New Products: Harken Single-Acting Integral Backstay Adjuster

SinC Harken Backstay Adjuster

May 4, 2022

It’s one of the best things about sailors: we hate to give up on our equipment. But if you’re like a lot of owners of boats with vintage integral hydraulic backstay units, you’ve been putting up with seepage and slippage for too long. We’ve introduced our new integral hydraulic unit to convince you it’s finally time to pull the pins on that leaker and start anew.

Unlike some competitive units, you’ll notice the Harken Single-Acting Integral Backstay Adjuster has no external hydraulic hoses to snag dock lines or lazy sheets and come loose. As you pump the handle, the single-acting pump pushes fluid through a hole gun-drilled inside the stainless rod, to top of the cylinder, creating pressure and backstay tension. A simple pressure-release knob releases that pressure, reducing mast bend. All the fluid stays inside the tube all the time.

Harken’s integral hydraulic backstay adjuster provides the power to optimize sail shape quickly for racers and adjust mast tension for smoother furling for cruisers.

The cylinder features a built-in, single-acting pump. Every unit includes a hardcoat-anodized aluminum cylinder and pump, valve, and stainless pump handle with two attachment options: 1) a roll pin, that when installed, locks the handle permanently, 2) the roll pin can be left off and the handle may be inserted when needed, but stored separately.

SinC Harken Backstay Adjuster 2 400Cylinders include a clevis pin on both ends. A fiberglass position indicator attached to the top clevis pin slides down the cylinder as it’s retracted for repeatable tension settings. Standard eye-jaw toggles fit all Harken cylinders and are recommended on all installations.

The pressure-release knob turns clockwise to close and pump, counter clockwise to release. When closing the pump, the knob cannot be over-tightened by hand, preventing damage to the valve. Release speed depends on how far open the knob is turned. Pressure relief is factory set to prevent crew from over-tensioning the backstay.

The new Harken Integral is designed to be bulletproof and need no nursing for years. That pressure-release knob cannot be over-tightened. Turn it clockwise to close, counter clockwise to open. A very analog, very pragmatic position indicator completes the offering — to make duplicating settings fool-proof.

Harken integral backstay adjusters come in four sizes to fit boats 9 – 18 m (30 – 60′) with stay diameters of 5 – 10 mm (7/32 – 3/8″).

Watch this video for the inside scoop:

{youtube}EaYfUvQlcbI{/youtube}

Related Articles

  • SailGP: NorthStar Has Some Moments at Bermuda Sail Grand Prix

    SailGP: NorthStar Has Some Moments at Bermuda Sail Grand Prix

    May 14, 2026 The Canadian team demonstrated progression on Saturday finishing 2nd, 4th, 5th and 8th, yet struggled a bit on Super Sunday with 12th, 12th and 4th place finishes. Improved starts helped the the team remain in contention across the fleet during seven races over the weekend. “I’d summarize the day as frustrating. If… Read More…

  • Sail Canada Welcomes The Government of Canada’s Historic Investment in Sport

    Sail Canada Welcomes The Government of Canada’s Historic Investment in Sport

    May 14, 2026 Sail Canada welcomes the Government of Canada’s historic investment in sport announced in the 2026 Spring Economic Update. The federal government’s $755 million investment will expand access to sport and strengthen support for Canadian athletes from grassroots to high performance. Sail Canada thanks Prime Minister Mark Carney and Secretary of State for Sport Adam… Read More…