Forces in slacklining, on ratchet lines

The forces in slacklining that occur during the practise are composed of the preload force and the weight of the slackliner. This can be both static and dynamic. It is not possible to determine the forces without measuring device exactly – but one can calculate the forces in static slacklining with a formula approximately.

Here are some basic rules of the forces:

• The longer the slackline, the lower the forces on the end points (with the same preload)
• Slacklines with low elongation (static bands) cause higher forces on the endpoints
• The highest force peaks are reached in the middle of the slackline.

Measured values of forces in slacklining

In order to determine the actual force values, we have set up a SLACKTIVITY Experience Slackline at 2kN, 4kN & 6kN (1 kN = 100 kg) pretension. A 58 kg slackliner stood on this 11 m long slackline, rocked a lot and finally made a butt bounce. The measured force values in kN are listed in the following table.

Measurements in Video Form

Since the forces in slacklining vary according to preload, length and use, we have compiled six videos that shed light on each aspect of the force. Among other things, it explains how the forces act on the material and how they are calculated. What is the length of the slackline for impact? At which preload does the greatest force arise? Answers to these and other questions can be found in the following videos. Have fun!

Forces in Slacklining 1 – Static forces and pre-tension

This video shows the simple calculation of the static force and what to look for in dynamic force measurements.

Forces in Slacklining 2 – Shape of the forcecurve

What does a force curve look like in simple balancing and jumps? This video will explain this question.

Forces in Slacklines 3 – Different in length

This video explains how forces change at different slackline lengths. The greater the pretension, the greater the force.

Forces in Slacklines 4 – Force comparison with different pretensioned slacklines

Forces in Slacklines 4 – Force comparison with different pretensioned slacklines.

Forces in Slacklines 5 – More persons on a slackline

Here is shown how the forces change when several people are on the slackline.

Forces in Slacklining 6 – Trick combinations

Forces with different trickline tricks. 

You may also want to read: Forces in Highlining…

Writte by:

Samuel Volery

SLACKTIVITY Slacklines co-founder, managing partner and team athlete, Samuel Volery olds multiple highline world records (1900m – September 2019) and has a spectacular and versatile style when performing highline-shows.