New Tech Kites

dagnabbit · Wind Seeker Joined: 22 Mar 2006 Posts: 9

I just bought what I think was the last new (old stock) Firestorm around, from a kite vendor that had one in his trailer at a kite fest I went to recently. Too cool- big, slow, noisy, pulls like a truck and dwarfs everything flying around you.

I had to do some repair to a lower leading edge spar (gotta make sure they're fully seated when you put them together- DOH! ), and I decided to stop using the supplied bungie to attach the sail to the ends of the spars. I used a couple of loops of 200# dacron, and made tension loops like my New Jam uses. It's a lot tighter now, and a lot quieter.

One of the reasons I like this kite is that it was LOUD using the bungies for sail tension- lots of slack in the trailing edge that way. Has anyone had OK experiences running with the bungies, no increased sail wear, tattering of the trailing edge, etc.? Or- has anyone else tightened down the slack on the trailing edge?

Thanks,
_________________
-Ben

Albert · Wind Seeker Joined: 18 Apr 2006 Posts: 9

I don't know Ben, but I thought I'd give your post a bump. Maybe someone that knows better will come along. I looked up the specs on the Firestorm. WOW, that's a Big kite.

All I have to offer are a few thoughts based on my background in mechanical engineering, and my experience as a skydiver and a little parachute rigging. I have 269 jumps.

From an engineering standpoint, noise = vibration = bad. Vibration can lead to material fatigue and failure. Some materials, like steel, have a stress threshhold below which it will not fatigue. Some materials like aluminum don't and will eventually fail, but the lower the stress, the longer it will live. I don't know about nylon fabric and carbon rods, but I've seen enough tattered flags to think that constant fluttering isn't good for fabric. On the other hand, a little give in the sail probably reduces the stress on the frame. All this may be largely irrelevant though for the following reason:

Sunlight kills nylon. Skydivers are fastidious about keeping their chutes out of the sun when not in use. Nylon will lose about 40% of its strenght after 250 hours of direct exposure to sunlight and 65% after 500 hours. So eventually, your kite will kick the bucket.

I guess what it all boils down to is if it makes you happy, do it. That's what kites are for. If you like the noise, go for it. On the other hand, a tighter sail will probably make the kite more responsive, and I suspect lengthen the life of the sail. Spars are a lot easier to replace.

Albert
USPA C-17###