Antal Mainsheet System F4 – 4:1 / 8:1, Double-Ended, SWL 800kg

The Antal F4 Mainsheet System is a compact, dual-speed mainsail control solution designed for yachts up to approximately 36 feet. Offering both 4:1 and 8:1 mechanical advantages in a single, integrated system, it is ideal for sailors who want fast sheet recovery with the option for fine-tuned adjustment under higher loads.

This double-ended system allows one tail to function as a quick 4:1 sheet, while the other activates the high-load 8:1 purchase for precise trimming. Built for efficiency and ease of use, the F4 uses a three-block configuration with a clearly defined reeving path and dual cam cleats for complete control from both ends.

System Configuration

• Lower Block:
  Features two inline sheaves and twin cam cleats, allowing simultaneous access to both 4:1 and 8:1 sheet tails. This innovative design is at the core of the F4’s dual-speed function.
• Upper Block:
  A double block mounted to the boom handles the upper reeving in both modes.
• Intermediate Block:
  A single floating block redirects the sheet path and enables the 8:1 mechanical advantage when needed.

Key Features

• Dual-Speed Functionality
  • 4:1 mode for rapid sail trimming or easing in light-to-moderate conditions
  • 8:1 mode for high-load adjustments and precise tuning under pressure
• Double-Ended Operation
  Separate tails for each mode, both led to the lower block and managed via independent cam cleats—giving the trimmer intuitive and immediate control over both sheet speeds.
• Low-Friction Operation
  Sheaves are equipped with dual ball bearings for smooth, efficient line movement, even under high load.
• Compact & Lightweight
  Optimised for minimal bulk in the cockpit or traveller area, ideal for performance cruisers and racing yachts.
• Marine-Grade Construction
  Built from anodised aluminium and stainless steel for high strength and durability in harsh saltwater environments.

Specifications

• Mechanical Advantage: 4:1 and 8:1
• Sheave Sizes: 60 mm (main lower sheaves), 50 mm (intermediate and upper)
• Cam Cleats: Twin integrated on lower block
• Rope Compatibility: Up to Ø10 mm
• Safe Working Load (SWL): 800 kg
• Recommended Boat Size: Up to 36 ft (11 m)

The Antal F4 is a highly versatile and compact mainsheet system designed for sailors who demand both speed and control. Whether racing or cruising, it offers efficient line handling, durable performance, and the adaptability to suit changing conditions—all in one tidy package.