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tb182

silibands

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With my sorry 120 jumps I am not qualified to advise someone like you, but I gave up silibands after reading a letter in an old Parachutist issue.
A very experienced guy urged NOT to use silibands after he experienced a baglock. (Silibans didn’t break, where the regular rubber-bands would).

Don’t remember the issue, it was about 2-3 years old (you may have to do your own search).

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They will also break when you don't want them to, very bad for locking stows to break while the bag is being lifted off your back, exactly when there is the most stress on the bands.
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

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10 bands for 13$.. expensive vs rubber bands



Not to mention that I prefer rubber bands because thew will Break



agreed. I would say go ahead and use them but be aware of the risks....this from John Sherman of Jumpshack....

Rubber Bands Break For a Reason
It has become apparent to me that despite the problems in the past with out-of-sequence openings among other things, that people haven't learned that rubber bands break for a reason. The U.S. Government spent a lot of money developing a specification for parachute stow bands. In my 35 years in the sport I have never found an acceptable substitute. You might find a product which will work most of the time and which might seem to solve your breakage problem. But don't count on it working every time in every situation. If you think about it, you might ask why someone hasn't previously come up with a more durable product. It's such a simple matter, a stronger rubber band, and there are a lot of smart people who have come before us…. I remember the “Red” rubber band that was popular for a while in the 70's. They ended up melting and sticking to the grommets. I remember the Buna "N" "O" rings. They “spit” lines. I remember the Type 17 riser problem that was traced to a non-Mil. Spec Stow band. If you haven’t had a bag lock due to one of these breakable” stow bands – you probably will. I have witnessed three bag lock/cutaways that are directly attributable to “bands that would not break.” Consider this; Parachute "system" designers develop components based upon the characteristics of the stow band. This is a fact. I know, as that is what I do for a living, and have been doing it for over 30 years. I
strongly advise all parachutists to use only Mil Spec. Rubber Stow Bands. To use anything else can and will compromise your system. The really good aspect of all of this is that Mil. Spec. Rubber Bands cost considerably less than all of the new-fangled substitutes.

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Rubber Bands Break For a Reason



It doesn't matter if they're mil-spec or NASA approved or whatever, they break too easily to be used for locking stows, in my opinion.

John Sherman of Jump Shack is so unsure of the reliability of rubber bands that he felt it necessary to put a shit load of them on his reserve speed bag design. Why? Because he knows they break too easily, so he designed in multiple redundancy.

If they aren't to be trusted individually on your reserve bag for the locking stows, why should you trust them for your main? One locking stow breaking on a main D-bag can easily result in bag dump.

Bag locks still happen with mil-spec rubber bands, so I'll gladly take the failure mode trade off, thank you very much John Sherman.
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

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I just don't really understand the problem. I break locking stows all the time. My dbag has 4 locking stows. I assume (but don't know) that they break when they get pulled, which happens one at a time (I think). Instead of the lines sliding out, the band breaks. What's the difference? I can see why it might be a problem if they broke out of order... you'd end up with a bunch of line coming out all at once. But it's my understanding that stow bands just keep the opening in order and don't control the speed of the opening.

As I said, I break locking stows much more commonly than the non-locking stows. Never had a hard opening on my current canopy (~525 jumps or so). Can you just describe how a broken locking stow is likely to cause line dump? Would all of them have to break?

Dave

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I just don't really understand the problem. I break locking stows all the time. My dbag has 4 locking stows. I assume (but don't know) that they break when they get pulled, which happens one at a time (I think). Instead of the lines sliding out, the band breaks. What's the difference? I can see why it might be a problem if they broke out of order... you'd end up with a bunch of line coming out all at once. But it's my understanding that stow bands just keep the opening in order and don't control the speed of the opening.

As I said, I break locking stows much more commonly than the non-locking stows. Never had a hard opening on my current canopy (~525 jumps or so). Can you just describe how a broken locking stow is likely to cause line dump? Would all of them have to break?

Dave



Consider that the bands can face a lot of stress as the bag is accelerated off your back. All of the weight of the canopy is bearing against the mouth of the bag, held closed by the stows, and that force is increased because it is accelerated. Depending on how tight your canopy fits into the d-bag, the bands may already be stretched/stressed significantly before the additional stress occurs during deployment. I've seen many brand new bands start to crack the very first time they are used. If you're getting many jumps from your inner locking stows, then your canopy fits easily into the bag, and this is obviously much less of a problem. I only use tube stows for the inner 2 locking stows.

For a typical 4 locking stow bag, the outer 2 stows will not hold the canopy in the bag if the inner 2 stows are broken, sometimes it can't hold the canopy in even if just one of the inner stows is broken. Remember that if one of the inner stows breaks, the other will be subjected to greater stress - more likely to also break. All of this stress/potential to break can occur before line stretch.
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

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John Sherman of Jump Shack is so unsure of the reliability of rubber bands that he felt it necessary to put a shit load of them on his reserve speed bag design. Why? Because he knows they break too easily, so he designed in multiple redundancy.



not true. they are there for the orderly deployment of lines. just watch, all manufacturers will have something similar in the future. The point I was trying to make is rubber bands break and that is a good thing. I only have 2 locking stows and rarely have one break because I watch them and change before they break. This brings up another point, people more and more do not "know their gear" - shit, half of them don't even pack for themselves - no packer is going to change a rubber band unless it is already broken....

rm

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John Sherman of Jump Shack is so unsure of the reliability of rubber bands that he felt it necessary to put a shit load of them on his reserve speed bag design. Why? Because he knows they break too easily, so he designed in multiple redundancy.



not true. they are there for the orderly deployment of lines. just watch, all manufacturers will have something similar in the future. The point I was trying to make is rubber bands break and that is a good thing. I only have 2 locking stows and rarely have one break because I watch them and change before they break. This brings up another point, people more and more do not "know their gear" - shit half of them don't even pack for themselves - no packer is going to change a rubber band unless it is already broken....

rm



If you wanted to improve upon the orderly deployment of the lines compared to the std line pouch, it did not have to be done by making every stow a locking stow.

The speedbag could have been designed with fewer locking stows, even just 2 locking stows (like a std freebag) but it was not. I would be interested to know how many rubber band locking stows Mr. Sherman would have considered to be a minimum. I would bet that the answer is not 2.
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

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this discussion is on these new bands. I say use them if you want but know what the risks are....I'll continue to use (MIL spec) rubber bands based on the position of one of the few guys with 35 years experience in the business.

rm



And Bill Booth recommends tube stows for locking stows. We can do name dropping back and forth, I think it is more productive to talk about the logic behind the position that you advocate, and to understand there are risks either way.
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

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RWS only talks about and shows rubber bands in the owners manual I just down loaded. Anyway, it is up to the user. The "good" thing is baglock (due to a band which will not break) is a no brainer - cut away and dump the reserve - and quick since it is probably a high speed mal.

rm

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I just don't really understand the problem. I break locking stows all the time. My dbag has 4 locking stows. I assume (but don't know) that they break when they get pulled, which happens one at a time (I think). Instead of the lines sliding out, the band breaks. What's the difference? I can see why it might be a problem if they broke out of order... you'd end up with a bunch of line coming out all at once. But it's my understanding that stow bands just keep the opening in order and don't control the speed of the opening.

As I said, I break locking stows much more commonly than the non-locking stows. Never had a hard opening on my current canopy (~525 jumps or so). Can you just describe how a broken locking stow is likely to cause line dump? Would all of them have to break?

Dave



as the bag is being pull off your back the canopy wants to stay where it is. it is the locking stows which make the canopy go along for the ride. the locking stows see more stress at this time and if they are about to break (I say due to lack of maintenance) could at this time and allow the canopy out prematurely (I suppose not as likely with 4 locking stows). this is bag strip or line dump, and can result in a brutally hard opening. If the bag makes it to line stretch - what you say is true.

rm

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Does anyone know of a UK supplier of Parasport Silibands? Need size 2 for 825 microline.

I bought a pack (out of curiosity) that sat in my gear bag for awhile. However, have been using them for about past 75 jumps and they are great. Had always used Tube Stoes, but these are much better.
"Pain is the best instructor, but no one wants to attend his classes"

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