Code 0 cables

Code zero cables differ from top-down gennaker cables

For these straight luff, upwind sails, there are two key features of a code zero cable. You want high cable tensile stiffness plus strength, to ensure you can maintain a straight luff. Then you want the diameter to be as small as possible to reduce windage at your leading edge.

The smaller the diameter, the lower the torsional stiffness of the cable, therefore, despite its high price, PBO generally offers the best performance characteristics for a code zero cable. This is one of the stiffest, strongest fibres available on the market and therefore you need less core fibre in the cable to achieve your tensile stiffness-strength criteria. That in turn provides opportunities to have more braided covers to increase the torsional stiffness of the cable relative to its diameter, compared to a cable with a fatter core and just 2 braided covers.

How are code zero torsional cables made?

All our custom torsional cables, regardless of manufacturer, are built using the technique of endless winding uni-directional core fibre. Two furling thimbles are set up on each end of a winding bed and then a single tow of core uni-directional fibre (generally PBO, K49 or Dyneema®) is wound around the ends to form a loop of fibre. Once the required core fibre content is reached, to deliver the strength and stiffness, the core fibre is normally run through a taping machine (to compact the core fibre together and create a uniform shape), before going through multiple passes of a braiding machine. After each pass of braid, a layer of flexible resin is applied which bonds the braided layers together to improve torsional stiffness.

What are important considerations when buying code zero cables

For a grand prix racing code zero cable, PBO would still generally be the highest performing option for core material. However, in a serious blue water offshore cruising scenario, where weight and windage play less of a role in the decision making process, Kevlar provides a very stiff, long lasting cable. However, since the introduction of SK99 as a core material, this provides performance specs close to PBO but with much higher longevity / durability, at a reasonable price point, and our starting point at Upffront will usually be an SK99 cable. 

How do I find the right code 0 cable for my needs?

Our selection of custom code zero cables are based on generic specifications. Club racers and cruisers should be able to find a suitable cable for their needs amongst our large standard range. First step is to identify the approximate cable length you require. Then you will be offered x3 core material choices (PBO/K49/SK99) – see here a comparison between x3 17.5m cables. The most important thing to check initially is compatibility of the cable fittings with the jaw width and jaw pin diameter of your furler. Then you can double check Safe Working Load (SWL) of the cable relative to the SWL of your furler and then weigh up relative pros and cons of diameters vs weights and price.

Cable specification is a complex business and we are more than happy for you to contact us to discuss your project and look at detailed specifications. To get develop a custom spec we need to know more details about your boat and sail design. Here are a list of questions we will ask if you would like help with your cable spec:

• Boat Make / Model
• Cable length
• Furling type: Top-Down / Bottom-up
• Style: Free-flying / Luff Pocket
• Furling unit Make / model / SWL
• Sail type
• Sail area
• Max App Windspeed

Feel free to contact us for a dedicated quote or help with cable specification.