Ronstan, Series 55 Orbit Block™, Single Link Head, RF55101

Description

The Series 55 Orbit Block™ is designed to be lightweight and efficient. Utilizing a unique orbital design, the bearing is positioned only in the active areas of the floating sheave, minimizing the mass of the inactive return race and hub. This design reduces weight and bulk across different block configurations. The ball bearing single and becket block features a through-sheave becket arrangement, resulting in the lowest weight possible. Multi-sheave blocks have single intermediate cheeks and an ultra-light head arrangement, providing a 30% weight saving over competitors.

The block offers the highest working load in its class due to the orbital ball-bearing arrangement, which maximizes the bearing race diameter and load performance. The Ronstan 2-stage bearing system, with high compression grade acetal ball bearings and a secondary full-contact bearing, ensures minimal friction across the working load range. The floating sheave and bearing system are supported by a fiber-reinforced load frame, stress-optimized through computer modeling. The Dyneema® Link, made from FSE Robline SK75 fiber, is 10 times stronger and lighter than steel, providing a secure connection from the block.

Features include ultra-lightweight construction, a low friction 2-stage orbital ball bearing system, and the highest working load in its class. The block is low profile, compact, and features high-performance cleating with an easily fitted and securely retained Dyneema® Link head.

Specifications

• B.L. (kg): 1000
• M.W.L. (kg): 500
• Max. Rope diameter (mm): 10
• Notes: Replacement Link: RF9004-08. Replacement Retainer Clip: RF5001
• Sheave diameter (mm): 55
• Type of Block: Single
• Weight (g): 68