You will need a good clean run, clear of trees, branches, bushes and any other obstructions so that the user can't hit into anything.

You will need strong anchor points, ie. Trees or poles

New unused poles to the specifications / standards of utility poles are ideal.

Trees should be living and healthy and in solid ground. They should also be growing straight up or angled away from the direction of the wire rope.

An arborist, or someone who knows their trees should be consulted if you are in doubt of the stability, health or strength of your trees. It is also important to preserve the health of anchor trees, padding of the cable will be necessary to protect your trees.

Guy cables transfer the horizontal load into a compressive load, pushing anchor trees and poles down instead of sideways.

Guy cables are required when using poles. They can be anchored to the base of appropriately located trees or underground anchors. To be on the safe side make your guy cable anchors strong enough to support a pull-out force of 2 x the maximum intended loads.

Guy cables should be in a direct line opposite the primary cable and strong enough so the required safety factors (5:1), wll is not exceeded.

For more information download our Guy Cable Length Calculator.xls

Cable / Wire rope

7 x 19 Galvanised Aircraft Cable is recommended for flying fox zip lines The rope construction is the best match for the operating conditions. It is hard wearing and extremely flexible. Stainless steel wire rope is more brittle and up to 10% weaker than galvanised and will not last as long.

Correct cable installation is one of the most important tasks to achieve.

You need to ensure that the wire rope has the correct sag (aka deflection) so the safe working load is not exceeded. Sag affects the amount of tension in the cable and anchor points as well as the speed and height the users travel above the ground.

Figures are theoretical in nature and the factor of safety is based on cable manufacturers recommendations

A 5:1 factor of safety is applied to the configured strength of the system to establish the working load limit. The configured strength is the systems weakest component.

i.e. 10mm - 7x19 Galv. cable with a breaking strength of 6500kg…… 6500 x 0.2 = 1300 kg WLL

Cable has a rated tensile strength reduction of 20% due to cable clips deforming the cable according to cable manufacturers

i.e. strength reduction of 20% applied to 10mm 7x19 Galv cable …1300 x 0.8 =1040kg WLL.

Why the big safety factor?

Safety factors are based on manufacturers  recommendations. 5:1 safety factor is based on "static loads".

Over time, wear and tear will weaken the cable. Safety factors are designed to ensure the cable is safe for its service life, they are based on the breaking strength of new unused cable.

When a steel beam fails it doesn't just break and fall down. It will start bending, deflecting, twisting. It goes through several steps warning that something is wrong - giving you time to react.

When wire rope fails there is no warning or time to react, there are no reserves, fail is a sudden now two pieces.

You need to ensure that the wire rope has the correct sag so the safe working load is not exceeded.

Sag (or deflection) is the distance the wire rope hangs down in the centre when weighted, measured as a percentage of the total length of the wire rope. Sag is integral to the strength and safety of the installed wire rope. The tensions in the line increase dramatically as the angle of the line under load increases, e.g. The tighter the rope (less sag), the greater the load on the entire system.

Tested to Destruction

Silly Fish

Flying Foxes are lots of Fun…but… Disregard for common sense and safe practices can be very painful!

destruction test turnbuckle destruction test wire rope clip

Our Flying Fox kits are intended for the more experienced NZ DIYers with the ability to safely construct and apply adequate cable safety factors, as detailed in our construction guide. As well as operate, inspect and maintain to an acceptable level for safe use.

If you intend constructing:

A Flying Fox for any commercial purpose or public use

A Flying Fox with unrestricted access and no supervision

Or if you are unsure or if there is any doubt regarding the strength, safety or integrity of your Flying Fox you must consult with an engineer or qualified professional who has experience working with steel cable, or at least seek similarly competent assistance!

We ride, push to the limit, test to destruction and inspect every component to ensure it is safe.

The installation, ongoing regular inspections and the way you use your flying fox is just as important as the equipment when it comes to safety.

Tension in cable with 3% sag

Tension in cable with 5% sag

Tension in cable with 10% sag

30 metre cable with a 100 kg static load

875 kg

527 Kg

267 Kg

Start Termination point height

Incl. In construction guide

End Termination point height

Incl. In construction guide

Detailed construction guide is supplied as part of our Flying Fox Kit and is not available separately

Disclaimer: Flying Fox Kit safety guarantee. View here

Recommended user weight limit for 10 mm cable:

120 kg with a minimum cable sag of 5%

Cable sag of 8% to 10% is recommended for public use.

Recommended user weight limit for 6.5 mm cable:

75 kg minimum sag 6%

85 kg minimum  sag 7%

100 kg minimum sag 9%

Minimum cable sag allows for dynamic loading created when hitting rubber end stop or bouncing on the cable.

Dare 2 Play Flying Fox

You don’t have to be a Dare-Devil…… just hold on tight for some serious fun!


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