Lewmar 29925039BK Sailboat Block
Lewmar 29925039BK Sailboat Block Product Description
Imagine trimming your sails with lightning precision during a competitive race or a leisurely coastal cruise—every pull smoother, every adjustment effortless. The Lewmar Synchro fiddle block transforms that vision into reality, blending cutting-edge engineering with practical sailor needs. Its fiddle design, paired with an integral cam cleat, makes it a go-to for handling moderate loads where quick line control is essential. Unlike basic blocks that bind under pressure, this one slashes friction through smart geometry and a free-spinning bearing, delivering up to 40% better efficiency on systems like mainsheets.
Precision Engineering for Peak Performance
At the heart of this black fiddle block lies a self-aligning head that keeps everything in perfect sync with your rope's path, no matter the angle. The 50mm sheave diameter accommodates 10mm lines effortlessly, while the single pulley setup with becket ensures seamless cascading in purchase systems. Glass fiber reinforced cheeks add stiffness to fend off line wedging, even in choppy conditions, and a stainless steel strap boosts durability against saltwater corrosion and UV exposure.
The tool-free sliding swivel locking mechanism on the shackle mount lets you position it exactly where needed—fast setup, no tools required. Supporting a 990-pound working load limit, it's built for the demands of mid-sized sailboats, from dinghies to cruisers, where reliability trumps bulk.
Real-World Advantages for Serious Sailors
- Friction-Free Operation: The free-spin bearing and optimized geometry mean less effort to sheet in, preserving your energy for steering and tactics.
- Superior Rope Longevity: Smooth power transfer reduces heat buildup and chafe, extending the life of your favorite sheets.
- Versatile Cleating: The integral cam cleat grips securely in any direction without ratcheting, ideal for fine-tuning under load.
- Rugged Build: Non-wedging cheeks and reinforced materials stand up to years of abuse, backed by a solid warranty for peace of mind.
- Effortless Maintenance: Open design allows quick inspections and lubrication, keeping it race-ready with minimal downtime.
Ideal Setups and Sailing Scenarios
This swivel shackle-mounted block shines in mainsheet travelers, vang tackles, or spinnaker sheets where space is tight but control is critical. Racers love its speed for rapid trims during tacks and gybes, while cruisers appreciate the low-maintenance reliability on extended passages. Pair it with a becket for double-purchase systems, multiplying your mechanical advantage without adding weight. In black finish, it blends sleekly with modern deck hardware, resisting grime for a polished look.
Whether you're optimizing a J/24 for club racing or rigging a Beneteau for bluewater adventures, this block elevates your setup's efficiency, helping you sail faster and smarter.
Pro Tips for Long-Lasting Performance
Keep it performing like new by rinsing with fresh water after every sail to flush salt. A drop of marine-grade lubricant on the bearing yearly prevents binding. Inspect the cam cleat for wear during haul-outs—replace if teeth dull. Avoid shock-loading by easing lines gradually, maximizing that impressive load capacity. Sailors who've run these blocks season after season swear by their "set it and forget it" vibe.
Frequently Asked Questions
What makes this fiddle block more efficient than standard blocks?
Its scientifically optimized geometry, free-spin bearing, and self-aligning head cut friction by up to 40%, especially on mainsheet systems, for smoother operation and less rope wear.
Can this block handle 10mm lines effectively?
Yes, the 50mm sheave is perfectly sized for 10mm diameter lines, providing optimal grip and minimal drag for reliable performance.
Is the cam cleat suitable for holding loads in both directions?
Absolutely—the non-ratcheting integral cam cleat secures lines securely from any direction, great for dynamic sailing maneuvers.
What mounting options does it offer?
It features a swivel shackle mount with a tool-free sliding locking mechanism, allowing flexible positioning without tools.
How durable is the construction for marine use?
Glass fiber reinforced cheeks and a stainless steel strap provide exceptional strength and resistance to wedging, corrosion, and UV damage.
Does it include a becket for multi-purchase systems?
Yes, the built-in becket makes it easy to create efficient purchase systems, boosting mechanical advantage on the water.
Lewmar’s Synchro blocks are engineered for speed, efficiency and superior handling. We use a combination of scientifically optimized block geometry, a Free-Spin bearing and self-aligning head to reduce friction and increase efficiency by up to 40 Percent over budget blocks on mainsheet systems. Each component is perfectly synchronized with the movement of the rope, providing you with an easier, smoother transfer of power from deck to sail and less wear on your rope.
Lewmar 29925039BK Attributes
- Type: Fiddle Block
- Number Of Pulley: 1
- Working Load Limit: 990 Pound
- Line Diameter: 10 Millimeter
- Sheave Diameter: 50 Millimeter
- Cleat Type: Integral Cam Cleat
- Ratchet And Direction: Non Ratcheting Any Direction
- With Becket: Yes
- Color: Black
- Material: Glass Fiber Reinforced Cheek
- Mounting Type: Swivel Shackle Mount
Lewmar 29925039BK Features & Benefits
- Stainless Steel Strap For Improved Strength And Longer Service Life
- Stiff Glass Fiber Reinforced Cheeks To Prevent Lines From Wedging
- Innovative Design With Tool-Free Sliding Swivel Locking Mechanism
- Easy Maintenance
- Limited 3 Year Warranty
Lewmar 29925039BK Warranties
Frequently Asked Questions (FAQ) About Lewmar 29925039BK Sailboat Block
Who is the Lewmar?What is the type of the product?
What is the material of Lewmar 29925039BK Sailboat Block?
What is the mounting type of the product?
What's the color of Lewmar 29925039BK Sailboat Block?
Who is the Lewmar?
What is the type of the product?
What is the material of Lewmar 29925039BK Sailboat Block?
What is the mounting type of the product?
What's the color of Lewmar 29925039BK Sailboat Block?
Save $27 when you buy the Lewmar 29925039BK Sailboat Block for only $76 from NVN Marine! Same day shipping before 3pm.
Lewmar 29925039BK Sailboat Block Videos
Lewmar 29925039BK Sailboat Block Technical Specifications
| Type: | |
|---|---|
| Vendor: |
Lewmar |
| Weight: |
0.44 lb |
Lewmar 29925039BK Sailboat Block User Reviews
Lewmar 29925039BK Sailboat Block Shipping & Return
| Shipping Weight: |
0.44 lb |
|---|---|
| Box Sizes: |
4.00 (h) x 5.00 (w) x 10.00 (l) |
| Cubic Feet: |
200.0 |
| Returnable: |
Yes |
For detailed shipping policy please check our Shipping Policy and you can find our Return and Refund Policy here.



