Code Zero Furlingsets

What accessories do I need?

Key elements of a code zero system, in addition to the drum and swivel, are: Torsional cable, Furling line for the drum, Double fairleads

However, there are other accessory options for the drum and swivel but the requirement for these depends on your setup. Key considerations are:

• A purchase system / tack line under the drum allows you to easily bring the furler back to the bow to change sails (with a fixed bowsprit) and also allows fine tune luff control. Most manufacturers produce 3:1 friction sheaves which attach to the bottom of the drum

• 2:1 Halyard blocks – on very small boats (<35ft) you can get away with a 2:1 halyard shackle but most manufacturers produce their own 2:1 blocks which attach to the spindle on the top of the swivel for use with a 2:1 halyard 

What is the best code zero furler set up

Simplest – code zero drum attached to bowsprit with snap shackle, 1:1 halyard. Performance – code zero drum attached to bowsprit with snap shackle, 2:1 halyard improves luff control and reduces rig compression. Grandprix – Halyard hoisted into a halyard lock which removes mast compression, drum on a 3:1 purchase system for luff tension control.

Can I use a code zero furler for a staysail and what are the setup options for a furling staysail

Yes, it is common to use the same style continuous line furler for a furling staysail around a torsional furling cable. Whilst, in theory, it would be possible to use the same furler, most customers prefer to have a dedicated staysail furler so the staysail can be left in situ and even used at the same time as the code zero. In terms of size – in is considered sensible to use the same size furler for both code zero and staysail. Working loads are generally lower on a staysail but using the same size allows some redundancy in your furling systems. I.e. in the event of damage to either furler, or swivel, they can be interchanged.

Staysail setup options

More detail on staysail setup options can be found in this blog staysail setup. In general terms it is the same as code zero setup

• Simplest – code zero drum attached to bowsprit with snap shackle, 1:1 halyard
• Performance – code zero drum attached to bowsprit with snap shackle, 2:1 halyard improves luff control and reduces rig compression

• Grandprix – Halyard hoisted into a halyard lock which removes mast compression, drum on a 3:1 purchase system for luff tension control

Is the torsional cable included with the furler?

No – the majority of furler manufacturers do not supply a torsional cable with the furler. Most manufacturers supply furling thimbles designed for use with torsional rope, which can be fitted by an end customer using cable clamps to terminate the torsional rope.

What size furler do I need for my boat

There are many factors involved in identifying the right size furler for you needs. The starting point for a code zero is Safe Working `load (SWL) of the system. Any recommendations, based on boat length, are generic, usually based on a medium displacement monohull. But then your system choice can be refined basedon various other factors including sail type/size and sailing style. 

Key Brands in Code Zero Furling Systems

Upffront offers a curated selection of code zero furling sets from some of the most technically respected brands in the performance sailing industry. Each brand brings unique strengths to the table, tailored for varying requirements from cruising to Grand Prix-level racing. Choosing the right system involves understanding each manufacturer's approach to materials, mechanical design, and compatibility with specific rigging setups.

Harken

Harken has long been regarded as a reliable choice in the offshore and inshore racing communities. Their Reflex furling systems use a unique drive unit and torque transfer bearing system that enhances furling smoothness and reliability. Reflex kits often include a quick-release modular drum and a high-efficiency top swivel, making them well-suited for sailors seeking repeatable furling performance in high-load applications. Harken systems typically support 2:1 halyard attachments and include options for integrating purchase sheaves at the tack for advanced luff tension control.

Karver

Karver is known for its innovation and light weight, particularly among performance multihull and racing monohull sailors. Karver’s KF range is modular, enabling upgrades and customization based on rig requirements. Their systems feature minimalistic, low-friction hardware such as lash eyes and soft shackle compatibility, favouring weight reduction and mechanical simplicity. Karver also integrates features like ceramic bearings for durability under high torque loads, and their swivels are some of the most compact on the market, ideal for minimizing stack height.

Profurl

Profurl offers a more traditional approach but remains a mainstay for reliability and serviceability. Their Spinex systems, built specifically for top-down furling, are adaptable for code zero applications with straight-luff sails when combined with the appropriate torsional cable. Profurl systems are frequently chosen for cruising and bluewater applications due to their robust anodized construction and accessible spares support network. While less oriented toward high-performance regattas, Profurl remains a dependable brand with wide-ranging compatibility and sensible price points.

Ronstan

The Ronstan continuous line furlers are engineered with a strong focus on user-serviceability and strength-to-weight ratio. With sealed stainless steel bearings and a forged aluminum body, they strike a balance between durability and weight-conscious design. Ronstan’s offering includes high-load top swivels and efficient furling drums with good line grip characteristics, making them a dependable option for moderate performance applications and coastal cruisers upgrading from simpler furling gear.

Ubi Maior

Ubi Maior Italia stands out with its aerospace-grade build quality and beautifully machined components. Their furling systems are especially popular in the Grand Prix racing segment, featuring top-end materials such as titanium load-bearing elements and optimized for minimum weight aloft. Ubi Maior furlers are often paired with halyard locks and soft attachments, and their modular design supports sophisticated setups including 3:1 tack purchase systems and integrated locking features. This brand is highly recommended for custom race boats and high-performance monohulls or multihulls.

Selecting the right code zero furling system depends heavily on your sailing style, rig configuration, and load requirements. While Harken and Profurl may appeal to cruisers and offshore sailors for their robustness and support, Karver and Ubi Maior serve the racing community with technical refinement and modular versatility. Ronstan provides a versatile middle ground, offering value without compromising essential performance features.

For a deeper dive into furling system sizing, halyard setup, and rig integration, consult the Code Zero & Gennaker Furling Guide. Upffront’s sailing experts are available to offer guidance tailored to your boat and sailing goals.