Description
Ronstan Series 20 Triple Ball Bearing Block | Boat Supply Store
This Ronstan Series 20 Ball Bearing Block is engineered for exceptional efficiency in demanding sail control applications, offering a remarkable 400kg (880lbs) Working Load Limit (MWL) with minimal friction. Its 20mm (3/4") Acetal sheaves, supported by stainless steel ball bearings, ensure smooth operation under significant loads, crucial for precise mainsail or jib sheeting on dinghies and small keelboats. Constructed with UV stabilized Acetal sheaves and reinforced Nylon cheeks, this block provides robust durability for extended use in harsh marine environments.
Key Features
- Superior Low Friction performance minimizes effort for sail trim.
- High Load Capacity handles significant static and dynamic loads up to 400kg MWL.
- Lightweight Construction reduces overall rigging weight.
- Precision Molded Acetal Sheaves ensure smooth rope passage.
- Durable Stainless Steel Ball Bearings provide long-lasting, low-friction rotation.
- Versatile 2-Axis Head allows for fixation at 0° or 90° for optimal lead angles.
- UV Stabilized Acetal Sheave resists degradation from sun exposure.
- Impact and UV Resistant Cheeks constructed from fiber-reinforced Nylon.
Specifications
| Product Specifications | |
|---|---|
| Sheave Ø | 20mm (3/4") |
| Max. Rope Ø | 6mm (1/4") |
| Pin Diameter | 4mm (5/32") |
| Working Load Limit (MWL) | 400kg (880lbs) |
| Breaking Load (BL) | 850kg (1,870lbs) |
| Weight | 64g (2.3oz) |
| Sheave Material | UV stabilized Acetal |
| Ball Bearing Material | Stainless Steel |
| Cheek Material | Fiber reinforced Nylon |
| Head Fitting Material | Grade 316 Stainless Steel |
| Load Strap Material | Grade 316 Stainless Steel |
| Number of Sheaves | Triple |
Who This Is For
Sailors of dinghies and small keelboats requiring high-performance, low-friction control line management, including those involved in racing or performance cruising. This block is ideal for optimizing trim on boats up to approximately 25 feet.
How It Compares
| Feature | Ronstan Series 20 Triple Ball Bearing Block | Competitor |
|---|---|---|
| Sheave Ø | 20mm (3/4") | — |
| Max. Rope Ø | 6mm (1/4") | — |
| M.W.L. | 400kg (880lbs) | — |
| Number of Sheaves | Triple | Single, Single |
| Head Type | 2-Axis Shackle | Swivel, Swivel |
Common Concerns Answered
Are replacement parts readily available for this block?
While most Ronstan components are designed for longevity, occasional difficulties in sourcing specific replacement parts for older models have been noted. We recommend maintaining your block according to manufacturer guidelines to maximize its lifespan and ensure availability of standard wear items.
Why is this block more expensive than basic options?
The higher price point reflects the advanced engineering and materials, including precision stainless steel ball bearings and UV-stabilized Acetal sheaves, which deliver significantly lower friction and superior durability compared to non-ball bearing blocks. This investment translates to enhanced performance and a longer service life for demanding sailing applications.
Is this block suitable for heavy-duty offshore use?
The Ronstan Series 20 block is optimized for dinghies and small keelboats with a 400kg MWL. For larger vessels or more extreme offshore conditions, consider Ronstan's larger series blocks which offer higher load ratings and different construction materials.
Frequently Asked Questions
What is the maximum rope diameter this Ronstan block can handle?
The Ronstan Series 20 Ball Bearing Block is designed to accommodate a maximum rope diameter of 6mm (1/4").
What is the working load limit (MWL) for the Ronstan Series 20 Ball Bearing Block?
The working load limit (MWL) for this Ronstan Series 20 Triple Block is 400kg (880lbs).
Can the head of this Ronstan block be fixed at different angles?
Yes, the 2-axis shackle head on this Ronstan block can be fixed at either 0° or 90°, allowing for precise control line routing.
What type of ball bearings does the Ronstan Series 20 block use?
The Ronstan Series 20 Ball Bearing Block utilizes high-performance stainless steel ball bearings for low friction and durability.
What are the typical applications for a Ronstan Series 20 Triple Block?
Typical applications include mainsail halyards, jib sheets, control lines, and vangs on dinghies, sportboats, and small keelboats where efficient and reliable line management is critical.
