Spectra Lowers

[hamsandwich]

Who's tried using 1000# spectra for their lower control lines? Someone must have.

Is there a finer degree of control without the stretch or is it not noticeable?

i was thinking 1000# spectra lowers with captive loop break settings. The break settings shouldn't ever blow up. And since I don't do hardly any slider up, friction on the spectra wont be an issue. for the few that i do, the captive loop on the spectra wont catch on the guide ring like dacron would.



-a

[nicknitro71]

Dude,

WHY? What are you going to gain? Spectra is the worst idea for any canopy. For Tandem and BASE it sucks because it does not stretch. For the rest of the population it sucks because the tarp goes out of trim in less than 100 jumps.

Stick to Dacron and if you want less drag go HMA but the lower control lines should always be Dacron due to its excellent abrasion properties.

Read here before going Spectra. Spectra should only be used to hold toilet paper rolls.

http://www.egwingsuits.com/Articles/...Comparison.pdf

[nicknitro71]

Hell is a captive loop? Do you mean a cateye? If your dacron loops catch the ring then they are made wrong.

Don't get me wrong, for slider down you can go Spectra but again why?

[Johnny Utah]

Who's tried using 1000# spectra for their lower control lines? Someone must have.

Is there a finer degree of control without the stretch or is it not noticeable?

i was thinking 1000# spectra lowers with captive loop break settings. The break settings shouldn't ever blow up. And since I don't do hardly any slider up, friction on the spectra wont be an issue. for the few that i do, the captive loop on the spectra wont catch on the guide ring like dacron would.



-a

I've never tried spectra on only the lower control lines (but I have tried the spectra on all the lines). Abbie I find your idea an interesting one. As I'm sure you know spectra on the suspension lines make the canopy open too hard because spectra doesn't stretch like dacron. But having spectra only on the lower steering lines may work out as good or better on the openings. The slider might come down quicker on sub-terminal jumps with the less friction. As far as the wear. Can't hurt to try it out and see how they hold up in the BASE environment. My guess is they may wear out quicker but I find myself constantly having to replace dacron lowers so who knows if it would be the same, worse, or better.

One thing I would be concerned about though is putting the toggle tab through the eyelet on the spectra line like on a slider up configuration because a hard opening could cause the skinnier line to dig into the toggle and hang up. You can still use the riser loop with slider up but then again that may increase the chance of a hang-up.

[lifewithoutanet]

Okay...I'm stepping into the ring without a rigger's ticket and without much practical rigging experience...so go easy.

With Dacron being in the range of 11-13% elongation and Spectra at 2.7-3.5% (dependent on type) and being a part of a dynamic system, how much of a factor is elongation where Abbie's original question about degree of control is concerned? How about opening shock?

I don't see elongation becoming a factor where control is concerned. Any miniscule stretch will be well within the range of motion of the jumpers arms. I don't imagine any significant elongation even on opening, given that this is again, part of a dynamic system. The forces are distributed to all of the lines, as well as having an effect on the airfoil. Just seems that it really would be negligible on BASE canopies. Of course, going to Spectra on all lines would transfer more energy directly to the canopy itself, thus the hard openings.
Apart from what Johnny mentioned with friction on the slider, I don't see a significant reason to do it.
-C.

[hamsandwich]

spectra lines for the whole canopy i dont like unless you're building a rig just for ultra low freefalls. CR offfered (maybe still offers?) spectra lines but they warned of very hard openings.

nick, your foreskin is a captive loop. attached is a picture of what i meant. its a skydiving style loop. if you do it with think dacron there's a nub that can catch on the guide ring.

the goal would be brake settings that don't wear out as easy and maybe some crisper input as a side benefit.

Johnny, could you explain what you meant about the toggle hanging up. I didnt quite visualize that. GOod to see you online bro. Congrats on your move to FL!

[mknutson]

I think at 4 seconds slider down, with Spectra, your going to get the shit kicked out of you.

[lifewithoutanet]

I think at 4 seconds slider down, with Spectra, your going to get the shit kicked out of you.

Hell yeah. But the original question was just lower control lines.
-C.

[mknutson]

Hell yeah. But the original question was just lower control lines.
-C.

SO i'm slightly off-topic.....

[vid666]

ok,

I have to (painfully) side with nicknitro. Spectra seems like a stupid way to look for performance. Why not go with Vectran ? BigAir used to make vectran steering with their microlined canopies. Seems like a more solid idea.

and the old Vetigo Dragon was microlined (at least the one that i saw) - and it was a slammer..

[nicknitro71]

Abbie,

The pic did not go through.

So you want less wear right? Then go Dacron because the abrasion resistance is better than Spectra. With a properly done CATEYE loop you should not feel any notch. I don't see why you want to make a loop in any other way than the cateye, it has lower bulk and it's flatter than any other looping method.

The only thing you gain with a Spectra lower is a less bulk.

If it ain't broken don't fix it!

[hamsandwich]

oops. sorry. I added the attachement to that post and again here.

[nicknitro71]

This method adds additional bulk. Stick to the cateye.

[hamsandwich]

aiight. I got the cat's eye, now what do I do with it...

thanks for da input!


-a

[nicknitro71]

Saute' the cat eye in olive oil with red onion, lots of garlic, and a bit of parsley. Then add fresh tomato, and a sprinkle of white wine, pinot grigio preferably. Cook for five minutes and then stick it up your ass.