Description
Ronstan Series 55 Ratchet Block | Boat Supply Store
Control extreme loads and fine-tune sail trim with the Ronstan Series 55 Ratchet Orbit Block™, engineered for precision and robust performance. This block offers up to 21:1 holding power thanks to its Generation 2 sheave geometry, significantly reducing winch effort on mainsheets or spinnaker sheets. The 55mm sheave diameter and capacity for 10mm rope accommodate a broad range of line sizes, making it ideal for sportsboats and small keelboats navigating choppy conditions on Galveston Bay.
Key Features
- Dual Ratchet Modes: Seamlessly switch between automatic and manual engagement for unparalleled sheet control.
- Exceptional Holding Power: Achieve up to 21:1 holding power, minimizing winch effort and fatigue.
- Swivel Shackle Head: Ensures unlimited block rotation, preventing line twisting and optimizing block alignment.
- High-Performance Cleating: Delivers secure and reliable sheet management under load.
- Durable Construction: Features a toughened, glass fiber-reinforced Nylon frame and cheeks for longevity.
- Hard Anodised Sheave: The aluminium sheave provides a smooth, low-friction surface for efficient line passage.
- Grade 316 Stainless Steel: The head fitting is constructed from marine-grade stainless steel for superior corrosion resistance.
- Versatile Applications: Suitable for mainsheets, spinnaker sheets, halyards, vangs, and backstays on smaller craft.
Specifications
| Product Specifications | |
|---|---|
| Sheave Ø | 55mm (2") |
| Max. Rope Ø | 10mm (1/2") |
| M.W.L. | 250kg (550lbs) |
| B.L. | 650kg (1,430lbs) |
| Weight | 82g (2.9oz) |
| Holding Power | Up to 21:1 |
| Ratchet Engagement | Auto & Manual |
| Head Fitting | Swivel Shackle |
| Frame Material | Toughened, glass fiber reinforced Nylon |
| Sheave Material | Hard anodised Aluminium |
| Head Fitting Material | Grade 316 stainless steel |
Who This Is For
Sailors on dinghies, sportsboats, and small keel boats up to 8m (26') requiring high-performance, adaptable ratchet blocks for critical control lines. This block is designed for those who demand precision and reliability in sheet handling across various sailing disciplines.
How It Compares
| Feature | Ronstan Series 55 Ratchet Block | Competitor |
|---|---|---|
| Holding Power | Up to 21:1 | Harken 163 Carbo Ratchomatic Block - Up to 10:1, Lewmar Synapse Ratchet Block 50mm - Up to 18:1 |
| Ratchet Modes | Auto & Manual | Harken 163 Carbo Ratchomatic Block - Auto Only, Lewmar Synapse Ratchet Block 50mm - Auto Only |
| Sheave Diameter | 55mm | Harken 163 Carbo Ratchomatic Block - 57mm, Lewmar Synapse Ratchet Block 50mm - 50mm |
| Max. Rope Diameter | 10mm | Harken 163 Carbo Ratchomatic Block - 10mm, Lewmar Synapse Ratchet Block 50mm - 10mm |
| Working Load Limit (WLL) | 250kg | Harken 163 Carbo Ratchomatic Block - 220kg, Lewmar Synapse Ratchet Block 50mm - 200kg |
| Weight | 82g | Harken 163 Carbo Ratchomatic Block - 78g, Lewmar Synapse Ratchet Block 50mm - 75g |
Common Concerns Answered
Is the dual mode feature difficult to operate?
While the dual auto/manual engagement modes offer advanced functionality, users find them generally intuitive after a brief understanding of their operation, providing significant control benefits once mastered.
Is this block too expensive for casual sailing?
The Ronstan Series 55 Ratchet Orbit Block™ represents a significant investment, justified by its superior holding power, dual-mode versatility, and durable construction, making it ideal for serious racers and performance cruisers who demand the highest level of equipment.
Why does this block cost more than a basic block?
The higher price point reflects the advanced engineering and features, including the unique dual auto/manual ratchet mechanism, higher holding power (up to 21:1), and premium materials, which directly translate to enhanced performance and longevity on the water.
Frequently Asked Questions
What is the holding power of the Ronstan Series 55 Ratchet Orbit Block™?
The Ronstan Series 55 Ratchet Orbit Block™ provides up to 21:1 holding power with its Generation 2 sheave geometry.
What is the difference between auto and manual mode on this ratchet block?
In auto mode, the ratchet engages automatically under load, providing continuous holding power. In manual mode, the ratchet can be disengaged, allowing for free-running of the line for easier adjustment or hoisting.
What is the maximum rope diameter this block can accommodate?
This block is designed to accommodate a maximum rope diameter of 10mm (1/2").
What is the working load limit (WLL) of this block?
The Working Load Limit (M.W.L.) for the Ronstan Series 55 Ratchet Orbit Block™ is 250kg (550lbs).
What types of boats is this block suitable for?
This block is highly suitable for dinghies, sportsboats, and small keel boats up to 8m (26') for applications such as mainsheets, spinnaker sheets, halyards, vangs, and backstays.
