To convert a Profurl NEX Code Zero furler into a SPINEX top-down furler you need four purpose-built components: an anti-torsion cable, Profurl Sail Bearings, anti-torsion clamps, and a Torlon-bearing tack swivel. Fitted together, these parts let the same drum unit furl an asymmetrical spinnaker or gennaker from the top down instead of a straight-luffed Code Zero.
NEX vs. SPINEX conversion at a glance
| Component | Purpose | Why it matters for top-down furling |
|---|---|---|
| Anti-torsion cable | Links tack and head with minimal torsion loss | Transmits furling rotation up the luff; needs high torsional stiffness, low weight, and flexibility |
| Sail Bearings | High-density spheres that spin around the cable | Protect light spinnaker cloth from the faster-spinning cable and prevent jamming |
| Anti-torsion clamps | Cable end fittings with thimble | Provide quick installation; the bottom clamp integrates with the tack swivel |
| Tack swivel | Torlon-bearing swivel with D-shackle | Lets the sail furl progressively from the top down without jamming |
What is the difference between a NEX and a SPINEX furler?
The Profurl NEX is a Code Zero furler built for flat, torsion-resistant sails with a straight luff. The SPINEX is a top-down furler designed for asymmetrical spinnakers and gennakers, which are light, full-shaped sails that must be furled from the head downward. Both share the same drum unit, so a NEX can be upgraded to SPINEX with the correct top-down kit rather than buying a second furler.
What are the four conversion components?
The anti-torsion cable ensures the link between the tack and head with minimum loss of torsion. Good anti-torsion cables are lightweight, have significant torsional stiffness, offer great flexibility for easy handling and storage once furled, and provide sufficient load capacity.
Because asymmetric spinnaker cloth is both light and fragile, the anti-twist cable tends to damage it, and the cable spins faster than the sail during furling, which can cause the sail to jam. Profurl's Sail Bearing Technology solves this with high-density spheres that spin freely around the anti-twist cable to protect the sail from the cable.
How does the tack swivel enable top-down furling?
Fitted with Torlon bearings, the tack swivel makes it possible to furl the sail from the top downward, progressively stifling the sail without creating a jam. It also comes with a D-shackle for securing the spinnaker tack to the tack swivel. The anti-torsion clamps use cable end fittings with a thimble for quick, easy installation, and the bottom clamp is integrated directly with the tack swivel.
Which conversion kit should I choose?
At MAURIPRO Sailing we offer kits made specifically for each Profurl NEX furler unit, from size 0.9 up to 6.5. Choose the kit that matches your existing NEX unit size, and it will include everything needed to adapt the unit to your gennaker or asymmetrical spinnaker and convert it into a SPINEX top-down furler with Profurl's unique Sail Bearing technology.
Frequently asked questions
Can I convert my Profurl NEX into a SPINEX without a new furler?
Yes. The NEX and SPINEX share the same drum unit, so you only need the top-down conversion kit — an anti-torsion cable, Sail Bearings, anti-torsion clamps, and a tack swivel — matched to your NEX size.
What does Profurl's Sail Bearing technology do?
It places high-density spheres that spin freely around the anti-twist cable, protecting the light, fragile spinnaker cloth from the faster-spinning cable and preventing the sail from jamming during furling.
What size conversion kit do I need?
Match the kit to your existing NEX unit size. Kits are available for every NEX unit from 0.9 through 6.5.
Why does a spinnaker need top-down furling instead of a standard Code Zero furl?
Asymmetrical spinnakers and gennakers are light, full-shaped sails. Furling them from the top downward with a Torlon-bearing tack swivel lets the sail collapse progressively without jamming, which a straight-luff Code Zero furl cannot do.
What is the anti-torsion cable for?
It links the tack and head with minimum torsion loss, transmitting the furling rotation up the luff while staying lightweight, torsionally stiff, and flexible enough for easy handling and storage.
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