Ronstan Series 55 BB Orbit Block, Fiddle Becket Cleat Swivel

Manufacturer part #: RF55530

Ultra Lightweight

Low friction 2-stage Orbital ball bearing system

Highest working load in its class

Low profile and compact

High performance cleating

Lightweight
Kilogram for kilogram of working load, BB and RT Orbit Blocks„¢ are the world's lightest. The unique orbital design allows the bearing to only be in the active areas of the floating sheave. This minimises the mass of the inactive return race and hub.

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.

Multi-sheave blocks have only single intermediate cheeks and an ultra-light and efficient head arrangement. This gives a 30% weight saving advantage over the nearest competitor. Other brands just link together their single blocks. This results in unnecessary double cheeks between each sheave, held together by a heavy steel channel across the top of the block.

Highest working load in its class
The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximises load performance. The proven Ronstan 2-stage bearing system features high compression grade acetal ball bearings and a secondary full-contact bearing. This gives minimum friction across the full working load range.

The floating sheave and bearing system is supported by a fibre-reinforced load frame. The design was computer modelled to be stress optimised. The Dyneema° Link is produced from FSE Robline SK75 fibre, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point.

Applications

Mainsheet systems on dinghies, sportsboats and small keelboats to 9 m (30 ft)

Spinnaker sheets on dinghies, sportsboats and small keel boats to 9 m (30 ft)

Halyard, Vang and Backstay application on boats to 8 m (26 ft)

Control line applications on larger yachts

Materials

Ball bearings - High compression strength carbon black Acetal

Stage 2 bearing - Carbon fibre reinforced, PTFE impregnated Nylon

Frame/Cheeks - Toughened, glass fibre reinforced Nylon

Rope Link: UV stabilised, multi-strand impregmented SK75 Dyneema°