Ronstan Series 55 Ball Bearing Orbit Double Block - 55 mm (2 5/32") - RF55210

Ronstan Ball Bearing Orbit Blocks™ boast the highest strength-to-weight ratio available. This is achieved through all-composite reinforced polymer materials and a Dyneema® rope link head. Their precision design allows the optimum number of ball bearings in loaded areas and eliminates them in inactive areas. Ineffective mass is reduced even further through fiber-reinforced composites in the block head, cleat arms and beckets.

Features:

• Ultra Lightweight
• Low friction 2-stage Orbital ball bearing system
• Highest working load in its class
• Low profile and compact
• High performance cleating
• Swivel shackle head for unlimited block rotation
• Stainless steel shackle head for ultimate durability and compatibility with harsh fixing points
• Ultra low profile integrated beckets
• Applications:
  • Mainsheet systems on dinghies, sportsboats and small keelboats to 9m (30ft)
  • Spinnaker sheets on dinghies, sportsboats and small keel boats to 9m (30ft)
  • Halyard, Vang and Backstay application on boats to 8m (26ft)
  • Control line applications on larger yachts
  • Mainsheet systems and spinnaker sheets on dinghies, catamarans, sportsboats and small keel boats to 9m (30ft)
  • Halyard, vang and backstay applications on boats to 8m (26ft)
  • Control line applications on larger yachts

Specifications:

• Sheave: 2 5/32"
• Max. Line Size: 3/8"
• Max. Working Load: 1650 lbs
• Breaking Load: 3300 lbs
• Weight: 6.1 oz

Total block load. Load on becket not to exceed 33% of block load. ie. MWL 250 kg (550 lb), BL 500kg (1100 lb)

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 SK75 Dyneema®
• Head fitting: grade 316 stainless steel
• Ball Bearings: high compression strength carbon black Acetal