Ronstan Series 55 mm (2 5/32") Ball Bearing Orbit Block - RF55410

The Ronstan Series 55 mm Ball Bearing Quad Orbit Block with a Becket and Swivel Head (RF55410) boasts the highest strength-to-weight ratio available. This is achieved through all-composite reinforced polymer materials. 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
• Easily fitted and securely retained Dyneema Link head

Applications:

• Mainsheet systems on dinghies, sportsboats and small keelboats to 9 m (30')
• Spinnaker sheets on dinghies, sportsboats and small keel boats to 9 m (30')
• Halyard, Vang and Backstay application on boats to 8 m (26')
• Control line applications on larger yachts
• Mainsheet systems and spinnaker sheets on dinghies, catamarans, sportsboats and small keel boats to 9 m (30')
• When paired with a RF56330B and a RF35101 lashed to the becket produces a powerful 8:1 mainsheet system for use on catamarans to 5.5 m (18')

Specifications:

• Safe working load: 1650 lb (748.4 kg)
• Breaking load: 3300 lb (1500 kg)
• Sheave diameter: 2 5/32" (55 mm)
• Maximum line size: 3/8" (10 mm)
• Weight: 11.2 oz (317.5 g)
• 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 impregmented SK75 Dyneema®

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