HARKEN MKIV Unit 1 Furler

Make headsail deployment and storage easy. 

Improved systems enable racers and cruisers to furl or reef using independent head and tack swivels to maintain great sail shape for optimal speed. Built for longevity, ease of use and simplicity of installation. Strong, lightweight, and aerodynamic with a twin-groove foil and smooth feeder for fast hoists, douses and sail changes. Multiple computer-designed stacked races of Torlon® ball bearings in high-load areas. Large-diameter drums increase mechanical advantage. Free-spinning, high-strength halyard swivel reduces weight aloft. Strong foil joints are easy to assemble without cutting your headstay. Hardkote anodized aluminum line guard, torque tube and swivels, tough polymer resin drum cap. Swage, rod, Norseman® or Sta-Lok® terminals required. Fits #6 luff tapes. Extra 7′ extrusions and connectors are available for longer headstays.Designed for easy installation, with drums that install over existing turnbuckle. Units 0, 1 and 2 for boats from 22′-46′.

Key Features 

• Easy to use and install and built tough for long lasting performance
• Twin grooves and smooth feeder allow fast hoists, douses and sail changes
• Multiple rows of free-rolling Torlon® ball bearings minimize friction for smooth sailing
• In high-load areas, computer-designed stacked bearing races and large-diameter drums offer smooth reefing and furling
• Independent head and tack swivels shape the sail when partially furled
• Strong foil joints withstand years of torque loading and are easy to assemble
• Small diameter torque tube with tapered top ensures the furled sail has a smooth, compact shape
• Deep-saturation Hardkote anodized line guard, torque tube and swivels for strength and durability
• Removable split drum comes off easily for racing
• Stainless feeder allows easy hoisting and sail changes
• Double grooves for racing sail changes
• Fits #6 luff tapes
• Ideal for club racing

Installation is easy: C-shaped open connectors with low-friction plastic isolators slip onto the headstay wire and into the foil without the need to cut your headstay. The foil’s twin grooves and smooth feeder allow fast hoists, douses, and sail changes—ideal for club racing. The drum install over the existing turnbuckle and is adaptable to a variety of rigging options. The Harken toggle assembly accepts standard turnbuckles using swage, rod, Norseman or Sta-Lok terminals, or fits directly to a marine eye and the turnbuckle body is accessible for adjustment by raising the drum.

The controlling dimensions for sizing Harken furling systems are headstay wire diameter and clevis pin diameter. Measure your boat’s headstay length to determine whether a standard package has enough foils to build the unit.

• Choose Unit 0 for boats 22’–30′
• Choose Unit 1 for boats 26’–36′
• Choose Unit 2 for boats 36’–46′

Specifications 

MKIV Unit 1

For boats 28′ to 36′ and headstay lengths from 45’11” to 52’7″.

• Boat Size: 28′ – 36′ (8.3 – 11m) 
• Headstay Length: Standard 45’11” (13.99m); Max. 52’11” (16.12m) 
• Headstay: Wire: 1/4″, 9/32″ (6, 7, 8mm); Rod: -8, 5.72mm, -10, 6.35mm 
• Pin Diameter: 1/2″ (12.7mm) 
• Headstay Extrusion: Aluminum aerodynamic Air-Foils® 
• Grooves: Double grooves for racing sail changes 
• Drum Material: Hardkote-anodized aluminum; drum cap engineered from super-tough polymer resin 
• Head Swivel Material: Hardkote-anodized aluminum 
• Attachment Method: Swage, Rod, Norseman® or Sta-Lok® terminals required; toggle flips for fork or tang chainplate installation 
• Ball Bearings: Torlon® bearings in high-load areas