Ronstan Series 40 Ball-Bearing Cheek Block

The Ronstan Series 40 ball-bearing cheek blocks are engineered for optimal strength, performance, and reliability. They boast class-leading dynamic and static load ratings, making them the top choice in their category. Constructed with lightweight, toughened glass fiber reinforced nylon for cheeks, these blocks replace traditional stainless steel straps, enhancing both performance and durability.

This versatile range includes single swivel blocks and options for single and double sheave configurations, suitable for lashing or soft attachments. Users can build advanced systems, including a 12:1 purchase mainsheet system ideal for performance catamarans.

The blocks feature a carbon-reinforced C-Cleat™ for secure rope retention, with low entry and exit efforts, complemented by fairleads for quick action from any angle. Stainless steel cleat arms are adjustable for personalized cleating angles.

Ball-bearing configurations utilize a unique 2-stage bearing system, significantly reducing friction, along with a full-contact bearing to ensure low friction throughout the complete working load range.

High Load versions are tailored for applications facing significant dynamic or static loads, equipped with a high-strength 2205 stainless steel sheave and hub, alongside a triple bearing race to minimize friction under high loads.

Applications:

• Mainsheet systems and spinnaker sheets on dinghies and off-the-beach catamarans (up to 8m or 26ft).
• Halyard, vang, and backstay systems on boats up to 9m (30ft).
• Control line applications on larger yachts.

Specifications:

• Sheave Ø: 1-9/16 in.
• Max. Rope Ø: 3/8 in.
• M.W.L.: 880 lb.
• B. L.: 1760 lb.
• Weight: 1.2 oz.

• Outstanding dynamic and static load ratings.
• Lightweight and durable construction using glass fiber reinforced nylon.
• Efficient low friction 2-stage ball-bearing system.
• Flexible attachment options including soft, lashing, and traditional swivel shackle heads.
• Compact low-profile design.
• High-performance cleating capabilities.