The Ronstan RF15101 Series 15 Single Block with Loop Head is an ultra-lightweight, high-performance sailing pulley designed for precision control systems where low friction and minimal weight are critical. Featuring a 15mm acetal sheave running on stainless steel ball bearings, it delivers exceptionally smooth operation for high-speed line handling.

Built with UV-stabilised acetal components and stainless steel cheeks, the RF15101 offers excellent durability and corrosion resistance in New Zealand’s demanding marine conditions. Its loop head design with integrated O-ring allows flexible lashing attachment while keeping the running line separated from the fixing point—reducing wear and improving efficiency.

Weighing just around 7g, this is one of the lightest blocks available, making it ideal for dinghy sailing, performance rigs, and fine-tuned control systems such as vang, cunningham, and shock cord setups.

Key Features

• 15mm single sheave for compact, lightweight performance
• Ball bearing system for ultra-low friction operation
• Loop head with O-ring for flexible lashing attachment
• UV-stabilised acetal sheave for durability
• Stainless steel cheeks for corrosion resistance
• Extremely lightweight (approx. 7g) for performance sailing
• Ideal for vang, cunningham, outhaul, and control line systems

Specifications

• Sheave Diameter: 15mm
• Max Rope Diameter: 5mm
• Maximum Working Load: 120kg
• Breaking Load: 550kg
• Weight: Approx. 7g
• Construction: Acetal sheave, stainless steel cheeks
• Head Type: Loop head with O-ring

Why Choose the Ronstan RF15101?  

For New Zealand sailors, reducing friction and weight can significantly improve sailing performance. The RF15101 is designed for high-efficiency control systems, offering smooth line handling and ultra-lightweight construction for racing and precision setups.

Its loop head attachment provides maximum flexibility and minimal line wear, making it ideal for modern rigging systems on dinghies and performance yachts operating in NZ coastal conditions.