Ronstan RF35109HL Series 30 Ball Bearing Block, Single Becket Lashing

Series 30 Ball Bearing Block Single Becket Option Lashing

Ball Bearing 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.

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 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, used in multi-sheave blocks, 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.

Simple, Versatile Secure Attachment

The single block is easily lashed to an attachment point, and can also accept Dyneema Links and shackles for a variety of efficient attachment alternatives. The Dyneema Link used in multi-sheave blocks is easily fitted and secured by a removable pin. The Dyneema Link can also be removed and replaced by a shackle, custom lashing or strop.

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.

Low Profile Compact

The two way head in the single lashing block allows for alignment at 0 or 90 orientation, while the single swivel block allows for full articulation.

The flexible Dyneema Link used in multi-sheave blocks 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. Beckets have been carefully designed to minimise height.

Features:

• Lightweight
• Highest working load in its class
• Secure, versatile and secure attachement
• Low profile and compact
• Ultra low profile thru-sheave becket
• Self-lubricating Nylatron sheave and full contact bearing for high dynamic loads

Applications:

• Mainsheet systems and spinnaker sheets on dinghies to 5M(16')
• Halyard, vang and backstay applications on boats to 5M(16')
• Control line applications on larger yachts

The Ronstan RF35109HL Series 30 Ball Bearing Block is a lightweight, low-profile single becket block designed for efficient line handling on dinghies, small boats, and larger yacht control-line systems. Its all-composite reinforced polymer construction and precision ball-bearing system help reduce friction while delivering a strong, compact solution for mainsheet, spinnaker sheet, halyard, vang, and backstay applications.

Designed for versatile attachment, this single lashing block can be secured directly to an attachment point and can also accommodate alternative connections such as Dyneema Links, shackles, custom lashings, or strops. Its two-way head supports alignment at 0- or 90-degree orientations, while the compact design helps maintain a low-profile installation. The block is also compatible with Dyneema or Spectra line systems, carbon laminate connection points, and webbing.

Ronstan’s proven two-stage bearing system uses high-compression-grade Acetal ball bearings and a secondary full-contact bearing to provide low friction across the working load range. A fibre-reinforced load frame supports the sheave and bearing system, while the self-lubricating Nylatron sheave is designed for high dynamic loads. The single becket configuration provides a practical option for compact sailboat rigging and control-line applications where dependable, space-conscious hardware is needed.

Choose the Ronstan RF35109HL Series 30 Ball Bearing Block for a secure, adaptable, and lightweight solution for modern sailing hardware systems.

Key Features:

• Lightweight construction: All-composite reinforced polymer materials help reduce hardware weight.
• Efficient bearing system: Two-stage bearing design with Acetal ball bearings and a secondary full-contact bearing supports low-friction operation.
• Versatile attachment: Single lashing design accepts direct lashing and can accommodate Dyneema Links, shackles, custom lashings, or strops.
• Low-profile design: Compact block geometry and carefully designed becket help minimize installation height.
• Flexible alignment: Two-way head allows 0- or 90-degree orientation.
• High-load capability: Fibre-reinforced load frame and self-lubricating Nylatron sheave support high dynamic loads.

Product Details:

• Brand: Ronstan
• Model: Series 30
• Part number: RF35109HL
• Block type: Ball bearing block with single becket and lashing attachment
• Overall size: Approximately 2 inches long by 2 inches wide by 1 inch high
• Weight: Approximately 1.6 ounces
• Recommended applications: Mainsheet and spinnaker sheet systems on dinghies up to 16 feet; halyard, vang, and backstay applications on boats up to 16 feet; control-line applications on larger yachts