Ronstan Marine Systems DivisionRonstan Marine Systems Division
 
 

Series 55 Ratchet Orbit Block™

 

Range Information | Applications | Materials | Related Items

Smart Features
  •  Automatic and Manual ratchet in one block
  •  Up to 20:1 holding power
  •  Smooth easing of sheets
  •  High performance cleating

 

   
Product No.
Desc.
Sheave ØMax. Rope ØMax. Cable ØPin ØM.W.L.B. L.Weight

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Stock

Price

  in.in.inin. lb.lb.oz.        
 RF56100 RF56100 > Single, swivel head, auto & manual

2 5/32

3/8

550

1430

2.9


 
 

  QTY
 

IN
STOCK

Price

$ 73.95

 RF56101 RF56101 > Single, auto & manual

2 5/32

3/8

-

-

550

1650

2.8


 
 

  QTY
 

IN
STOCK

Price

$ 70.95

 RF56111 RF56111 > Single, becket, auto & manual

2 5/32

3/8

-

-

550

1650

2.9


 
 

  QTY
 

IN
STOCK

Price

$ 74.95

 RF56121 RF56121 > Single, adjustable cleat, auto**

2 5/32

3/8

-

-

550

1650

7.1


 
 

  QTY
 

IN
STOCK

Price

$ 141.95

 RF56131 RF56131 > Single, becket, adjustable cleat, auto**

2 5/32

3/8

-

-

550

1650

7.2


 
 

  QTY
 

IN
STOCK

Price

$ 145.95

 RF56151 RF56151 > Cheek, clockwise, auto & manual

2 5/32

3/8

-

-

550

1540

2.7


 
 

  QTY
 

IN
STOCK

Price

$ 68.95

 RF56151A RF56151A > Cheek, anti-clockwise, auto & manual

2 5/32

3/8

-

-

550

1540

2.7


 
 

  QTY
 

IN
STOCK

Price

$ 68.95

 RF56331 RF56331 > Triple, becket, adjustable cleat, auto**

2 5/32

3/8

-

-

1650

3300

12.2


 
 

  QTY
 

IN
STOCK

Price

$ 202.95

 RF56331B RF56331B > Triple, underhung becket, adjustable cleat, auto**

2 5/32

3/8

1650

3300

349


 
 

NOT
AVAILABLE
ONLINE

---

Price

$ 206.95

 RF56511 RF56511 > Fiddle*, becket, auto

2 5/32 + 1 3/8

3/8

550

1650

3.8


 
 

  QTY
 

IN
STOCK

Price

$ 76.95

 RF56531 RF56531 > Fiddle*, becket, adjustable cleat, auto**

2 5/32 + 1 3/8

1650

550

8.6


 
 

NOT
AVAILABLE
ONLINE

---

Price

$ 117.95

These blocks have been specifically designed and optimised for use on racing sailboats and the conditions encountered in this unique application. They should not be assumed suitable for other non-marine or industrial applications. For further details on associated risks see Orbit Block Usage and Considerations
**  This block has full Automatic ratchet engagement only.  ie. No On/Off manual mode operation
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Range Information

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.

* Selected Series 55 models.
 

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 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. 

 

      
  
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Materials
  • 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®
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Related Items
  Product No. Description
199A

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