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105mm Synchro Single Block Clearance

105mm Synchro Single Block


Model # 3381068 | Mfg # 29921051
Limited availability.

Synchro blocks combine geometry, sheave ratios and a unique Free Spin bearing, to deliver performance that’s comparable to ball and roller bearing blocks used in pro racing at a more affordable price.

With conventional blocks, one of the biggest losses in efficiency comes from the distortion of line as it wraps around the sheave. Synchro blocks provide the optimal ratio between line size, sheave diameter and the interface between rope and sheave. The result is larger sheaves with a smaller axle than exist on conventional blocks. To help ensure that the benefits of design translate into improved performance, optimal line sizes are marked on sheaves.

Synchro blocks improve efficiency by nearly 5% on a single block at a load of 442lb. (200kg). Calculated over a typical six-block mainsheet system, this approaches a 40% improvement over conventional blocks.

This range of blocks transforms performance, not only by improving efficiency, but also speed and handling. Optimized block geometry, a revolutionary Free Spin bearing and a self-aligning head combine to reduce friction. Each component is synchronized with the movement of the line providing an easier, smoother transfer of power from deck to sail, and all with less line wear.

  • Sheave: Reinforced plastic
  • Sheave Size: 4-13/16"
  • Ball Bearings: Composite bearing
  • Cheek Material/Finish: Stainless steel and plastic
  • Shackle/Strap Type: 15° swivel
  • SWL: 7700lb.
  • Line Diameter: 5/8"
  • Line Size: 9/16"
  • Maximum Rope Size: 5/8"

105mm Synchro Single Block

Becket No Becket
Diameter 5/8 Inch or 16 mm
Direction Any
Integral Cleat No Integral Cleat
Mount Type Swivel Shackle
Ratchet Non Ratcheting
Safe Working Load 7700 Pounds
Sheave Diameter 105 mm
Type Single
Weight 27.51 Ounces

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