Seldén Furlex 304S Jib Furling System

Furlex 304S Sizing and Kit Selection

The Seldén Furlex 304S is built around two forestay sizes: 8 mm and 10 mm. These are separate kit families with different maximum supplied wire lengths and different Seldén part numbers.

Boat length is useful as an initial guide, but the existing forestay diameter and required finished forestay length are the more important measurements when replacing a furling system. Seldén places the 304S broadly in the 35–45 ft yacht range.

304S Forestay Length Matrix

The 20.28 m / 10 mm standard Sta-Lok kit is selectable on this product. If the same forestay length is required with an integrated rigging screw, please contact us before ordering so the required configuration can be confirmed.

How to Specify a Replacement 304S

For an existing installation, first confirm the forestay wire diameter. The 304S options on this page are for 8 mm or 10 mm wire only.

Next establish the required forestay length. The lengths shown above are the maximum wire lengths supplied with each kit; the forestay is cut and terminated to suit the yacht during installation.

Finally, choose the lower-terminal arrangement. The standard kits use Seldén's Sta-Lok mechanical terminal. Where offered, the alternative kit incorporates an integrated rigging screw to provide forestay adjustment within the Furlex lower assembly.

304S Installation Considerations

Correct furling operation depends on more than selecting the right drum size. Forestay length, lower-toggle articulation, halyard lead, mast rake and the relationship between the sail and foil all need to suit the installation.

The 304S uses Seldén's twin-groove aluminium luff extrusion and stainless-steel bearing components. The forestay remains the structural stay while the Furlex foil and furling assembly rotate around it.

If an existing Furlex is being replaced, retaining the old forestay measurement, lower-terminal dimensions and tack position can make specification considerably easier.

Need a Different Furlex Size?

If your forestay is smaller than 8 mm or larger than 10 mm, see the Seldén Furlex 104S, 204S, 304S and 404S comparison to identify the appropriate system.

Martin Leaning Masts & Rigging can also help identify the correct Furlex from yacht model, existing rig dimensions or measurements taken from the removed forestay. Contact our rigging team if you would like the specification checked.