Ronstan Series 55 Ratchet Orbit Block - RF56120

The Ronstan Series 55 Ratchet Orbit Block™ with Becket, Cam Cleat and Swivel Head (RF56120) has 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 20:1, 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. The Generation 2 design has straight resistance faces which both distribute the load and minimize rope wear. These faces are offset from the radial line, to draw the rope down into the gripping area when under load.

Features:

• Ultra lightweight
• Low friction 2-stage Orbital ball bearing system
• Highest working load in its class
• Easily fitted and securely retained Dyneema Link head
• Low profile and compact
• High performance cleating

Applications:

• Mainsheet systems on dinghies, sports boats and small keel boats to 9m (30 ft.)
• Spinnaker sheets on dinghies, sports boats and small keel boats to 9m (30 ft.)
• Halyard, vang and backstay application on boast to 8m (26 ft.)
• Control line applications on larger yachts

Specifications:

• Safe working load: 550 lbs (250 kg)
• Breaking load: 1650 lbs (748 kg)
• Weight: 3.0 oz. (85.1 g)
• Sheave diameter: 2-5/32" (55 mm)
• Maximum line size: 3/8" (10 mm)
• Materials:
  • Ball bearings - High compression strength carbon black Acetal
  • Stage 2 bearing - Carbon fiber reinforced, PTFE impregnated Nylon
  • Frame/cheeks - Toughened, glass fiber reinforced Nylon
  • Rope link: UV stabilized, multi-strand impregnated SK75 Dyneema®