Ronstan RF20141 Stand-Up Ball Bearing Pulley 20mm – Series 20 Block

The Ronstan RF20141 Stand-Up Ball Bearing Pulley (20mm) is a compact, high-performance Series 20 block designed for deck-mounted control systems where alignment and efficiency are critical.

Featuring a 20mm acetal sheave running on precision stainless steel ball bearings, this block delivers exceptionally low friction and smooth operation, making it ideal for frequently adjusted control lines such as vangs, travellers, and cunningham systems.

The stand-up design keeps the block upright under load, ensuring consistent line alignment and preventing twisting or misfeeding—particularly useful in dynamic sailing conditions.

Constructed from UV-stabilised acetal, fibre-reinforced nylon, and 316 stainless steel load components, the RF20141 offers excellent strength, corrosion resistance, and long-term durability in harsh marine environments.

Despite its lightweight design (~20g), this block provides a maximum working load of 250kg and breaking load of 550kg, making it suitable for a wide range of applications on dinghies, skiffs, and small keelboats.

Key Features

• 20mm ball bearing sheave – smooth, low-friction performance
• Stand-up base design – maintains upright position under load
• High load capacity (250kg MWL / 550kg BL)
• Compact and lightweight (~20g)
• 316 stainless steel load strap – corrosion-resistant
• UV-stabilised acetal sheave – durable and low maintenance
• Ideal for deck or spar mounting

Specifications

• Brand: Ronstan
• Model: RF20141
• Series: 20 Ball Bearing
• Product Type: Stand-up pulley block
• Sheave Diameter: 20mm
• Max Rope Diameter: 6mm
• Maximum Working Load: 250kg
• Breaking Load: 550kg
• Weight: ~20g
• Materials:
  • UV-stabilised acetal sheave
  • Stainless steel ball bearings
  • 316 stainless steel load strap
  • Fibre-reinforced nylon cheeks

Ideal Applications

• Vang systems
• Cunningham and outhaul controls
• Traveller systems
• Dinghy and skiff rigging
• Deck-mounted control line leads

This block is ideal where you need consistent line alignment and smooth performance in a fixed deck-mounted setup.

Why Buy from Barton Marine NZ?

• Trusted NZ Ronstan supplier
• Fast nationwide delivery
• Genuine high-performance sailing hardware
• Ideal for NZ racing and cruising conditions

Pro Tip 

• Position carefully to maintain clean lead angles and minimise friction
• Ideal for frequently adjusted control lines where alignment matters most