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