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ernokaikkonen

Racer speedbag

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I found that Mil-Spec rubber bands last 2 years or more when packed into pilot emergency parachutes in the hot, dry, dusty Southern California desert.

Shelf life of (open packages) rubber bands is closer to 4 years.

The vast majority of round reserves use 2 or 3 rubber bands as locking stows on their diapers and the rest of the lines are stowed in rubber bands on the diaper (modern) or in the pack tray (old school).

The only round canopies that do not use rubber bands are some older (before the Mil-Spec was written) military designs, either reallllllllllllly old or for ejection seats. Some ejection seats don't use rubber bands, because rubber bands are not reliable above 250 or 300 knots ... way outside the skydiving envelope.

In conclusion, rubber bands pre-date (cloth covered) Safety Stows. They worked great for decades - and still work great in modern round reserves/PEP - so I do not understand why Erno is making such a big fuss about Speed Bags closed with Mil-Spec rubber bands???????

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I do not understand why Erno is making such a big fuss about Speed Bags closed with Mil-Spec rubber bands???????



I think a good reason to question the speedbag design is described in an earlier post (post #18) of this thread:

http://www.dropzone.com/cgi-bin/forum/gforum.cgi?post=2096406#2096406

I think something could be done to help prevent the knot from being able to come through the grommet and effectively locking it, perhaps a cone shaped cover of some sort - something could be done. I think it is worthy of investigation, as it does seem to be a valid failure mode that could be fixed.
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 think something could be done to help prevent the knot from being able to come through the grommet and effectively locking it, perhaps a cone shaped cover of some sort - something could be done. I think it is worthy of investigation, as it does seem to be a valid failure mode that could be fixed.



>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Ha!
Ha!
Another person re-inventing the wheel.
There is a good reason we discarded brass cones 30 years ago.
A worn brass cone is worse than no cone because a grommet could hang-up in the groove that it wore in the side of the cone.

The simple answer is to make soft grommets large enough that the knot cannot jam in it.

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Keener Rubber Company of Alliance OH makes Mil. Spec. Rubber Bands. They are available from Jump Shack and other manufacturers and dealers.
Here are Excerpted Specifications for Mil-PRF-1832E Type I and Type II Parachute bands
Type I Mil-PRF-1832E 2 x 1/2 x .032 (MIL-R-1832 Rev D was .040)
Type II Mil-PRF-1832E 2 x 3/8 x .062
Table I. Physical Requirements

Property Type I Type II
Permanent set, percent (maximum)
(after 500 +/- 50 percent
elongation for 10 minutes) 20 15

Breaking force, pounds (minimum)
Initial 45 50
After aging not less than 75% of initial figure

Ultimate elongation, percent (minimum)
Initial 700 650
After aging not less than 75% of initial figure

Weight (minimum), bands/pound 390 300

Flat Length: +/- 1/8 inch
Width: Type I +/- 1/16 inch
Wall Thickness: +5 percent, -0 percent

Table III. Test Methods

Characteristic Req. ASTM Requirements Number Results
Ref test Applicable to deter- to nearest
Method minations
Unit Lot per unit
Permanent set 3.3 D412 yes one 1 percent
Breaking force
Lbs./min:
Initial 3.3 D412 yes one 1 pound
After Aging 3.3 D573 yes one 1 pound
Ultimate elongation
Percent
(minimum)
Initial 3.3 D412 yes one 1 percent
After Aging 3.3 D573 yes one 1 percent
Weight 3.3 yes one 0.1 ounce


The old style bungee stow bag with the pouch IS broken, and DOES need fixing. The one case of a canopy being left behind in a container was the result of line dump out of a bag with a POUCH, and only two locking stows. The Speed Bag has 5 to 8 locking stows depending on the size of the canopy.

The one case (that I know of) of a freebag that bag locked involved a bag with a BUNGEE STOW that would not break. If there had been rubber bands on that bag - at least one (probably both) would have broken, allowing canopy out of the bag. There is no more potential for bag lock on the Speed Bag than on the old style bungee stow bag that uses a pouch. Some times a canopy will be extracted out of one side of the bag prior to the other side because the canopy will go the path of least resistance. I personally have thousands of jumps on a main Speed Bag and at least a dozen intentional cutaways using a reserve Speed Bag, with no hesitations or locks whatsover.

Without a doubt there has been more field testing of the Speedbag than the old style bungee stow freebag, as we have been using the design on main bags for nearly seven years and (tens of) thousands of jumps.

For those of you who aren't familiar with pilot rigs, round reserves and parachuting history in general, the sport has been using rubber bands on reserves for 60 or more years, very successfully and reliably. Ask some "old" rigger how a diaper works - ask to see a demonstration of one. The mechanics of the Speed Bag will become more clear to you.

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I forgot to mention the other deficiency of the old style bungee stow/pouch freebag - the destruction of reserve canopies in the event of line strip. There've been several instances where lines tore from reserve canopies, or canopies blew up as a result of line strip. It's not that the canopies were not built strong enough - it's that the deployment system did not meter the lines out in a controlled manner, and sufficiently soften the opening. There has been more than one fatality as a result.

Heavy jumpers using small reserves are most susceptible, but jumpers at high altitude DZ's and freeflyers and other "high speed" jumpers are at risk as well.

Recent student harness failures are the direct result of line strip openings.

People don't realize that the manufacturers of reserve canopies don't do their high speed heavy drops using the old style freebag w/bungee stow & pouch. The canopies wouldn't pass the test (they'd probably blow up or blow thier lines off). All the major manufacturers use "special" bags wherein every stow is a locking stow so that the canopies will take the vicious openings encountered when you static line a 97 sq ft reserve with a 300 pound load at 180 mph! Then those canopies go out into the field where they are assembled into bags that practically guarantee a line dump.

Jump Shack was the first company to seriously address the problem. Other companies are beginning to follow suit. The sooner they all do, the better off you'll all be.

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Without a doubt there has been more field testing of the Speedbag than the old style bungee stow freebag, as we have been using the design on main bags for nearly seven years and (tens of) thousands of jumps.

You might want to check your facts since your own web site says that it has been less than three years HERE.

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Without a doubt there has been more field testing of the Speedbag than the old style bungee stow freebag, as we have been using the design on main bags for nearly seven years and (tens of) thousands of jumps.

You might want to check your facts since your own web site says that it has been less than three years HERE.



The date of us starting to test it, and the date of us releasing it to the Skydiving public are two different things......... :)
Pete Draper,

Just because my life plan is written on the back of a Hooter's Napkin, it's still a life plan.... right?

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I think something could be done to help prevent the knot from being able to come through the grommet and effectively locking it, perhaps a cone shaped cover of some sort - something could be done. I think it is worthy of investigation, as it does seem to be a valid failure mode that could be fixed.



>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Ha!
Ha!
Another person re-inventing the wheel.
There is a good reason we discarded brass cones 30 years ago.
A worn brass cone is worse than no cone because a grommet could hang-up in the groove that it wore in the side of the cone.

The simple answer is to make soft grommets large enough that the knot cannot jam in it.



I never suggested a brass anything.
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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Why do you still offer the old style bungee stow/pouch freebag if it results in fatalities? Is it just because some will not yet accept your speedbag design.

If you have such an important safety advantage on your competition that is being rejected by many, why not educate them in your ads? You market some of the other more unique aspects of your rigs as being a safer design. Jumpers love safety advantages, you're the only ones with it.
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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The date of us starting to test it, and the date of us releasing it to the Skydiving public are two different things.........

Four years difference? I don't think so. But then this has always been a problem with Jump Shack, they make a good product then loose credibility with exaggerations.

And as far as "testing it" you might want to check with the FAA as they do not show any record of a change submission to allow the speedbag as part of the TSO.

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Why do you still offer the old style bungee stow/pouch freebag if it results in fatalities? Is it just because some will not yet accept your speedbag design.

If you have such an important safety advantage on your competition that is being rejected by many, why not educate them in your ads? You market some of the other more unique aspects of your rigs as being a safer design. Jumpers love safety advantages, you're the only ones with it.



The guy that started this post is a perfect example of why some people want the old style. There alot of riggers out there who are too busy preaching thier opinion that they don't have the time to listen. If there is proof that they are wrong, then the fault lies in the proof, not thier opinion.

You can't teach a student who refuses to learn.

Finally, spaeking as one who markets a product, I've learn't that you can't sell the steak, you've gotta sell the sizzle.

When you see an ad for a drug, do they go into the test trials and years of development? Remember the "milk ... It does a body good" ad? It didn't talk about the specifics of what calcium and Vitimin "D" does.
And I've yet to see an egg ad that talks about the advantages of Omega 3s, 6s and 9s. (although the "Get crackin'" sloagan was quite effective)
Nancy's post was very interesting but if I saw it on an ad, I'd flip the page.

Marketing is never about fact. Marketing is about puffery.

After all, how can Coke and Pepsi both have the best taste and yet not taste the same.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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Nancy,

I agree that bands are indeed more suitable for reserves than the pouch/freestow pocket.

My concern is that I have seen at least three rigs come to me for a repack where the speedbag had to be peeled open after no amount of pulling on the rig and the bridle of the speedbag would allow it to open. IMHO it was where the knot of the band had pulled through that was locking this.

As I have stated in another thread previously one of the first Speedbag's I got in for a repack was what brought this to my attention as it was impossible to clear the canopy from the bag without peeling back the top flap as it was locked by the bands.

I did a number of packs and pulls on that rig before I was happy that with careful monitoring of the bands NOT being allowed to be pulled through that it would work as intended before I signed the rig out to its owner for use.

I personally know of at least one rigger who has taken their speedbag out of their Racers and reverted to the old style of bag. Why? Because whether there is or is not a Genuine Issue there is certainly a Perceived Issue.

I for one continue to pack Speedbags paying particular attention to the stows and ensuring that they do not get pulled through the hole and have since had no issues with them at all.

Not being a designer of rigs with Jump Shacks combined experience I could not suggest what would be the best solution. One thought that I had was to turn the attachment point for the stowband through ninety degrees. This elimante the potential for a stowband locking almost to nil. This is due to the shape of the knot created by the band on the stow point, by turning it through ninety degrees and ensureing the correct direction is followed when feeding the band through itself there is no edge for the hole to catch on.

I will try and get a couple of pictures up tonight to clarify.
I like my canopy...


...it lets me down.

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People don't realize that the manufacturers of reserve canopies don't do their high speed heavy drops using the old style freebag w/bungee stow & pouch. The canopies wouldn't pass the test (they'd probably blow up or blow thier lines off). All the major manufacturers use "special" bags wherein every stow is a locking stow so that the canopies will take the vicious openings encountered when you static line a 97 sq ft reserve with a 300 pound load at 180 mph! Then those canopies go out into the field where they are assembled into bags that practically guarantee a line dump.



How do these manufactures deal with the requirments of AS8015-B sections 2.1.2, 4.3.4, 4.3.4.2, and 5.1?

Sparky
My idea of a fair fight is clubbing baby seals

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People don't realize that the manufacturers of reserve canopies don't do their high speed heavy drops using the old style freebag w/bungee stow & pouch. The canopies wouldn't pass the test (they'd probably blow up or blow thier lines off). All the major manufacturers use "special" bags wherein every stow is a locking stow so that the canopies will take the vicious openings encountered when you static line a 97 sq ft reserve with a 300 pound load at 180 mph! Then those canopies go out into the field where they are assembled into bags that practically guarantee a line dump.



That is quite a claim. Any other manufactures out there care to comment?
_________________________________________

Nullius in Verba

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I don't believe in line dump, (otherwise freestowed lines would always "dump", but they don't) although I do believe that a canopy that starts inflating before it hits line stretch is a serious issue. That being said, the line stow pouch and primary stow on a freebag or tail pocket (base) are exceedingly reliable. The speedbag solves a problem that simply does not exist.

When I received a reserve speedbag as a replacement for a lost freebag, I thought it was a really poor, 30 year old design. Reading about locked bags on this thread confirms what I thought. I had to sign a waiver to get a standard bag.

Jump Shack seems to have a really odd history of building outdated (albeit confortable) gear using outdated material (velcro), and now, with the speedbag, outdated, decades old designs. Of course they will tell you that they have done thousands of tests that show that they are smarter than the other 95% of the industry who tend to do things similarly. Are the other 95% sheep? Hardly. Is Jump Shack leading edge, pioneering new designs that others haven't figured out yet? History shows that is clearly not the case.

Anyone who has packed a speedbag would surely see the pitfalls of it's design.

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Anyone who has packed a speedbag would surely see the pitfalls of it's design.



I get to a point where I lose the urge to reply to generalized, idiotic posts. I wish I had the tenacity of Mike Forsythe, but I don't.

However, I'm going to reply to this idiotic, generalized comment, and then I'm going to leave this alone, because it's just not worth the effort after this....

I am "anyone who packed a speedbag" and I applaud the design (yes I consult for JumpShack, but that does not impact this statement). I was so impressed with the design that I put one on my main and reserve.

The Speedbag is an evolutionary development from an older design, not a step backwards. I know that statement won't change your mind, because it's obviously already made up. However, that you can make a statement like "Anyone who has packed a speedbag would surely see the pitfalls of it's design." just shows that you also think you know everything there is to know about the subject and that your views must be absolute.

Please don't post a reply to this, I'm not getting into any kind of a battle of wits with an unarmed person, I just couldn't let that statement go.......... now excuse me, I'm going to go and jump my Racer 2K3 with it's speedbag enclosed reserve canopy and it's speedbag enclosed main....... ;)
Pete Draper,

Just because my life plan is written on the back of a Hooter's Napkin, it's still a life plan.... right?

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I don't believe in line dump, (otherwise freestowed lines would always "dump", but they don't) although I do believe that a canopy that starts inflating before it hits line stretch is a serious issue. That being said, the line stow pouch and primary stow on a freebag or tail pocket (base) are exceedingly reliable. The speedbag solves a problem that simply does not exist.

When I received a reserve speedbag as a replacement for a lost freebag, I thought it was a really poor, 30 year old design. Reading about locked bags on this thread confirms what I thought. I had to sign a waiver to get a standard bag.

Jump Shack seems to have a really odd history of building outdated (albeit confortable) gear using outdated material (velcro), and now, with the speedbag, outdated, decades old designs. Of course they will tell you that they have done thousands of tests that show that they are smarter than the other 95% of the industry who tend to do things similarly. Are the other 95% sheep? Hardly. Is Jump Shack leading edge, pioneering new designs that others haven't figured out yet? History shows that is clearly not the case.

Anyone who has packed a speedbag would surely see the pitfalls of it's design.



the design addresses a problem and it is HIGH SPEED reserve deployment. at 275 lbs maybe you should be concerned more. Having read this from top to bottom, I will now order a speed bag reserve freebag for my racer NOS. Thanks for replying Nancy! Nancy replied once before on this subject on Dec 17 2004, here it is cut and pasted...

I have the Mil Spec document that I received from Keener, the manufacturer of Mil Spec Rubber Bands. Jump Shack has sold these rubber bands for as long as I can remember. I will see that it gets posted on the Jump Shack web site, and post it here on Monday. Rubber bands are far superior to the bungee stow for the following reasons. Rubber bands have better retention ability than do the bungee stows. There have been several reserve failures due to line dump/strip that have been attributed to use of the bungee stow, which most riggers don't know or bother to adjust for narrow or wide reserve d-bag. A rubber band will break when it has to (usually between 20 - 40 pounds), thus preventing a bag lock situation. Bungee stows will not break, and are more likely to result in a bag lock on your main or reserve. I have used rubber bands on my own reserve for more than ten years, and would NEVER use a bungee on my last line of defense - my reserve. Mil Spec Rubber bands have been in use longer than the bungee stow has been in existence - some 60 years. We have put rubber bands through the high heat and freeze test during multiple TSO tests. It takes two to three years of extreme temperatures for a Mil Spec rubber band to break down, and frankly, brass has nothing to do with the deterioration. It's a heat and loss of moisture problem. Besides, even if one or more of your rubber bands break on your reserve d-bag, guess what might happen? You might get exactly what you get with virtually every deployment from the old style pouch and bungee reserve bag - a LINE DUMP. For more detailed information read about the Speed Bag (prevents line dump) on the Technical Articles Page at Jumpshack.com.
Hope this is helpful.
Those who don't know history are destined to repeat it.

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wow.

I mean ......

wow.
Quote

I don't believe in line dump


wow.

wait, it gets better.
Quote

I do believe that a canopy that starts inflating before it hits line stretch is a serious issue.



Uh, do you know what "line dump" means? I don't think it means what you think it means.

How do think a canopy is going to start inflating before line stretch if the lines are still in place?!?!?:S

Quote

When I received a reserve speedbag as a replacement for a lost freebag, I thought it was a really poor, 30 year old design.



wow.

When we have mentioned diapers in this thread, it is to make refrence to having elastics used on the line stoes and thier proven reliability, not the speedbag design.

And just FYI, the safety stoe was released in September of 1983. I'll say that again September of 1983. That makes the old design 23 years old! Speedbag design is far less than that!

Quote

Jump Shack seems to have a really odd history of building outdated (albeit confortable) gear using outdated material (velcro)



wow.

Hey dude, the 90s called. They want thier Racers back.
This is a prime example of someone who has no idea what the hell he's talking about spouting opinions. The worst part of this is that there are jumpers who are gonna buy the crap he's spewing.

I'm guessing you haven't seen a Racer recently (beyond an old model from the last decade or more)

The riser covers DO NOT HAVE VELCRO
The riser troughs DO NOT HAVE VELCRO
The toggles DO NOT HAVE VELCRO
The main flap DOESN'T HAVE VELCRO

But god forbid you should get informed before stating your opinion as fact.

I'm reminded of an old saying "It's better to say nothing and be thought a fool than to say something and remove all doubt"
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.

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I think you will find this is not a "generalized" comment. It is a legitimate request for information about statements made by Jump Shack.

Nancy seems to have chosen not to respond. If you have any of the facts maybe you would like to comment.

Quote

All the major manufacturers use "special" bags wherein every stow is a locking stow so that the canopies will take the vicious openings encountered when you static line a 97 sq ft reserve with a 300 pound load at 180 mph! Then those canopies go out into the field where they are assembled into bags that practically guarantee a line dump.


How do these manufactures deal with the requirements of AS8015-B sections 2.1.2, 4.3.4, 4.3.4.2, and 5.1?

Quote

There have been several reserve failures due to line dump/strip that have been attributed to use of the bungee stow, which most riggers don't know or bother to adjust for narrow or wide reserve d-bag.



Quote

The one case (that I know of) of a freebag that bag locked involved a bag with a BUNGEE STOW that would not break.



Quote

There've been several instances where lines tore from reserve canopies, or canopies blew up as a result of line strip. It's not that the canopies were not built strong enough - it's that the deployment system did not meter the lines out in a controlled manner, and sufficiently soften the opening. There has been more than one fatality as a result.



Quote

Recent student harness failures are the direct result of line strip openings



Where would I find the facts on the incidents mentioned above? How were these conclusions determined? Why can I find anything about the investigations?

If you don't have any of the answers I am looking for that is fine, but I don't need to be called and idiot or mentally unarmed.

Sparky
My idea of a fair fight is clubbing baby seals

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Back to the point-- Two rubber bands are not strong enough to safely contain a canopy in the bag during bag lift. The safety stow is. Canopy dump is more dangerous than line dump. Although the speed bag is a good idea compared to a two rubber band stow bag, a safety stow is better in that it will release both sides if just one stow clears. The speed bag does meter out the lines far better than a line stow pocket. There you have it, make your choice.

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