Ronstan Series 55 Orbit Block With Becket And Swivel Shackle Head

Ronstan 55mm ball bearing Orbit block with becket option and swivel shackle head

Ball bearing Orbit blocks™ boast the highest strength-to-weight ratio available. This is achieved through all-composite reinforced polymer materials and multiple attachment options. 
Their precision design provides the optimum number of ball bearings for minimum friction while weight reduction is achieved through the use of fibre-reinforced composites in the block head, cleat arms and beckets.

Features

• Ultra Lightweight
• Low friction 2-stage Orbital ball bearing system
• Highest working load in its class
• Low profile and compact
• High performance cleating
• Swivel shackle head for unlimited block rotation.
• Stainless steel shackle head for ultimate durability and compatibility with harsh
• fixing points.
• Ultra low profile integrated becket.

Materials

• Frame/Cheeks - Toughened, glass fibre reinforced Nylon
• Sheave: Carbon fibre reinforced, PTFE impregnated Nylon.
• Head fitting: Grade 316 stainless steel.
• Ball Bearings: High compression strength carbon black Acetal.
• Stage 2 Bearing: Glass fibre reinforced, MoS2 impregnated Nylon.

Applications

• Mainsheet systems on dinghies, sportsboats and small keelboats to 9m (30ft)
• Spinnaker sheets on dinghies, sportsboats and small keel boats to 9m (30ft)
• Halyard, Vang and Backstay application on boats to 8m (26ft)
• Control line applications on larger yachts

Lightweight
Kilogram for kilogram of working load BB Orbit Blocks™ are the world’s lightest. To gain peak performance, we engineered out the heavy steel load straps, head post, shackle and cleating accessories. Through extensive research and development, we replaced virtually all metal components with high-tech polymers and fibre equivalents.
Weight and bulk are further reduced in the different block configurations. The ball bearing single and becket block has a through-sheave becket arrangement. The result? The lowest weight possible. 

Highest working load in its class
The proven Ronstan 2-stage bearing system (Series 30 and larger) features high compression grade Acetal ball bearings and a secondary toughened, glass fibre reinforced Nylon full-contact bearing. This gives minimum friction across the full working load range. 
The sheave and bearing system is supported by a fibre-reinforced load frame, computer modelled and optimised using advanced stress analysis methods. The Dyneema® Link is produced from high spec SK75 fibre, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point.

Low profile and compact
The flexible Dyneema® Link used in provides 0° or 90° orientation. It connects directly to the head of the block rather than to an intermediate head post. This reduces weight and gives the lowest possible profile while allowing full articulation. 
These blocks are far more compatible with Dyneema®/Spectra® lines, carbon laminate connection points and webbing than traditional blocks with steel loop tops or shackles.