Ronstan Series 55 Orbit Ratchet Single Block
- Automatic and Manual ratchet in one block.
- 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.
- Sheave Diam: 55 mm
- Max. Rope Diam: 10mm
- Max. Working Load: 250 kg
- Breaking Load: 650 kg
- Weight: 82 g
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
* Selected Series 55 models.
Simple and secure attachment
The Dyneema® Link is easily fitted and is retained securely by a moulded retainer clip. The flexible link can be left with one end attached to the block when fitting - no more lost shackle pins.
The system is compatible with Dyneema®/Spectra® strops, webbing and carbon connection points - much more so than steel loop tops or shackles.
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 patented sheave cross-hole geometry. Its holding power is up to 21:1, almost double that of our nearest competitor.
The unique sheave design has 12 gripping faces which directly resist loaded line movement. Traditional designs 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.
- Dinghy mainsheet systems
- Spinnaker sheets on dinghies
- Control line applications on larger yachts
- Mainsheet systems and spinnaker sheets on dinghies, sportsboats and small keel boats to 8m(26ft).
- Halyard, vang and backstay applications on boats to 8m (26ft).
- Spinnaker sheets on sportsboats and small keel boats (lateral lead blocks)
- Sheave: Hard anodised Aluminium
- Ball Bearings: High compression strength carbon black Aceetal
- Frame/Cheeks: Toughened, glass fibre reinforced Nylon
- Rope Link: UV stabilised, multi-strand impregnated SK75 Dyneema®
- Head fitting: grade 316 stainless steel.
- Ball Bearings: High compression strength carbon black Acetal.
- Sheave : Hard anodised aluminium.
Australia Post and our Commercial Couriers are expecting the festive season to be extra busy this year. Based on their advice, we cannot guarantee orders placed after the cut-off dates listed below will be delivered by Christmas.
To avoid disappointment place your Christmas orders as early as possible.
Overseas, offshore islands and distant mainland locations may take up to 3 or 4 weeks to deliver. Please contact your local Mail Order Department to discuss specific details relating to your situation.
All orders are shipped from our Brookvale, Sydney order fulfilment centre. Orders are normally shipped within 5 business days - most quicker!
Shipping day estimates after your order leaves our fulfilment centre in Sydney are based on Australia Post domestic delivery times:
|ACT||2 - 3 business days||1 - 2 business days|
|NSW||2 - 4 business days||1 - 3 business days|
|NT||4 - 13 business days||3 - 5 business days|
|QLD||3 -12 business days||2 - 4 business days|
|SA||3 - 5 business days||2 - 4 business days|
|TAS||4 - 8 business days||2 - 4 business days|
|VIC||3 - 5 business days||2 - 3 business days|
|WA||5 - 10 business days||2 - 6 business days|
Last updated 12/09/2023
* These delivery times are an estimate and actual delivery times may vary based on peak periods and other external factors. Bulky orders may take longer.
Shipping rates are automatically calculated based on live quotes supplied by our shipping partners. The quote takes into consideration, the bulk of your cart, where you want it delivered and if you want express or standard shipping.
Get a shipping rate estimate by adding items to your online cart. Go to the cart by clicking on the shopping cart icon located at the top right of the page. Then enter your shipping destination information into the "Estimate Shipping and Tax" section of the shopping cart summary.
We are currently unable to deliver online orders outside of Australia.
If you are located outside of Australia and wish to place an order offline. Please contact our Mail Order department or send us an enquiry via the orange help bubble located at the bottom right of this page.
Online purchases can be returned/exchanged within 30 days. Some exclusions do apply.
Visit our Returns Policy page for details on how you can return an item.