Creep0321 0 #1 February 20, 2012 I recently purchased a used rig, javelin oddesy, pilot 210 main, pdr 193.... just had the main and reserve inspected and the reserve really packed. I've been practicing packing the main, trying to learn how to pro pack (I was taught flat packing in the military ). Any way I noticed on my d bag there are multiple different sized rubber bands.. and one white tube stow, most of which need to be replaced. Any way to figure out what size rubber bands and or tube Stows I need? Thanks in advance.Jack of all trades. Military Free Fall Jumpmaster. USA Static-line Jumpmaster. Quote Share this post Link to post Share on other sites
jtfreefly 0 #2 February 20, 2012 I use big rubber bands on the first two locking stows and then small rubber bands for the rest. There a few great vids on YouTube about packing and proper line tension from performance designs. good luck. Quote Share this post Link to post Share on other sites
JohnRich 4 #3 February 20, 2012 QuoteAny way to figure out what size rubber bands and or tube Stows I need? The size that will hold your line groups securely. If in doubt, ask a packer, rigger, instructor or old fart. Quote Share this post Link to post Share on other sites
SStewart 13 #4 February 20, 2012 Have your rigger look at it, get rid of the tube stow. When I get a rig that has different stows of different lengths and elasticity I replace them all with new ones that provide proper tension to each stow. This is a question better asked in person by someone who can look at your bag once the canopy is in it. I am not a fan of tube stows, those things are supposed to break. An old master rigger once told me that every broken rubber band is a bag lock that never happened.Onward and Upward! Quote Share this post Link to post Share on other sites
sundevil777 93 #5 February 20, 2012 QuoteAn old master rigger once told me that every broken rubber band is a bag lock that never happened.Quote What a load of bull. Rubber bands break because they aren't strong enough. Haven't we all installed a new band, only to have it start splitting just from the stress of pulling the larks head tight while installing it? Your master rigger friend would have been more correct to say that every broken middle locking stow rubber band was a potential bag dump that came close to happening, only prevented by the other middle locking stow that had more stress on it due to its neighbor breaking. Of course bands also break at at the time that the line group is pulled out, but the bands are also under a lot of stress when the bag is lifted off your back (accelerated), which happens to be the worst time to suffer a broken rubber band. Even for d-bags with 4 locking stows, break the middle two and the canopy can likely ejected. Bag locks have occurred even with rubber bands, and bag dump can happen with tube stows. I understand the theory behind limited strength rubber bands. I do not understand how so many do not acknowledge the other side of that tradeoff.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SStewart 13 #6 February 20, 2012 You are over thinking this dude, my post was tongue in cheek but apparently went over your head. Rubber bands are supposed to break.Onward and Upward! Quote Share this post Link to post Share on other sites sundevil777 93 #7 February 20, 2012 QuoteYou are over thinking this dude, my post was tongue in cheek but apparently went over your head. Rubber bands are supposed to break. OK, my mistake, but how am I or a newbie to tell when your tongue is in your cheek? You seemed pretty serious. Yes, rubber bands are supposed to break. It can be very dangerous for them to break at the wrong time, which is exactly when they are stressed the most.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SStewart 13 #8 February 20, 2012 Read the entire post, I am pretty sure I told the newbie to have a rigger check it, proper tension, etc. Not a fan of tube stows, and I have have had a bag lock that would not have happened with a rubber band. I have some pics maybe I can find to show you what I mean.Onward and Upward! Quote Share this post Link to post Share on other sites cube 0 #9 February 20, 2012 QuoteNot a fan of tube stows, and I have have had a bag lock that might not have happened with a rubber band. fyp. I've seen bag locks with standard rubber bands too. I've used tubes for 500 jumps now no problem. I take some care in stowing the lines though. [edit] not saying it wouldn't somewhat increase the risk of a bag lock though.[/edit] Quote Share this post Link to post Share on other sites SStewart 13 #10 February 20, 2012 I have also used tube stows for hundreds of jumps with no problems. After I had a problem I quit using them. They are much stronger than rubber bands and therefore much harder to break if something gets hung up. I would prefer to have it break.Onward and Upward! Quote Share this post Link to post Share on other sites skydiverek 54 #11 February 20, 2012 QuoteYes, rubber bands are supposed to break. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=Rubberbands&SortBy=DATE_D Quote Share this post Link to post Share on other sites skydiverek 54 #12 February 20, 2012 QuoteAn old master rigger once told me that every broken rubber band is a bag lock that never happened. Close to the topic: http://www.youtube.com/watch?v=4Nsca5add8g Quote Share this post Link to post Share on other sites sundevil777 93 #13 February 20, 2012 QuoteQuoteYes, rubber bands are supposed to break. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=Rubberbands&SortBy=DATE_D I think it is worth noting that when Mr. Sherman of the Jump Shack (Racer) designed his speed bag, he did not trust just a couple rubber bands to hold the d-bag closed. He applied a lot of rubber bands, and the flap that is closed by them doesn't get the inertial load because it is located differently than the typical d-bag. Regarding double stowing of lines not causing bag locks (the PD video), I would agree but putting even more stress on the band makes it more likely to break when you don't want it to. How many keep using a rubber locking stow even though it has some visible cut or tear? That is quite common in my experience, and is an instance of bag dump waiting to happen. It is a very reasonable thing to not want the middle locking stows to break. They get a lot of stress applied to them.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #14 February 20, 2012 Quote They are much stronger than rubber bands and therefore much harder to break if something gets hung up. I would prefer to have it break. This is also a myth that has been disproven time and time again, but somehow people seem to keep spreading it. Try this at home. Actually try this, you'll amaze yourself. Take a spring scale, you can buy them for fishing, they're used for fabric pull strength tests. Take a BRAND NEW tube stoe and hook up the spring scale, pull until it breaks. Record the breakforce required. Now take a BRAND NEW rubber band and hook up the spring scale, pull it until it breaks. Record the breakforce required. I'll tell you how my numbers looked: Tube Stoe fails at between 30-40 lbs at the overlapping connection point. I could not get a reading on the rubber band, because my spring scale only goes up to 55lbs and the rubber band still would not break. Tube Stoes are NOT stronger than rubber bands and DO break at lower force when compared new. Here's where the difference lies. Tube Stoes wear less than traditional rubber bands because they are round, roll, and don't have corners. Since they wear less, they hold their normal required breakforce a lot longer. Since rubber bands wear a lot faster, their required breakforce drops off very quickly to below what a tube stoe would require with the same amount of use. If you put on a NEW rubber band, they are much stronger than tube stoes and therefore much harder to break if something gets hung up. Try this simple and inexpensive experiment for yourself instead of retelling false old wives tales.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites sundevil777 93 #15 February 20, 2012 QuoteTube Stoe fails at between 30-40 lbs at the overlapping connection point. Did you check them with the connection point in the base of the larks head? I don't even glue the tube stows I make, so the tension definitely doesn't affect them there. It always seemed obvious to install them that way. Anyway, 40 lbs of strength is plenty, but bands quickly get weak with use. They get abraded, spit, torn, sometimes just from installing them (setting the larks head tight).People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #16 February 20, 2012 I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites Deyan 31 #17 February 20, 2012 Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle "My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen Quote Share this post Link to post Share on other sites Rstanley0312 0 #18 February 20, 2012 Quote I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. Tube Stows are the devil! You will get a bag lock and you may die with them........ Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it. Muff Brother #4382 Dudeist Skydiver #000 www.fundraiseadventure.com Quote Share this post Link to post Share on other sites sundevil777 93 #19 February 20, 2012 QuoteI've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. I make my tube stows with no glue, just put the connection in the base of the larks head. The stows will pull apart really easy before they're installed, but don't seem to see much stress at all after installed. I've never tried to put near 40 lbs on them, perhaps they would come apart, but I don't think so.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #20 February 20, 2012 Quote Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle I just happen to have a few bags lying around that came from PD. We bought some new canopies last year and PD usually sends you a bunch with them. Just did a test yet again after reading your post. Still made it to 55lbs with no break or damage to the rubber band. Tested the rubber band was both in a larks head knot configuration and not knotted, no breaky. Not sure what supplier you've gotten rubber bands from, but I've never once seen a brand new rubber band break in 40lbs. I've seen plenty of worn/used ones break low, but never a brand new one. And given you've also got the same test result I have from multiple bands, I think it's safe to assume there are plenty of rubber bands out there circulating in use that will not break when new with any reasonable force.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites Hellis 0 #21 February 20, 2012 Maybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. Quote Share this post Link to post Share on other sites Squeak 17 #22 February 21, 2012 QuoteMaybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. When you "larks head" you reduce the breaking strain, so it will not be 2X the the single length.You are not now, nor will you ever be, good enough to not die in this sport (Sparky) My Life ROCKS! How's yours doing? Quote Share this post Link to post Share on other sites Hellis 0 #23 February 21, 2012 True, but I suppose the tests Simon made was not with a larkshead knot. As I understand it he used the band as it's original shape, a loop. Quote Share this post Link to post Share on other sites JohnSherman 1 #24 February 21, 2012 Not only is the breaking strength of a rubber ban significant but the elasticity is also important. I an linking to an article I wrote before we designed the "SPEED" bag when we first learned about "Balancing the mass of the stow". This will perhaps provide more insight as to the importance of Mil Spec stow bands. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=NEWSTOW&SortBy=DATE_D Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0 Go To Topic Listing
SStewart 13 #6 February 20, 2012 You are over thinking this dude, my post was tongue in cheek but apparently went over your head. Rubber bands are supposed to break.Onward and Upward! Quote Share this post Link to post Share on other sites
sundevil777 93 #7 February 20, 2012 QuoteYou are over thinking this dude, my post was tongue in cheek but apparently went over your head. Rubber bands are supposed to break. OK, my mistake, but how am I or a newbie to tell when your tongue is in your cheek? You seemed pretty serious. Yes, rubber bands are supposed to break. It can be very dangerous for them to break at the wrong time, which is exactly when they are stressed the most.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
SStewart 13 #8 February 20, 2012 Read the entire post, I am pretty sure I told the newbie to have a rigger check it, proper tension, etc. Not a fan of tube stows, and I have have had a bag lock that would not have happened with a rubber band. I have some pics maybe I can find to show you what I mean.Onward and Upward! Quote Share this post Link to post Share on other sites
cube 0 #9 February 20, 2012 QuoteNot a fan of tube stows, and I have have had a bag lock that might not have happened with a rubber band. fyp. I've seen bag locks with standard rubber bands too. I've used tubes for 500 jumps now no problem. I take some care in stowing the lines though. [edit] not saying it wouldn't somewhat increase the risk of a bag lock though.[/edit] Quote Share this post Link to post Share on other sites
SStewart 13 #10 February 20, 2012 I have also used tube stows for hundreds of jumps with no problems. After I had a problem I quit using them. They are much stronger than rubber bands and therefore much harder to break if something gets hung up. I would prefer to have it break.Onward and Upward! Quote Share this post Link to post Share on other sites
skydiverek 54 #11 February 20, 2012 QuoteYes, rubber bands are supposed to break. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=Rubberbands&SortBy=DATE_D Quote Share this post Link to post Share on other sites
skydiverek 54 #12 February 20, 2012 QuoteAn old master rigger once told me that every broken rubber band is a bag lock that never happened. Close to the topic: http://www.youtube.com/watch?v=4Nsca5add8g Quote Share this post Link to post Share on other sites
sundevil777 93 #13 February 20, 2012 QuoteQuoteYes, rubber bands are supposed to break. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=Rubberbands&SortBy=DATE_D I think it is worth noting that when Mr. Sherman of the Jump Shack (Racer) designed his speed bag, he did not trust just a couple rubber bands to hold the d-bag closed. He applied a lot of rubber bands, and the flap that is closed by them doesn't get the inertial load because it is located differently than the typical d-bag. Regarding double stowing of lines not causing bag locks (the PD video), I would agree but putting even more stress on the band makes it more likely to break when you don't want it to. How many keep using a rubber locking stow even though it has some visible cut or tear? That is quite common in my experience, and is an instance of bag dump waiting to happen. It is a very reasonable thing to not want the middle locking stows to break. They get a lot of stress applied to them.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #14 February 20, 2012 Quote They are much stronger than rubber bands and therefore much harder to break if something gets hung up. I would prefer to have it break. This is also a myth that has been disproven time and time again, but somehow people seem to keep spreading it. Try this at home. Actually try this, you'll amaze yourself. Take a spring scale, you can buy them for fishing, they're used for fabric pull strength tests. Take a BRAND NEW tube stoe and hook up the spring scale, pull until it breaks. Record the breakforce required. Now take a BRAND NEW rubber band and hook up the spring scale, pull it until it breaks. Record the breakforce required. I'll tell you how my numbers looked: Tube Stoe fails at between 30-40 lbs at the overlapping connection point. I could not get a reading on the rubber band, because my spring scale only goes up to 55lbs and the rubber band still would not break. Tube Stoes are NOT stronger than rubber bands and DO break at lower force when compared new. Here's where the difference lies. Tube Stoes wear less than traditional rubber bands because they are round, roll, and don't have corners. Since they wear less, they hold their normal required breakforce a lot longer. Since rubber bands wear a lot faster, their required breakforce drops off very quickly to below what a tube stoe would require with the same amount of use. If you put on a NEW rubber band, they are much stronger than tube stoes and therefore much harder to break if something gets hung up. Try this simple and inexpensive experiment for yourself instead of retelling false old wives tales.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites sundevil777 93 #15 February 20, 2012 QuoteTube Stoe fails at between 30-40 lbs at the overlapping connection point. Did you check them with the connection point in the base of the larks head? I don't even glue the tube stows I make, so the tension definitely doesn't affect them there. It always seemed obvious to install them that way. Anyway, 40 lbs of strength is plenty, but bands quickly get weak with use. They get abraded, spit, torn, sometimes just from installing them (setting the larks head tight).People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #16 February 20, 2012 I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites Deyan 31 #17 February 20, 2012 Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle "My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen Quote Share this post Link to post Share on other sites Rstanley0312 0 #18 February 20, 2012 Quote I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. Tube Stows are the devil! You will get a bag lock and you may die with them........ Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it. Muff Brother #4382 Dudeist Skydiver #000 www.fundraiseadventure.com Quote Share this post Link to post Share on other sites sundevil777 93 #19 February 20, 2012 QuoteI've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. I make my tube stows with no glue, just put the connection in the base of the larks head. The stows will pull apart really easy before they're installed, but don't seem to see much stress at all after installed. I've never tried to put near 40 lbs on them, perhaps they would come apart, but I don't think so.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites SimonBones 1 #20 February 20, 2012 Quote Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle I just happen to have a few bags lying around that came from PD. We bought some new canopies last year and PD usually sends you a bunch with them. Just did a test yet again after reading your post. Still made it to 55lbs with no break or damage to the rubber band. Tested the rubber band was both in a larks head knot configuration and not knotted, no breaky. Not sure what supplier you've gotten rubber bands from, but I've never once seen a brand new rubber band break in 40lbs. I've seen plenty of worn/used ones break low, but never a brand new one. And given you've also got the same test result I have from multiple bands, I think it's safe to assume there are plenty of rubber bands out there circulating in use that will not break when new with any reasonable force.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites Hellis 0 #21 February 20, 2012 Maybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. Quote Share this post Link to post Share on other sites Squeak 17 #22 February 21, 2012 QuoteMaybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. When you "larks head" you reduce the breaking strain, so it will not be 2X the the single length.You are not now, nor will you ever be, good enough to not die in this sport (Sparky) My Life ROCKS! How's yours doing? Quote Share this post Link to post Share on other sites Hellis 0 #23 February 21, 2012 True, but I suppose the tests Simon made was not with a larkshead knot. As I understand it he used the band as it's original shape, a loop. Quote Share this post Link to post Share on other sites JohnSherman 1 #24 February 21, 2012 Not only is the breaking strength of a rubber ban significant but the elasticity is also important. I an linking to an article I wrote before we designed the "SPEED" bag when we first learned about "Balancing the mass of the stow". This will perhaps provide more insight as to the importance of Mil Spec stow bands. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=NEWSTOW&SortBy=DATE_D Quote Share this post Link to post Share on other sites Join the conversation You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Reply to this topic... × Pasted as rich text. Paste as plain text instead Only 75 emoji are allowed. × Your link has been automatically embedded. Display as a link instead × Your previous content has been restored. Clear editor × You cannot paste images directly. Upload or insert images from URL. Insert image from URL × Desktop Tablet Phone Submit Reply 0
SimonBones 1 #14 February 20, 2012 Quote They are much stronger than rubber bands and therefore much harder to break if something gets hung up. I would prefer to have it break. This is also a myth that has been disproven time and time again, but somehow people seem to keep spreading it. Try this at home. Actually try this, you'll amaze yourself. Take a spring scale, you can buy them for fishing, they're used for fabric pull strength tests. Take a BRAND NEW tube stoe and hook up the spring scale, pull until it breaks. Record the breakforce required. Now take a BRAND NEW rubber band and hook up the spring scale, pull it until it breaks. Record the breakforce required. I'll tell you how my numbers looked: Tube Stoe fails at between 30-40 lbs at the overlapping connection point. I could not get a reading on the rubber band, because my spring scale only goes up to 55lbs and the rubber band still would not break. Tube Stoes are NOT stronger than rubber bands and DO break at lower force when compared new. Here's where the difference lies. Tube Stoes wear less than traditional rubber bands because they are round, roll, and don't have corners. Since they wear less, they hold their normal required breakforce a lot longer. Since rubber bands wear a lot faster, their required breakforce drops off very quickly to below what a tube stoe would require with the same amount of use. If you put on a NEW rubber band, they are much stronger than tube stoes and therefore much harder to break if something gets hung up. Try this simple and inexpensive experiment for yourself instead of retelling false old wives tales.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
sundevil777 93 #15 February 20, 2012 QuoteTube Stoe fails at between 30-40 lbs at the overlapping connection point. Did you check them with the connection point in the base of the larks head? I don't even glue the tube stows I make, so the tension definitely doesn't affect them there. It always seemed obvious to install them that way. Anyway, 40 lbs of strength is plenty, but bands quickly get weak with use. They get abraded, spit, torn, sometimes just from installing them (setting the larks head tight).People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
SimonBones 1 #16 February 20, 2012 I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
Deyan 31 #17 February 20, 2012 Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle "My belief is that once the doctor whacks you on the butt, all guarantees are off" Jerry Baumchen Quote Share this post Link to post Share on other sites
Rstanley0312 0 #18 February 20, 2012 Quote I've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. Tube Stows are the devil! You will get a bag lock and you may die with them........ Life is all about ass....either you're kicking it, kissing it, working it off, or trying to get a piece of it. Muff Brother #4382 Dudeist Skydiver #000 www.fundraiseadventure.com Quote Share this post Link to post Share on other sites
sundevil777 93 #19 February 20, 2012 QuoteI've done this both ways. When the connection point is parallel to the pulling direction I've had breaks as low as 25lbs, but generally closer to 30lbs. When the connection point was perpendicular to the pull direction, I had a break once as high as 45lbs, but most were generally closer to 40lbs. Every time a tube stoe failed it always failed at the connection point. So, you can change what your breakforce will be on your bag by how you hook up your tube stoe. If you hook it up the recommended way, with the larks head leaving the connection point at the bottom and perpendicular to pull direction, your required breakforce will be in the higher end of the band. If you hook them up to your bag the not-recommended way with the connection going around your lines, you will have a lower breakforce. I make my tube stows with no glue, just put the connection in the base of the larks head. The stows will pull apart really easy before they're installed, but don't seem to see much stress at all after installed. I've never tried to put near 40 lbs on them, perhaps they would come apart, but I don't think so.People are sick and tired of being told that ordinary and decent people are fed up in this country with being sick and tired. I’m certainly not, and I’m sick and tired of being told that I am Quote Share this post Link to post Share on other sites
SimonBones 1 #20 February 20, 2012 Quote Which rubber bands you have used for the test? Mil Spec. will break at no more than 40 lbs every time ,but once I've tested rubber bands that stayed in one piece even after my fish scale ( 55 lbs) made a full circle I just happen to have a few bags lying around that came from PD. We bought some new canopies last year and PD usually sends you a bunch with them. Just did a test yet again after reading your post. Still made it to 55lbs with no break or damage to the rubber band. Tested the rubber band was both in a larks head knot configuration and not knotted, no breaky. Not sure what supplier you've gotten rubber bands from, but I've never once seen a brand new rubber band break in 40lbs. I've seen plenty of worn/used ones break low, but never a brand new one. And given you've also got the same test result I have from multiple bands, I think it's safe to assume there are plenty of rubber bands out there circulating in use that will not break when new with any reasonable force.108 way head down world record!!! http://www.simonbones.com Hit me up on Facebook Quote Share this post Link to post Share on other sites
Hellis 0 #21 February 20, 2012 Maybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. Quote Share this post Link to post Share on other sites
Squeak 17 #22 February 21, 2012 QuoteMaybe it has a 40 lbs breakforce in the material, but as the rubber band is in a loop you will need 80 lbs to break it? So if you stretch one side of the rubber band it will break at 40 lbs, but when you pull on it the load will distribute on both sides resulting in 1/2 of the force. Just a thought. EDIT: Riggers might chime in here nut isn't that the way the MIL spec is rated? If you look at webbing, for example typ 4, rated at 1000 lbs, thats in one way. Not when you make a loop of it. When you "larks head" you reduce the breaking strain, so it will not be 2X the the single length.You are not now, nor will you ever be, good enough to not die in this sport (Sparky) My Life ROCKS! How's yours doing? Quote Share this post Link to post Share on other sites
Hellis 0 #23 February 21, 2012 True, but I suppose the tests Simon made was not with a larkshead knot. As I understand it he used the band as it's original shape, a loop. Quote Share this post Link to post Share on other sites
JohnSherman 1 #24 February 21, 2012 Not only is the breaking strength of a rubber ban significant but the elasticity is also important. I an linking to an article I wrote before we designed the "SPEED" bag when we first learned about "Balancing the mass of the stow". This will perhaps provide more insight as to the importance of Mil Spec stow bands. http://www.jumpshack.com/default.asp?CategoryID=TECH&PageID=NEWSTOW&SortBy=DATE_D Quote Share this post Link to post Share on other sites
