Ronstan RF28109HL Series 25 High Load Orbit Pulley 25mm

The Ronstan RF28109HL Series 25 High Load Orbit Pulley is a premium low-friction sailing block engineered for extreme high-load dinghy, foiling, skiff, and sports boat applications in demanding New Zealand sailing conditions. As part of Ronstan’s advanced Orbit Block™ HHL range, the RF28109HL combines ultra-lightweight construction with exceptional strength and smooth load handling for modern performance sailing systems.

Designed specifically for high dynamic load applications using small-diameter control lines, the RF28109HL features a Grade 2205 stainless steel sheave and bearing race paired with Grade 304 stainless steel ball bearings for outstanding load capacity and durability. Ronstan developed the High Load (HHL) Orbit Blocks™ to meet the demands of modern foiling boats and high-performance sailing systems where compact blocks must safely handle significant loads.

The advanced 2-stage ball bearing system delivers exceptionally low-friction operation under both static and dynamic loading, improving trimming precision and sail handling efficiency. Its lashing head attachment system allows lightweight soft rigging installation while reducing metal hardware weight and increasing rigging flexibility.

The compact 25mm design is ideal for mainsheet systems, cascading vang systems, cunninghams, spinnaker turning blocks, barber haulers, and high-load control lines on dinghies and sports boats up to approximately 4 metres (13ft). Ronstan specifically states the Series 25 Orbit Blocks™ deliver “superior strength, reduced weight, and exceptional performance.”

Key Features

• Genuine Ronstan RF28109HL Orbit Block
• 25mm high-load single pulley block
• High Load (HHL) Orbit Block™ design
• Grade 2205 stainless steel sheave and bearing race
• Grade 304 stainless steel ball bearings
• Advanced 2-stage ball bearing system
• Lightweight lashing head attachment
• Extremely low-friction operation
• Compact high-strength construction
• Hollow hub for becket take-off
• Suitable for up to 8mm rope
• Ideal for foiling and high-performance sailing

Ronstan states the RF28109HL is “purpose-built for high-load applications” and increasingly used on “modern performance and foiling boats.”

Why Buy the Ronstan RF28109HL from Barton Marine NZ?

At Barton Marine NZ we supply genuine Ronstan sailing hardware trusted by competitive New Zealand sailors and marine professionals. The RF28109HL is an ideal solution for lightweight high-load sail control systems where low friction, durability, and strength are critical.

Perfect for:

• Foiling dinghies
• High-performance skiffs
• Sports boats
• Mainsheet systems
• Cascading vang systems
• Cunningham controls
• Barber haulers
• Spinnaker sheet turning systems
• Lightweight racing rigging
• High-load sail controls

Technical Specifications

Ronstan specifications list:

• Sheave diameter: 25mm
• Maximum rope diameter: 8mm
• M.W.L: 250kg
• Breaking Load: 550kg
• Weight: 14g

Common Applications

The Ronstan RF28109HL is commonly used for:

• Foiling dinghy control systems
• High-load control lines
• Mainsheet turning blocks
• Cascading vang systems
• Cunningham systems
• Barber haulers
• Sports boat rigging
• Spinnaker sheet systems
• Lightweight racing applications
• High-performance trimming systems

Ronstan recommends the Series 25 Orbit Blocks™ for:

• “Control lines”
• “Mainsheet and spinnaker sheet turning blocks”
• “Cascading vangs”
• “Leech lines & cunninghams”

Performance Benefits

The Ronstan RF28109HL provides:

• Extremely low-friction operation
• Exceptional strength-to-weight ratio
• Reliable high-load performance
• Smooth trimming under load
• Lightweight racing efficiency
• Excellent corrosion resistance
• Long-lasting marine durability

The Grade 2205 stainless steel sheave and bearing race help improve load handling and durability in demanding racing applications.