When to re-line...

[Gawain 0]

My Triathlon has about 330 jumps total on it. The lines (Spectra 825/Toggle lines: Dacron 525) "look", and "feel" great, but they seem to be showing some stress by subtle differences in "sag" when I'm packing and stowing. There's no significant fraying (the Dacron is a wee bit), and I want to know what else to keep an eye open for, or just get it re-lined and move forward....thanks...

[freeflir29 0]

Disclaimer: I'm no rigger
But here's my .02C The only reason to reline a canopy is if it
A) Shows significant wear on the lines. Fraying usually.
or
B) Is out of trim. If there isn't more than 2-3 inches difference in the two lines it should be fine. Easiest way to check is just to compare all the lines. IE...outside A, B, C, and D lines. Then move inboard from there. In fact I usually just check the outside lines because they get the most wear and shrinkage. If they are OK the inboard lines should be fine too.
If it's in trim and the lines aren't frayed significantly I say don't waste your money.
"It's all about the BOOBIES!"

[Hooknswoop 19]

Before you can inspect your line set it is necessary to know what type of lines you have and what to look for. There are three different types of suspension lines currently in popular use: Dacron, Spectra, and Vectran, each having different properties and performance as well as different inspection and replacement requirements. If you’re not sure what type of lines you have, check your manual, consult your rigger, or call the manufacturer of your canopy.
Dacron is a white, thick, heavier-duty line. Dacron is found in three sizes; 600, 800, and 1000 pound tensile strength. It will stretch a little on opening, lessening opening shock. Over time, it will shrink from the heat caused by the friction from the slider descending the lines on deployment. Dacron tends to be used on larger canopies that are not sensitive to line trim so the lines will probably wear out before line trim becomes a factor. The extra drag from the thicker line doesn’t affect a large, slow canopy as much as they would affect a small, fast canopy. Dacron lines should last 800 jumps or more before the line set is worn to the point they need to be replaced.
Spectra is a common line found in different sizes based on their strength. It is a thin, flat, white line. Spectra comes in four sizes; 550, 725, 825, & 1000 pound tensile strength. Spectra is the most common type of line used on canopies. It doesn’t stretch on opening, transmitting all the opening forces to the jumper. It shrinks much quicker than Dacron, but isn’t as thick so it has less drag. On faster canopies, line drag becomes a factor, and the smallest Spectra, 550, is very thin and has very little drag. The thicker Spectra is usually used for the steering lines. A canopy lined with 550 Spectra will be out of trim before a canopy lined with 825 Spectra. A Spectra line set’s trim should become out of tolerances before a line breaks. Spectra usually lasts from 400 to 500 jumps, depending on the size of the line, before the line set is out of trim.
Vectran is the newest line (not anymore, HMA is). It is a thin, yellowish brown and comes in three sizes; 500, 750 and 1000 pound tensile strength. Like Spectra, it also doesn’t stretch on opening. Vectran is usually used on the small, faster canopies that are very sensitive to line trim. Vectran biggest advantage is that it doesn’t shrink from the heat from the friction of the slider. The down side of this new line is that it wears faster then other types of line. Vectran lines need to be replaced based on wear, not line trim. A Vectran line set should be replaced after 350 to 400 jumps.
Checking the condition and trim of your canopy’s line set is simple. Run up your lines from the container to the canopy the same as the beginning of a normal “PRO” pack. Inspect the lines as you go, looking for areas of wear indicated by fraying. Check the length of your steering lines with the brakes set. They should be exactly even. If they are not even, check to see if they are twisted. A twisted steering line will be shorter than a line that is not twisted. It is best to remove any twists from your steering lines each time you pack. A high wear area, (as I discovered), is near the loop for setting the breaks. As you fly the canopy, this area of lines is being pulled back and forth through the guide ring on the rear riser, causing wear. Stainless steel guide rings on the rear risers will reduce this wear because they are smoother than the zinc plated rings. When your canopy opens in brakes, the steering lines are under tension. Every time you release your brakes, you pull the tab (the stiff part of the toggle for setting the brakes) out of the loop. This “sawing” action results in tremendous wear on the loop, eventually causing it to break. Another high wear area is where the lines attach to the links. If the slider is allowed to flap as you fly your canopy, the grommets beat on the lines, causing wear. A simple solution is a collapsible (kill line) slider. Vectran is more susceptible to these types of wear than Spectra or Dacron. Your rigger can replace a single line that is fraying. Some riggers will replace entire line sets, but the manufacturer can replace a line set easier and in less than half the time it would take most riggers.
Stainless steel slider grommets and soft links will also increase the life span of your lines. A brass slider grommet impacting a stainless steel Rapide link will cause the grommet to dent and burr. Instead of having a smooth grommet sliding down your lines, the grommet will have a rough surface, wearing out your lines at a faster rate.
After inspecting your lines, gather up the nose cells as in a normal “PRO” pack, and making sure that your risers are even and your lines are taunt, compare the length of the “A” lines (the lines that attach to the nose of the canopy). Compare the difference in length of your outer “A” lines (the lines that attach to the end cells of the canopy) to your center “A” lines (the lines that attach to the center cell of the canopy). When the line set is new, the “A” lines are all the same length, except for a few canopies, (check your owner’s manual). As the canopy is jumped the outside lines will shrink faster than the inner lines (except with Vectran lines) because they are in contact with the slider grommets more than the inner lines. This uneven shrinkage affects the openings and performance of the canopy. If your outer “A” lines are shorter than the inner “A” lines, measure the difference with a ruler. Then check your owner’s manual or call the manufacturer of your canopy to find out how much the line set is allowed to shrink. If the line set is out of tolerances, send the canopy back and have the manufacturer replace the line set. I have had a line set replacement take as little as one week and as much as four weeks.
When you inspect the sections of line with another line “finger trapped” inside it, be careful. When the outer line frays, it can look as if the line is not in bad condition because the inner line makes the line thicker. But if the outer line breaks the inner line can slip out and the line will come apart.
Replacing the line set of your canopy is a part of the regular maintenance of your rig and will bring new life back into your canopy. A line breaking on opening can result in a cutaway and a line breaking at low altitude could be fatal.
Hook

[billvon 3,120]

>A canopy lined with 550 Spectra will be out of trim before a canopy
> lined with 825 Spectra.
I would also add one caveat about 550 lines - they are thin enough to hook behind grommets, especially the grommet used for the closing loop attachement. If you do use thin lines be sure to check the area in your pack tray for potential snag points like the above-mentioned grommet. Fliteline had a problem with this a little while back. A good rule of thumb is - if you can get your thumbnail under the edge of the grommet, it might be a hazard.
-bill von