Ronstan Core Blocks™ is 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 sheave, alloy cheeks, and stainless fixings complete the durable package. For reliability and long service life, these blocks are the right choice for sheets, halyards, and control line applications for cruising and racing.
Universal Bearing - Dynamic and high static load performance.
The Ronstan Universal Bearing incorporates our proven 2-stage bearing system.
Stage 1 - Under moderate loads, Acetal ball bearings ensure minimum friction.
Stage 2 - Under heavy loads, where deformation of ball bearings alone would result in increased friction, a sliding Acetal bearing on a polished stainless steel race takes over, maintaining low friction performance.
Additionally, the ball bearings are configured to act as a thrust bearing between the sheave and cheeks, preventing the sheave from rubbing on the cheeks and causing friction when the line lead in and out of the block isn’t perfect. Particularly important for cheek blocks. Alloy cheek plates Block cheeks are manufactured from the highest quality alloy for maximum strength. Material optimization and the cut-away design minimize weight and allow easy fresh water rinsing of salt and debris from the bearings. The cheek design has been further styled with flaring at the block throat and reduced the gap between the cheek and sheave, minimizing rope wear.
Universal head The head assembly incorporates a brass bearing washer to provide smooth 360° rotation of the post and shackle. A set screw arrangement allows the head to be locked at 0° or 90°. Shackles are high-quality forged grade 316 stainless steel. Suits pre-spliced lines. Removable becket pins allow the fitting of pre-spliced lines. The flush fit becket pin head is kind on deck surfaces and won’t snag lines.
Note: Special Order Only