Paragliding lines shrink with the use.
- Does anyone have a proper technique to stretch the lines?
- And about how many hours of flight we should do this?
I started looking for these data in the web, but I didn’t find yet a description of the method to do it.
Locally, some guys do the following:
- They fix both risers to a hook and apply 15kgs with dynamometer (or they hang a 15kgs item through pulleys) to the twins extremes of the cascade (I mean the lines to the left and right sides of the wing, for they should be identical), where the cascade is attached to the intrados. They apply the force with gloves in both hands, just before the attachment loop. They check that after the pull BOTH twins lines are identical in length. They never stretch the commands cascade (obviously).
- Timing used for this operation is about 200 hours of flight.
Personally I never did this, and to me it is not logical to apply the same weight to whatever diameter of lines… along the cascade the diameters are changing!!
Another issue is the number of cycles of load… the lines closer to the risers receive many cycles in one stretching operation (on the other hand, those are the thicker lines of the cascade…)
Comments and critics are welcome!!