Baller ski6jones Posted September 6, 2018 Baller Share Posted September 6, 2018 I measured my rope today with various numbers of twists and found a maximum change of just over 1 inch with 50 twists. I measured the 28 off loop with 0 to 50 twists incrementing by 10 (red) and 50 to 0 decrementing by 10 (green). The rope is about a year old. I tried to reduce measurement error by; Measuring under constant tension, about 45 pounds, Using constant tesnsion on the measuring tape by pulling it to the same length on a fixed object before making the measurement. Divisions on the tape were 0.002 m. It would appear that even with 50 twists, which seems like a lot, the change in length just exceeds 1 inch. The differences are from the initial measurement so there appears to be some hysterisis when unwinding the rope. Below 30 twists the difference is negligible. Link to comment Share on other sites More sharing options...
Baller Drago Posted September 6, 2018 Baller Share Posted September 6, 2018 What I thought Link to comment Share on other sites More sharing options...
Baller mwetskier Posted September 6, 2018 Baller Share Posted September 6, 2018 yeah, but slalom has been described as ' a game of inches '. plus which jamie beauchesne once said that the path needed to run 41 off is no wider than a garden hose. so theres that. Link to comment Share on other sites More sharing options...
Baller Zman Posted September 6, 2018 Baller Share Posted September 6, 2018 Any thoughts how springy or soft a rope might feel if excessively twisted? Link to comment Share on other sites More sharing options...
Baller Chef23 Posted September 6, 2018 Baller Share Posted September 6, 2018 @mwetskier if you are running 38 and shorter the inches make a difference. At 32 and longer not two inches doesn't make a difference. How much stiffer a twisted rope might feel to me is a bigger issue. I can see where a twisted rope would feel stiffer which is a bad thing for your hands and elbows. Link to comment Share on other sites More sharing options...
Baller mwetskier Posted September 6, 2018 Baller Share Posted September 6, 2018 @Chef23 -if i was running 38 and shorter i wouldn't care if the rope was shorter by an inch or two because the only time i'd be running 38 or shorter is in my dreams. Link to comment Share on other sites More sharing options...
Baller ski6jones Posted September 6, 2018 Author Baller Share Posted September 6, 2018 Below about 30 twists and the change is a few millimeters. When twisting the rope up to 50 it really started to resist being twisted. I don't think the rope would naturally twist that much, which I think also means the change in length is negligible for the number of twists the rope will take before the force required to add more twists becomes too great. I took out about 10 twists from my rope that were there from the last time I skied before starting to measure. On the stiffness of the rope I would think twists would make it feel less stiff. Another project for someone. Link to comment Share on other sites More sharing options...
Supporting Member Than_Bogan Posted September 6, 2018 Supporting Member Share Posted September 6, 2018 Cool data! I think you slightly buried the lede, though. The take-home is that any sane number of twists has negligible effect on rope length. Pretty fascinating that the rope just barely lengthens from the cycle of twisting and untwisting. (Right?) Link to comment Share on other sites More sharing options...
Baller ski6jones Posted September 6, 2018 Author Baller Share Posted September 6, 2018 Fair point @Than_Bogan, edited original post. And yes the rope lengthened a couple mm over the cycle of twist/untwist. Link to comment Share on other sites More sharing options...
Baller teammalibu Posted September 6, 2018 Baller Share Posted September 6, 2018 So I've been untwisting my rope all this time for nothing! Guess I'll keep doing it! @ski6jones thanks for the info! And great skiing this weekend congrats on your PB at quickset, the new windshield is on order! Link to comment Share on other sites More sharing options...
Baller BraceMaker Posted September 6, 2018 Baller Share Posted September 6, 2018 @Than_Bogan or all the loops shifted during tensioning and are just loosened. I think youd have to measure twist untwist. Ski it let it dry. Measure. Link to comment Share on other sites More sharing options...
Baller ConPexEr Posted September 7, 2018 Baller Share Posted September 7, 2018 @mwetskier you don't run 38? what do you run? Link to comment Share on other sites More sharing options...
Baller mwetskier Posted September 7, 2018 Baller Share Posted September 7, 2018 @ConPexEr -i mostly run from ex-wives and similar dangerous encounters. Link to comment Share on other sites More sharing options...
Baller JackQ Posted September 7, 2018 Baller Share Posted September 7, 2018 I don't think the difference of a twisted rope will make a difference in my skiing, but it still drives me mad and I will continue to unwind it. My questions, is when I fall and picked up the rope is always (or all most every time) twisted counterclockwise. Seem that it should be random. Link to comment Share on other sites More sharing options...
Baller dave2ball Posted September 7, 2018 Baller Share Posted September 7, 2018 A twisted rope will affect your skiing. Not only does the rope get shorter but the twisting does not allow the fibers to stretch as designed to. Link to comment Share on other sites More sharing options...
Baller BobF Posted September 7, 2018 Baller Share Posted September 7, 2018 @jackq I think it depends on the handle. Some handles tend to propeller one way or the other based on how they are strung. I've found that since I started using a head protector on my handle, no more rope twist. btw, I also can't help but unwind if needed while waiting for a start! Link to comment Share on other sites More sharing options...
Baller dave2ball Posted September 7, 2018 Baller Share Posted September 7, 2018 I really wouldn’t worry which way the rope twists. Link to comment Share on other sites More sharing options...
Baller thager Posted September 7, 2018 Baller Share Posted September 7, 2018 Unless you are south of the equator then they spin the other way! B) Link to comment Share on other sites More sharing options...
Baller dave2ball Posted September 7, 2018 Baller Share Posted September 7, 2018 @thager you are correct. Link to comment Share on other sites More sharing options...
Baller liquid d Posted September 8, 2018 Baller Share Posted September 8, 2018 It's just like an MLB batter stepping out of the box, adjusting the gloves, and getting back in the box. It keeps ya loose, and focusing---take every inch you can get! Link to comment Share on other sites More sharing options...
Baller 6balls Posted September 8, 2018 Baller Share Posted September 8, 2018 Totally subjective but a twisted rope feels "springy" to me. Don't like it. Link to comment Share on other sites More sharing options...
Baller DaveD Posted September 9, 2018 Baller Share Posted September 9, 2018 "Untwisting the rope" is code for taking a pee break on our lake. Link to comment Share on other sites More sharing options...
Baller Zman Posted September 10, 2018 Baller Share Posted September 10, 2018 @DaveD Or, need to get the soap out of my boots. Same code. Link to comment Share on other sites More sharing options...
Baller_ DW Posted September 10, 2018 Baller_ Share Posted September 10, 2018 I would expect a twisted rope to stretch and contract more than a non stretched rope. As it shortens, a load on it will cause it to stretch back closer to untwisted condition. A straight rope has less ability to stretch than a twisted one. Link to comment Share on other sites More sharing options...
Baller Triplett Posted September 10, 2018 Baller Share Posted September 10, 2018 I always thought of it as a stretch/springy-ness issue rather than length. Not entirely sure how we could quantify that. Link to comment Share on other sites More sharing options...
Baller_ DW Posted September 11, 2018 Baller_ Share Posted September 11, 2018 I was pondering the how to - perhaps attach one end to a fixed object, use a (fish) scale on the other and measure load v distance and overall length all relative to # or twists. Might make a great kids school project. Link to comment Share on other sites More sharing options...
Baller dave2ball Posted September 11, 2018 Baller Share Posted September 11, 2018 @DW the fish scale is a great thought. But when you ski a person can load the rope 600 lbs pls. If you have a fish scale for that and can get a measurable accurate number you are the man. Link to comment Share on other sites More sharing options...
Baller_ DW Posted September 14, 2018 Baller_ Share Posted September 14, 2018 So, I may need to reconsider my previous comment. I untwisted my main line and took a set and surprisingly the rope seemed to have a bit more stretch. Could be other factors but it sure did seem to be a bit more forgiving and stretchy. Just adds to my thought that it would make a great experiment. Of course like everything else in this sport, could be simply a mental thing. @dave2ball : the fish scale was more of a reference, I would think a 0-500 # scale would be wanted to get enough pull and accuracy. You could do it crudely with a few people of different mass and off the back of a tow hitch, simply measure distance v person leaning back at a prescribed angle, may not get enough accuracy that way. You may just get a subjective response using people leaning back in a fixed setting. Link to comment Share on other sites More sharing options...
Baller_ The_MS Posted September 14, 2018 Baller_ Share Posted September 14, 2018 We just flat out say we are warming up the lake when we pee. It is always good to add warm water to lake Link to comment Share on other sites More sharing options...
Baller BraceMaker Posted September 14, 2018 Baller Share Posted September 14, 2018 Get a cable and a pulley with a hook. 0-500 lb scale. Scale and cable connected to post with pulley and hook forming a V to the ski line. Now scale measures one half of the tension in the system. 0-1000 lbs. Multiply reading by 2. Link to comment Share on other sites More sharing options...
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