RMURRAY 1 #26 December 15, 2004 QuoteQuotewithout shopping for the best price - I bought them from JumpShack. Is that the only source? How do they differ from 'normal' rubber bands that you can get from Para Gear? I don't know.... I would really like to see the mil-spec on them and compare the para-gear rubber bands to the mil-spec requirement, see how they stack up. I'm glad I don't have to deal with this issue since I won't pack Racers. I'm just curious as to the differences. Derek I am sure you can buy them elsewhere. I'd like to read the spec too. It is no BIG deal - I bought a pound, use them for my main as well (and give them away anytime I can)...rm Quote Share this post Link to post Share on other sites
NancyJ 2 #27 December 18, 2004 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. Quote Share this post Link to post Share on other sites
riggerrob 561 #28 December 18, 2004 To summarize, safety-stows work best near the low speed edge of the reserve deployment envelope. Jump Shack's "Speed Bag" is most valuable near the high speed edge of the envelope. As for your customers who "pencil pack" beyond the (2 or 3 year) life of rubber bands: that's their problem. Quote Share this post Link to post Share on other sites
RIGGER 0 #29 December 18, 2004 Enclosed some information from "Keener" the mfg. of Mil Spec rubber bands which I use for years. I got the Rubber Bands I use for the Racers from Jump Shack this is the way I got the Mfg. approved rubber bands. Enclosed information from "KEENER" web site: http://www.keenerrubber.com/Parachute.htm http://www.keenerrubber.com/Glossary.htm http://www.keenerrubber.com/natural_rubber.htm Excerpted Specifications for Mil-PRF-1832E Type I and Type II Parachute bands http://www.keenerrubber.com/mil_specs_.htm I hope this helps. Regarding the Brass grommets/Rubber Bands I did found that even Mil Spec. rubber bands are effected by the brass & I always replaced the brass grommets with Nickel plated same size grommets & washers. Safe Rigging !!! Quote Share this post Link to post Share on other sites
mjosparky 3 #30 December 18, 2004 QuoteRegarding the Brass grommets/Rubber Bands I did found that even Mil Spec. rubber bands are effected by the brass & I always replaced the brass grommets with Nickel plated same size grommets & washers. Did you get written permission form the manufacture before you made this change to a TSO'd part? Your quote from an earlier post. QuoteIf a reserve canopy mfg. TESTED & TSO'd his reserve with metal links only that mfg. can give the approval for the change. SparkyMy idea of a fair fight is clubbing baby seals Quote Share this post Link to post Share on other sites
