Ronstan RF48500 Series 40 Orbit Ball Bearing Quintuple Block with Swivel Shackle

The Ronstan RF48500 is a Series 40 Orbit ball bearing quintuple (five-sheave) block with an integrated swivel shackle head, engineered for high-performance sailing applications. This advanced block delivers class-leading dynamic and static load ratings in a compact, lightweight package that balances strength, efficiency, and reliability.

Advanced Ball Bearing System:

The RF48500 features Ronstan's innovative 2-stage ball bearing system that minimizes friction across the entire working load range. Primary ball bearings reduce initial friction for effortless trimming, while a secondary full-contact bearing maintains smooth operation under heavy loads. This design ensures consistent performance whether you're making fine adjustments or sheeting under maximum load.

Lightweight High-Strength Construction:

Toughened glass fiber reinforced nylon cheeks replace traditional stainless steel straps, significantly reducing weight without compromising strength. The result is a block that delivers utility-grade performance with race-ready weight savings—ideal for performance-oriented sailors who demand both durability and speed.

Integrated C-Cleat System:

Equipped with Ronstan's carbon-reinforced C-Cleat with stainless steel adjustable arms, this block provides secure rope holding with minimal entry and exit effort. Built-in fairleads enable fast action from any angle, while the adjustable cleat arms let you customize the cleating angle to your preference.

Key Features:

• Five sheaves (quintuple) for high-ratio purchase systems up to 12:1
• Class-leading 1,320 lb maximum working load and 2,650 lb breaking load
• Low-friction 2-stage ball bearing system for smooth, efficient operation
• Swivel shackle head for flexible attachment and load alignment
• Compact, low-profile design at just 8.5 oz
• Accommodates rope up to 3/8 inch diameter
• 1-9/16 inch sheave diameter optimized for performance
• Toughened glass fiber reinforced nylon construction

Applications:

• Mainsheet and spinnaker sheet systems on dinghies, beach catamarans, and sportsboats to 26 feet
• Halyard, vang, and backstay systems on boats to 30 feet
• Control line applications on larger yachts requiring high-ratio purchase
• Any sailing application requiring efficient multi-part purchase systems

Technical Specifications:

• Sheave Diameter: 1-9/16 inches (40mm)
• Maximum Rope Diameter: 3/8 inch
• Pin Diameter: 5/32 inch
• Maximum Working Load: 1,320 lbs (600 kg)
• Breaking Load: 2,650 lbs (1,200 kg)
• Weight: 8.5 oz (241 g)
• Number of Sheaves: 5 (Quintuple)
• Bearing Type: 2-stage ball bearing

The Ronstan Series 40 Orbit Blocks represent the perfect convergence of racing technology and cruising reliability, providing sailors with professional-grade performance in a versatile, accessible package.