Harken 57mm Carbo Ratchamatic® Blocks | Plain Sailing Chandlery

Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to our popular Harken Big Boat blocks, these small, compact blocks have very high working loads for safe, easy trimming. Lightweight nylon resin sideplates replace stainless steel straps found in Classic blocks. Densely packed glass fibers reinforce resin for strength.

The Carbo Ratchamatic® is a load-sensing ratchet block that rolls freely in both directions under low loads and automatically engages the ratchet as loads increase. Shifting between ratchet and light-air modes is seamless. Standard grip: medium/light air; 10:1 holding power.

Power3 ratchet blocks provide sailors that race small one-designs with three holding-power options to handle a variety of wind and sea conditions. More choices allow sailors to fine-tune their set-ups in tandem with the purchase that provides the ideal level of power, responsiveness and grip. On/off switch operates from both sides.

The spring on the HTE (high-threshold engage) version of the 57 mm Carbo Ratchamatic blocks was made stiffer to delay the point where the ratchet engages, allowing the block to run free more of the time. The ratchet function engages at higher loads to allow the old kite sheet to run free for crisper gybes.

1.5x grip: breeze–on/puffs; 15:1 holding power

2x grip: big breeze/steady: 20:1 holding power

Sheave Ø (mm) 57 mm

Sheave Ø (in) 2 1/4 in

Maximum line Ø (mm) 10 mm

Maximum line Ø (in) 3/8 in