Ronstan 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 strength carbon black Aceetal
- Frame/Cheeks: Toughened, glass fiber reinforced Nylon
- Rope Link: UV stabilized, multi-strand impregnated SK75 Dyneema®
- Head fitting: grade 316 stainless steel
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)
- Product Name: Ronstan Series 55 Ratchet Orbit Block - Single - Swivel Head - Auto & Manual
- UPC Number: 9316800440375
- Shop by Brand: Ronstan

Welcome to the Everest Marketplace Seller Storefront, where we're on a mission to equip you with the gear that'll have you thriving in the great outdoors like a legendary Yeti. Whether you're into hunting, fishing, survival, or more, you've stumbled upon the right place!
Got questions about our products? Need to make a return or can't find what you're looking for? Reach out to us at 1-866-806-0934 or drop us a line at info@everest.com.
And hey, if you happen to be a seller with products listed under the Everest storefront, let's chat so we can match those items to your very own kingdom!
Shipping & Returns
All sellers will furnish tracking information for shipped products, whenever relevant. This tracking data enables you to keep tabs on the status of your shipment. If you purchase products from several sellers in one order, you will receive tracking information from each respective seller.
Following the dispatch of your order, Everest.com will send you an email notification containing the tracking details. Kindly ensure that the email address provided during the checkout process is accurate and up to date.
Returns are only accepted for products bought directly from Everest.com. To qualify for a return, the product must be unused, in its original condition, and with the original packaging intact. Some products may be exempt from the return policy. Should you wish to initiate a return, please reach out to the seller directly within 7 days from the date of delivery.
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We prioritize serving those who serve nature. Everest represents the boundless outdoors. Find out how we give back.
Ready to wrestle Yetis over prices? Everest is up for the challenge with our Price Match guarantee.
meet marcus

The Story of Marcus Moose
In the vast wilderness the Everest marketplace, a legendary customer service character emerged—Marcus Moose. With a passion for the outdoors rivaling even the mightiest Yeti, Marcus's mission was clear: guide people to embrace nature's wonders. Marcus, the guardian of adventure, ensured no one was left behind. The wilderness awaits, and with Marcus by your side, your wildest dreams are just a hoofstep away.
Shipping & Returns
All sellers will furnish tracking information for shipped products, whenever relevant. This tracking data enables you to keep tabs on the status of your shipment. If you purchase products from several sellers in one order, you will receive tracking information from each respective seller.
Following the dispatch of your order, Everest.com will send you an email notification containing the tracking details. Kindly ensure that the email address provided during the checkout process is accurate and up to date.
Returns are only accepted for products bought directly from Everest.com. To qualify for a return, the product must be unused, in its original condition, and with the original packaging intact. Some products may be exempt from the return policy. Should you wish to initiate a return, please reach out to the seller directly within 7 days from the date of delivery.
We prioritize serving those who serve nature. Everest represents the boundless outdoors. Find out how we give back.
Ready to wrestle Yetis over prices? Everest is up for the challenge with our Price Match guarantee.
meet marcus

The Story of Marcus Moose
In the vast wilderness the Everest marketplace, a legendary customer service character emerged—Marcus Moose. With a passion for the outdoors rivaling even the mightiest Yeti, Marcus's mission was clear: guide people to embrace nature's wonders. Marcus, the guardian of adventure, ensured no one was left behind. The wilderness awaits, and with Marcus by your side, your wildest dreams are just a hoofstep away.
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 strength carbon black Aceetal
- Frame/Cheeks: Toughened, glass fiber reinforced Nylon
- Rope Link: UV stabilized, multi-strand impregnated SK75 Dyneema®
- Head fitting: grade 316 stainless steel
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)
- Product Name: Ronstan Series 55 Ratchet Orbit Block - Single - Swivel Head - Auto & Manual
- UPC Number: 9316800440375
- Shop by Brand: Ronstan

Welcome to the Everest Marketplace Seller Storefront, where we're on a mission to equip you with the gear that'll have you thriving in the great outdoors like a legendary Yeti. Whether you're into hunting, fishing, survival, or more, you've stumbled upon the right place!
Got questions about our products? Need to make a return or can't find what you're looking for? Reach out to us at 1-866-806-0934 or drop us a line at info@everest.com.
And hey, if you happen to be a seller with products listed under the Everest storefront, let's chat so we can match those items to your very own kingdom!





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