jonno 0 #1 February 13, 2015 Im seeking some well informed advice on line size. Im placing an order for a new PD Storm . Im at the point on the oder form where I need to decide on line. My options listed are 600 lb Dacron 550 lb Microline 825 lb Microline Edited - Thanks for all the advice here on line types. I'm decided on Microfine but I'm still seeking advice on what factors go into deciding 550 lbs or 825 lbs ? Can I get away with a presumably lower pack volume of 550 lbs line with my higher suspended weight of 220b + gear ? Quote Share this post Link to post Share on other sites
hackish 8 #2 February 13, 2015 Personally I'd do the microline. I don't like dacron because I find it too bulky. There are camps of thought on each line and each has its advantages and disadvantages. Searching will give you many pages of discussions. There are a lot of things that go into a hard opening so you are better off to invest your time in maintaining elastics, neat and proper packing and good stable deployment to lessen your chance of a hard opening to begin with. -Michael Quote Share this post Link to post Share on other sites
gowlerk 2,133 #3 February 13, 2015 If you go microline (which is merely PD's word for Spectra) go with the heavier 825 size. (my choice as well) The main advantage to the 550 line is lower drag. Not really a factor for you. If you don't mind the bulk of Dacron many people do believe it does contribute to softer openings. Others say bullshit. Make sure you have room for it in your container. And it will probably make it harder to resell, if that is important to you.Always remember the brave children who died defending your right to bear arms. Freedom is not free. Quote Share this post Link to post Share on other sites
Quagmirian 40 #4 February 13, 2015 Have you seen John LeBlanc's video about line types? Quite a useful summary: http://youtu.be/knXrXHiWO7o Quote Share this post Link to post Share on other sites
mcordell 2 #5 February 13, 2015 jonnoIm seeking some well informed advice on line size. Im placing an order for a new PD Storm . Im at the point on the oder form where I need to decide on line. My options listed are 600 lb Dacron 550 lb Microline 825 lb Microline Me = a 45 yr old reasonably fit but large framed 220b jumper with the aches and pains that go with being a middle aged old bastard. My understanding is the Dacron will have a elasticity which might help with my creaky old body but degrades faster than microcline. Im tempted by Dacron but if I go with Microline what size do I want? I'll go with lower volume if I can but what determines what line strength I need ? Thanks in advance :-) I would go with the 725 spectre (what pdf calls 825 microline). I do find It curious that they call it 825 when the supplier sells it as 725 and the spool says right on it tensile strength at least 725 lbs.www.facebook.com/FlintHillsRigging Quote Share this post Link to post Share on other sites
jonno 0 #6 February 13, 2015 QuagmirianHave you seen John LeBlanc's video about line types? Quite a useful summary: http://youtu.be/knXrXHiWO7o Thnaks Quagmirian , Yup Iv'e seen those , Im more interested in the differences in the line strengths at this stage and Im not finding much info on that. Quote Share this post Link to post Share on other sites
jonno 0 #7 February 13, 2015 gowlerkIf you go microline (which is merely PD's word for Spectra) go with the heavier 825 size. (my choice as well) The main advantage to the 550 line is lower drag. Not really a factor for you. If you don't mind the bulk of Dacron many people do believe it does contribute to softer openings. Others say bullshit. Make sure you have room for it in your container. And it will probably make it harder to resell, if that is important to you. Presumably the 550 means lower bulk too? is it an option for lighter suspended weights ? Would it not be suitable for me at 220lbs ? Quote Share this post Link to post Share on other sites
skydiverek 61 #8 February 13, 2015 jonnoIm seeking some well informed advice on line size. Im placing an order for a new PD Storm . Im at the point on the oder form where I need to decide on line. My options listed are 600 lb Dacron 550 lb Microline 825 lb Microline Here is what BILL BOOTH has said on dropzone.com about DACRON LINES. Great source of info!: "My tests show up to a 300% increase in opening shock felt by the jumper using Spectra vs. Dacron suspension lines. It is not always that much different. It depends on how quickly the force is applied...and canopy makers have done a good job of designing canopies that open slowly enough to allow the routine use of Spectra. However, when a rare hard (quick) opening happens, Spectra lines will definitely make it hurt more." "Anyone who doubts that suspension line stretch is a factor in reducing the opening shock felt by a jumper, should make a bungee jump...only replace the normal stretchy bungee cord with a stainless steel cable. What's going to happen when you hit the end of that steel cable? Your leg is going to be torn off, that's what. Now remember, Spectra line stretches about as much a steel cable." "If you are not using Dacron lines, they would help. They stretch a little, and also slow the slider down due to surface friction. Spectra (micro) line does not. If you are already using Dacron lines, and still having hard openings, get a canopy that opens slower." "The best way to avoid injuries from that occasional super hard opening (as well as the hard openings themselves), is not to jump no-stretch lines. Ask yourself, "Do I really need the (slight) advantages no-stretch lines offer?" If not, get Dacron. Your body will thank you, because even if you are not ever seriously injured on any single jump, each even slightly hard opening on no-stretch lines is damaging your body...and it all adds up." "Spectra (micro line), Vectran, Kevlar, and HMA are "no-stretch" lines. They do not "absorb" opening shock the way Dacron does. This means that the same "hard" opening can hurt you a lot more. It's like doing a bungee jump with steel cable. The same force is applied...but a hell of a lot more shock is felt by the jumper. All the opening shock caused broken harnesses (two PDF tandem harnesses recently broke), injuries (a guy just broke both femurs), and fatalities (4 in the last two years that I know of) have all been on "no-stretch" line canopies, and could probably been prevented if Dacron line had been used. No stretch line is used because it is thinner, lighter, and has less drag than the same strength Dacron. While this is an "advantage" in a high speed swoop, it has no place in tandem. 85 year old grandmothers jump tandem. They, and many other tandem students, need the softest opening shock possible. This is why we only use Dacron line on our tandem products. Not to mention that our tandem equipment was NOT drop tested with no-stretch lined canopies. I don't care if you have 1,000 jumps on a particular canopy with no-stretch lines with no problems. Ever canopy opens hard eventually. When that happens, I want some "bungee cord" between that canopy and the tandem passenger." "One thing is for sure, if you jump "no-stretch" lines, especially Spectra (because it's so slippery, and reduces slider drag) your chance of being injured or killed by a hard opening shock is much greater than if you jump Dacron line, which stretches just enough to absorb some of that shock before it hits you." "Spectra (or micro-line) is strong and tiny, so it reduces both pack volume and drag , which means you get a smaller rig and a faster canopy. Unfortunately, It has a couple of "design characteristics" (this is manufacturer talk for "problems") It is very slippery (less friction to slow the slider), and stretches less than stainless steel. This is why it hurt people and broke so many mini risers when it was first introduced. Now, I must say that the canopy manufacturers did a wonderful job handling these "characteristics" by designing new canopies that opened much slower than their predecessors. However, the fact still remains, that if you do have a rare fast opening on a microlined canopy, Spectra (or Vectran) will transmit that force to you (and your rig) much, much faster, resulting in an opening shock up to 300% higher than if you have Dacron lines. (It's sort of like doing a bungee jump with a stainless steel cable. At the bottom of your fall, your body applies the same force to the steel cable as it would to a rubber bungee cord, but because steel doesn't stretch, your legs tears off.)." "Reinforced type-17 webbing risers rarely break. They have a new breaking strength of around 3,500 lbs. This is not that much less than type-8 risers breaking strength of 4,000 lbs. The real difference is whether you have mini rings or large rings...and the difference here is in cutaway forces, not breaking strength. While properly designed mini-ring risers can easily release even a 250 lb. jumper in a 3 or 4 "G" spin, the problem is that it is harder to manufacture mini-ring risers correctly. What causes any riser to break is usually a combination of a heavy jumper, a hard opening canopy, and no stretch (Spectra, Vectran, or HTML) line. Broken risers on Dacron lined canopies are very rare indeed." "Single rear riser break is very rare. Risers usually break where they go around the large harness ring. It is obvious that since the "reinforcement" in type 17 risers is below the confluence, it does nothing to prevent this kind of damage. When this riser broke, it "released" a lot of energy, thus preventing much more serious injury of the jumper. Which is a good thing. The only way I know of to prevent "killer" opening shocks, is not to jump Spectra (Microline) or Vectran. They don't stretch at all, and therefore do nothing to help absorb the energy of a really hard opening. As long as we insist on jumping non-stretch lines, incidents like this are bound to happen. (Canopies with Dacron lines can still open hard, but much less shock is actually felt by the jumper.)." Quote Share this post Link to post Share on other sites
gowlerk 2,133 #9 February 13, 2015 QuotePresumably the 550 means lower bulk too? is it an option for lighter suspended weights ? Would it not be suitable for me at 220lbs ? Yes 550 is lower bulk. But not as much difference as the difference between Dacron and Microline. Any line that PD will install is strong enough for your weight. The heavier Microline will probably last longer, and may take slightly longer to go out of trim. I weigh about 200 and I get 600 jumps out of my 550 lined Stiletto. They don`t break, but the center ones stretch from the load, and the outside ones shrink from the friction of the slider. This results in the canopy going out of trim. It may matter less for you, depending on how heavy you load your Storm.Always remember the brave children who died defending your right to bear arms. Freedom is not free. Quote Share this post Link to post Share on other sites
GLIDEANGLE 1 #10 February 14, 2015 If your container has room... get the dacron so that you can do CReW with your Storm!The choices we make have consequences, for us & for others! Quote Share this post Link to post Share on other sites
gowlerk 2,133 #11 February 14, 2015 GLIDEANGLEIf your container has room... get the dacron so that you can do CReW with your Storm! That's right! I never thought of that. On a Storm Dacron lines may be an easier resale feature.Always remember the brave children who died defending your right to bear arms. Freedom is not free. Quote Share this post Link to post Share on other sites
RMURRAY 1 #12 February 14, 2015 too bad you cannot get vectran or hma. if you go with spectra do NOT go with the 550. can go out of trim in no time. Quote Share this post Link to post Share on other sites
riggerrob 615 #13 February 15, 2015 Agreed! 550 versus 825 Spectra makes a minor difference in pack volume, but 550 lasts half as long. I recommend 825 Spectra to most sport jumpers. Quote Share this post Link to post Share on other sites
Hellis 0 #14 February 15, 2015 mcordell***Im seeking some well informed advice on line size. Im placing an order for a new PD Storm . Im at the point on the oder form where I need to decide on line. My options listed are 600 lb Dacron 550 lb Microline 825 lb Microline Me = a 45 yr old reasonably fit but large framed 220b jumper with the aches and pains that go with being a middle aged old bastard. My understanding is the Dacron will have a elasticity which might help with my creaky old body but degrades faster than microcline. Im tempted by Dacron but if I go with Microline what size do I want? I'll go with lower volume if I can but what determines what line strength I need ? Thanks in advance :-) I would go with the 725 spectre (what pdf calls 825 microline). I do find It curious that they call it 825 when the supplier sells it as 725 and the spool says right on it tensile strength at least 725 lbs. I have read, so it could be wrong, that they call it 825 because it's 725 coated or somehow treated line Quote Share this post Link to post Share on other sites
mcordell 2 #15 February 15, 2015 QuoteI have read, so it could be wrong, that they call it 825 because it's 725 coated or somehow treated line The line comes from a singular supplier called CSR Braids out of Sellersville PA. They buy the spectre yarn directly from the manufacturer and are the global supplier for Spectre braided line. PD and every other manufacturer order directly from CSR in bulk quantities (200,000 feet or so). The line is never treated or coated again. That's why it is so interesting. 825 microline and 725 spectre are the exact same product. The spool says "at least 725" so my best guess is that PD pull tested it to 825 and that's where they got their number.www.facebook.com/FlintHillsRigging Quote Share this post Link to post Share on other sites
riggerrob 615 #16 February 15, 2015 .... 825 microline and 725 spectre are the exact same product. The spool says "at least 725" so my best guess is that PD pull tested it to 825 and that's where they got their number. ......................................................................................... Agreed. The MIL SPEC or PIA SPEC probably specifies a minimum breaking strength of 725. If a suspension line is stronger than the MBS, it still passes the MIL SPEC inspection. Weaving and braiding mill managers often deliberately make suspension lines slightly over-strength to ensure that they pass final inspection. The only disadvantage to over-strength lines is "mystery bulk." The better factories also pull-test in-coming materials before sending them to the cutting table. If lines sent to Performance Designs consistently pass 825 pound tensile tests, then they can advertise their lines as 825. Quote Share this post Link to post Share on other sites
JerryBaumchen 1,318 #17 February 15, 2015 Hi Rob ( once again ), QuoteThe MIL SPEC or PIA SPEC . . . There is no req'ment in any of the many TSO standards as to any materials having to meet any MIL Spec or PIA Spec. In fact, the FAA is silent on this issue; as they should be. If a mfr wants to refer to MIL Spec/PIA Spec mat'ls in their Quality Program or their specifications ( thats drawings to most of us ), that is a choice the mfr makes. Some trivia about this mat'ls issue: The first company that I know of to use Cordura was the Altitude Shop in their Top Secret rig. At that time, Ted Strong wondered how they could use a non-MIL Spec mat'l. IMO Ted had been indoctrinated by the FAA in believing that one had to use MIL Spec mat'ls. Eventually, Cordura became a MIL Spec mat'l. Jerry Baumchen Quote Share this post Link to post Share on other sites
mcordell 2 #18 February 15, 2015 JerryBaumchenHi Rob ( once again ), QuoteThe MIL SPEC or PIA SPEC . . . There is no req'ment in any of the many TSO standards as to any materials having to meet any MIL Spec or PIA Spec. In fact, the FAA is silent on this issue; as they should be. If a mfr wants to refer to MIL Spec/PIA Spec mat'ls in their Quality Program or their specifications ( thats drawings to most of us ), that is a choice the mfr makes. Some trivia about this mat'ls issue: The first company that I know of to use Cordura was the Altitude Shop in their Top Secret rig. At that time, Ted Strong wondered how they could use a non-MIL Spec mat'l. IMO Ted had been indoctrinated by the FAA in believing that one had to use MIL Spec mat'ls. Eventually, Cordura became a MIL Spec mat'l. Jerry Baumchen BUT....in this case, the line is manufactured to mil-spec. There are no options for non mil-spec 725 spectre line because the global supplier manufactures it for government use. Because of that the line is source controlled and there are no other suppliers using spectre yarn from the inventor of spectre. It doesn't matter if you care that it is mil-spec or not when you order it...you get mil-spec regardless. Because of that, the mil-spec does in fact matter for the product if it is the reason they advertise it at 100 lbs under the actual tensile strength.www.facebook.com/FlintHillsRigging Quote Share this post Link to post Share on other sites
riggerrob 615 #19 February 15, 2015 Jerry, Thanks filling in the details. There are 2 extremes of quality control for parachute materials. At one extreme, only certified MIL SPEC/PIA SPEC materials are allowed into the factory. At the other extreme, the factory pull-tests, porosity-tests, all the materials as they arrive. Most factories use a mixture of both methods. One thing that is missing from home built parachute parts is the paper trail tracking all the materials from iron mine to final product. Quote Share this post Link to post Share on other sites
This Site Is For Sale
