Ronstan Orbit Series 55 Single Fiddle Block w/ Becket, Swivel Head & Cam Cleat

Item #


Usually ships within 1-3 days

Product Description

Ronstan Orbit Series 55 Single Fiddle Block w/ Becket, Swivel Head & Cam Cleat


  • Automatic and Manual ratchet in one block

  • Up to 20:1 holding power

  • Smooth easing of sheets

  • High performance cleating

    Sheave Ø - 2 5/32 + 1 3/8 in. ((55 + 35mm)

    Max. Rope Ø - 3/8 in. (10mm)

    Max. Cable Ø - in. (mm)

    Pin Ø - in. (mm)

    M.W.L. - 550 lb. (250 kg)

    B. L. - 1650 lb. (750 kg)

    Weight - 8.3 oz. (235 g)

  • Fiddle sheave has a high load full contact bearing (ie. not ball bearing). Main sheave has two-stage, ball bearing.

    Product 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.


  • Sheave: Hard anodized Aluminum

  • Ball Bearings: High compression strength carbon black Acetal

  • Frame/Cheeks: Toughened, glass fiber reinforced Nylon

  • Rope Link: UV stabilized, multi-strand impregnated SK75 Dyneema®