Series 20 Single Cheek Block

Series 20 Single Cheek Block

5 out of 5 Customer Rating
  • In Stock
Ships from supplier, typically 2-3 weeks.

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Model # 1787225 Mfg # RF20151
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Ball bearing blocks deliver high performance and sensitivity for static and dynamic loads.

A smooth and efficient block is critical to the conversation between sailor and boat—especially for hand-held control lines. Ronstan designed the Series 20 to give dinghy and small keelboat sailors the feedback to detect subtle wind changes and sail as efficiently as possible. These light-weight blocks feature a durable, UV stable acetal sheave that runs smoothly on a two stage system of low friction bearings. Acetal ball bearings handle moderate loads for high efficiency. As forces increase ball bearings can become distorted; shy of distortion a plain acetal bearing running on a stainless steel race shoulders the load keeping the ball bearings safe from damage while maintaining low friction. Fiber reinforced nylon cheeks provide rigidity and strength and are beefed up 316 stainless steel load straps. The included shackle features a pin with a low-profile head to prevent snagging on smaller lines. Get the subtle messages your boat sends you though the lines by using efficient and smooth Ronstan series 20 blocks.

This 20mm cheek block is well suited for running line along the deck and other flat surfaces. Commonly used in down-haul systems, barber-haulers and travelers these blocks can be used in conjunction with angled mounting pads to offer better line scope.

Key Features

  • Light weight blocks designed for moderate to high static and dynamic loads
  • Ideal for hand-held control lines
  • Unique two stage bearing system:
    • Acetal ball bearings deliver efficiency for moderate loads
    • Sliding acetal bearing on stainless steel race handles high loads and maintains low friction
  • Fiber reinforced nylon cheeks to add strength while reducing weight
  • UV stable acetal sheave is strong and light-weight
  • 316 stainless steel load straps add strength
  • Ideal for:
    • Travelers
    • Down-haul systems
    • Barber-haulers
    • Running control lines along flat surfaces

Ronstan Selection Guide

Sheave Diameter Line Compatibility
20mm 1/4" (6mm)
30mm 5/16" (8mm)
40mm 3/8" (10mm)
50mm 1/2" (12mm)
Ball Bearings Stainless Steel
Becket No Becket
Diameter 1/4 Inch or 6 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Mechanical Fasteners
Ratchet Non Ratcheting
Safe Working Load 550 Pounds
Type Single Cheek/Foot
Weight 0.4 Ounce
Sheave Diameter 20 mm