Ronstan Core Blocks

Core Blocks™ are a true all round solution. A tuned 2-stage bearing system provides excellent performance across the full working load range with an integrated thrust bearing feature and the resilience to handle high dynamic or static loads. Acetal & aluminum sheave options, alloy cheeks and stainless fixings complete the durable package. For reliability and a long service life, these blocks are the right choice for sheets, halyards and control line applications for cruising and racing.


  •  Class leading performance and sleek, contemporary styling
  •  Excellent dynamic and high static load performance
  •  Less than half the friction of the nearest competitor
  •  Durable aluminum alloy cheek plates
  •  Central hub hole can be used as a becket take-off or tie-up point