Loading ...
Sorry, an error occurred while loading the content.

[ksurf] Re: AW: AW: No Subject

Expand Messages
  • Carstens, Henning
    O.K i think a security is necessary for extrem kiting. But the most problem of breaking lines are the knots. There has to made some improvements or test for
    Message 1 of 3 , Dec 2, 1998
    • 0 Attachment
      O.K i think a security is necessary for extrem kiting.
      But the most problem of breaking lines are the knots.
      There has to made some improvements or test for the best,
      because to have thinner lines results in better upwind
      performance. Maybe 3/4 of w. is to extrem but something
      in the middle?.
      The use of 100 kg instead of 200 kg lines is a reduction
      of 500cm² (2lines) or 1000cm² (4lines) by a length of 30m.

      Only some facts to discuss.

      regards


      -----Ursprüngliche Nachricht-----
      Von: srosso@... [mailto:srosso@...]
      Gesendet am: Mittwoch, 2. Dezember 1998 19:45
      An: kitesurf@egroups.com
      Betreff: [ksurf] Re: AW: No Subject

      In a german kitemagazin was an article about some tests
      with different lines.
      result for traction you only need lines of 3/4 of the pilots weight, you
      do not need lines for 200 kg.

      What about when you go UP ??? then you need the total of the lines to
      support at LEAST your weight + there is the acceleration up.... so that
      might double your weight ! (if you accelerate up at 1 G)

      3/4 + 3/4 of your weight = 1.5 your weight
      Add the board harness wetsuit - water inside your wetsuit - and you have
      almost NO margin for error !!

      then consider when you are about to go for a jump and the wave lip
      crashes
      down on you and pushes you to the bottom of the sea - then you are
      talking
      about more than your weight ! maybe three times (you need a safety
      margin
      !! )- if you are an 80 kg flysurfer (with board and acessories) then you
      need 80 * 3 = 240 kg. Also the knots to connect weaken the lines - even
      when protected i heard that by 30% (ok, i am not sure)

      so 200 kg lines minus 30% can each hold 140 kg = total of 280 kg =
      compared
      to the 240 above
      sounds like 200 kg lines are about right !!

      I already had a line break in the sea - 500 meters from shore - it broke
      because the sand cut through the 4mm line connected at the boom... and
      luck
      would have it that i was flying with my soft foil - and the waves near
      shore where about 2 meters - i had a long swim and then the waves
      crashed
      me into the beach ... I dont recommend it... because after the swim I
      was
      too tired to go do more flysurfing!


      ------------------------------------------------------------------------
      Free Web-based e-mail groups -- http://www.eGroups.com
      ------------------------------------------------------------------------
      Free Web-based e-mail groups -- http://www.eGroups.com
    • Dave Culp
      ... Knotting any line, let alone kitelines, reduces its strength by 40-60%. It is quite possible to splice spectra kitelines; I ve done it for years. Splicing
      Message 2 of 3 , Dec 2, 1998
      • 0 Attachment
        >O.K i think a security is necessary for extrem kiting.
        >But the most problem of breaking lines are the knots.
        >There has to made some improvements or test for the best,
        >because to have thinner lines results in better upwind
        >performance. Maybe 3/4 of w. is to extrem but something
        >in the middle?.
        >The use of 100 kg instead of 200 kg lines is a reduction
        >of 500cm" (2lines) or 1000cm" (4lines) by a length of 30m.
        >
        >Only some facts to discuss.
        >
        >regards

        >Henning Carstens

        Knotting any line, let alone kitelines, reduces its strength by 40-60%.
        It is quite possible to splice spectra kitelines; I've done it for years.
        Splicing returns 90%+ of the line's original strength. It is difficult,
        however, to sleeve the lines after splicing (you have to pull the loop
        inside, *through* the lollow braid. This isn't possible with a sleeve,
        too). So, the finished loop needs a sewn-on sleeve, or reeving it round a
        small plastic or stainless thimble, for abrasion protection.

        As I said a month or so ago, you can learn to make a "no-knot" splice
        either by buying a specialized "no-knot" needle, with instructions, from
        any good kite shop, or you can go on the web and look for the
        instructions (the specialized needle is not needed--a long, thin piece of
        wire, bent double, will work). I believe I saw the instructions indexed
        (linked) somewhere on The Kiteflier's Site: http://wwwkfs.org/kites

        Alternatively, you can sew the line into a loop, and neither knot *nor*
        splice it. This is how parachutes are made. Double the line back on
        itself (inside a sleeve, as you do with knots) and run it several times
        through a zig-zag sewing machine. Amazingly, this will give you 80% (or
        so) of the original line's strength, if done even half-assed. Be sure to
        sew along a fairly long bit of line (couple of inches), and go back and
        forth at least twice.

        --
        Dave Culp Speedsailing dave@... http://www.dcss.org/speedsl
        Kite powered boats, high speed sailing, proas and more. Check it out!


        ------------------------------------------------------------------------
        Free Web-based e-mail groups -- http://www.eGroups.com
      • Mulder B.E. (Ben)
        I have been buggying for 7 years now and have never use lines stronger than 150 kgs and I am usually overpowered. I am 1.90 m (6 ft 5) and 90 kg heavy but even
        Message 3 of 3 , Dec 3, 1998
        • 0 Attachment
          I have been buggying for 7 years now and have never use lines stronger than
          150 kgs and I am usually overpowered. I am 1.90 m (6 ft 5) and 90 kg heavy
          but even with a crash or other emergencies I never broke a line unless the
          lines got cut by something (like barbed wire, kevlar lines of other kiter,
          seagull, boeing 747-400)
          I am quite new to kitesurfing as well but I tend to use stronger lines than
          with buggying because the strain on the lines are greater with a crash in
          the water than on land. On land you just get dragged along and so relieving
          high strain on the lines. You can imaging that there is higher strain on the
          lines when you go under water and the kite wants to go further. Once you are
          airborn there is little strain. ('to air is human!' says Cory)
          Furthermore I would like to react again on the of upwind capabilities
          comparing two- and four lined kites. I'm very sorry Pierce that I dared to
          comment on the master himself but... I am convinced that if you put up the
          same kites only one with two and the other with four lines of equal length,
          and note that I say equal length, the two lined kite flies more into the
          wind than the four lined. The remark that you can control a four lined kite
          better in that edge-area is a very sensible one. So maybe yes, you have a
          better upwind course with a four lined kite but because of better
          controlability but not performance. If I dive a two lined kite from high up
          to the edge of the windwindow that kite gets more speed than when you hold a
          four lined kite still in the same position (what most tend to do) and so you
          yourself get more speed. Don't get me wrong, I will probably be flying my
          four lined kites more, as I do with buggying, just because of controlability
          but I think that a two lined kite can perform better. I set my buggy
          speedrecord with a two lined framed kite.
          I have a set of 4 lines for my standard Quadrifoils of only 5 metres. Great
          performance in the windwindow but it overtakes you all the time, collapses,
          catches the wind again almost yanking you out the the buggy... really cool
          with high speed! ;-) But it can give you an advantage during a race. The
          longest set of 4 lines of me are 22 metres. The longest set of 2 lines of me
          are 45 metres.

          >>In a german kitemagazin was an article about some tests
          >>with different lines.
          >>result for traction you only need lines of 3/4 of the pilots
          weight, you
          >>do not need lines for 200 kg.

          >then consider when you are about to go for a jump and the wave lip
          crashes
          >down on you and pushes you to the bottom of the sea - then you are
          talking
          >about more than your weight ! maybe three times (you need a safety
          margin
          >!! )- if you are an 80 kg flysurfer (with board and acessories)
          then you
          >need 80 * 3 = 240 kg. Also the knots to connect weaken the lines -
          even
          >when protected i heard that by 30% (ok, i am not sure)

          >so 200 kg lines minus 30% can each hold 140 kg = total of 280 kg =
          compared
          >to the 240 above
          >sounds like 200 kg lines are about right !!


          ------------------------------------------------------------------------
          Free Web-based e-mail groups -- http://www.eGroups.com
        Your message has been successfully submitted and would be delivered to recipients shortly.