Click to enlargeRonstan Series 55 Ratchet Orbit Block™ - Single - Swivel Head - Auto & Manual
Manufacturer: RonstanPart #: RF56100SKU: 55257
- Stainless Steel
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Item #: 55257
Category: Blocks
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Description
Series 55 Ratchet Orbit Block™ - Single - Swivel Head - Auto & Manual Automatic Ratchet Block Now you can enjoy the flexibility of setting up your ratchet blocks to suit yourself. Ronstan is the only company that offers a ratchet block with both auto and manual engagement modes.
In the auto mode of the ratchet mechanism engages when load is applied, but switches off when it's released. This lets the sheet run out smoothly and freely-great for rapid easing of the sheet and for gybing asymmetric spinnakers.
In manual mode, the ratchet mechanism can be switched on or off as required. This is the preferred mainsheet set-up for may top sailors.
Try the block in both modes and see which you prefer - you really can't go wrong. Awesome Ratchet Block Holding Power Quite simply, Ronstan Ratchet Orbit Blocks™ have the highest holding power available.
The sophisticated NC-machined sheave features Generation 2 of our sheave cross-hole geometry. Its holding power is up to 21:1, almost double that of our nearest competitior.
The unique sheave design has 12 gripping faces which directly resist loaded line movement. Traditional designes have only 8 faces with an angled resistance to line movement.
Our Generation 2 design has straight resistance faces which both distribute the load and minimise rope wear. These faces are offset from the radial line, to draw the rope down into the gripping area when under load.
Features: Up to 20:1 holding power Smooth easing of sheets High performance cleating Swivel shackle head for unlimited block rotation. Stainless steel shackle head for ultimate durability and compatibility with harsh fixing points.
Automatic & manual ratchet block Applications: Mainsheet systems and spinnaker sheets on dinghies, sportsboats and small keel boats to 8M(26') Halyard, vang and backstay applications on boats to 8M(26') Spinnaker sheets on sportsboats and small keel boats (lateral lead blocks) Materials: Sheave: Hard anodised Aluminium Ball Bearings: High compression
Specifications
| Brand | Ronstan |
|---|---|
| Part Number | RF56100 |
| EverTide SKU | 55257 |
| UPC | 9316800440375 |
| Material | Stainless Steel |
Specifications are provided by the manufacturer. Confirm fitment for your application before ordering, or contact us and we'll help.
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Returns & warranty
Returns are accepted within 30 dayson items that are unused and in their original packaging. Some items may be subject to a manufacturer restocking fee. Special-order items may not be eligible — if you're unsure, ask us before ordering.
Ronstan productscarry the manufacturer's standard warranty. For a warranty claim or a return authorization, see our full returns policy or contact us.
Sailing — frequently asked
- How do I size a block for my sailboat?
- Match the block to the line diameter it will carry and to the working and breaking loads of the system (sheet, halyard, control line). Makers publish load ratings and line-size ranges — choose a block whose working load comfortably exceeds the real-world load, without going so large it adds needless weight.
- What is running rigging?
- Running rigging is the moving lines that control the sails — sheets, halyards, and control lines — as opposed to standing rigging (the fixed wire that holds up the mast). Running rigging should be matched to the boat’s blocks, clutches, and winches for smooth, reliable sail handling.
- How do I maintain sailboat winches and hardware?
- Rinse with fresh water after sailing, keep sheaves and bearings clean, and periodically service winches (disassemble, clean, and re-grease per the maker’s instructions). Marine-grade stainless and good maintenance keep hardware working smoothly when loads are high and timing matters.
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