Change in the length of my rope after use - Petzl Belgique

Change in the length of my rope after use


  • Carefully read the Instructions for Use used in this technical advice before consulting the advice itself. You must have already read and understood the information in the Instructions for Use to be able to understand this supplementary information.
  • Mastering these techniques requires specific training. Work with a professional to confirm your ability to perform these techniques safely and independently before attempting them unsupervised.
  • We provide examples of techniques related to your activity. There may be others that we do not describe here.

It is important to know that your rope will get shorter with age, for two different reasons: 

  • You cut off one or two ends of the rope because they were damaged.
  • The rope shrunk. With age, the rope swells in diameter and thus shrinks in length. You may notice shrinkage of 2-3 % after the first few uses, and up to 10 % over the life of the rope.

Note also that this phenomenon is not necessarily symmetric on each end of the rope: half of the rope can shrink by 5% and the other half by 10%. In this case, the rope's middle mark is no longer in the correct location.

Shrinkage is more pronounced if the rope gets wet and then dries without being tensioned (climbing a snow slope, for example).

To limit this shrinkage, we advise you to:

- regularly alternate the use of the two ends of the rope.

Regularly alternate the use of the two ends of the rope.

- for half ropes, be sure to alternate the use of the two strands of rope. 

Finally, knowing that your rope can shrink over time, we recommend that you: 

- regularly inspect the middle mark of the rope. 

There is a simple way to find the middle of the rope: hold the two rope ends together, then slide the two strands simultaneously through your hands until the middle of the rope is reached.

Regularly inspect the middle mark of the rope.

- regularly evaluate the length of your rope.

- read the following tip Rope too short: warning - danger.