Ronstan 55mm Orbit Blocks

The orbital ball-bearing arrangement gives the largest possible bearing race diameter. This maximizes 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 fiber-reinforced load frame. The design was computer modeled to be stress optimized. The Dyneema^® Link is produced from FSE Robline SK75 fiber, which is 10 times stronger and lighter than steel, and provides the final connection from the block to the load point.

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