REV bar line length

Ryan · Since 14 Jul 2005 538 Posts Oregon Addicted

should all four lines be the same length?

when checking this is the depower all the way out? and the bar is pulled all the way in to the top of the chicken loop?

thx

Kataku2k3 · Since 14 Aug 2005 3754 Posts PDX-LA Videographer

Yeah, exactly... Depower all the way out, the lines should all be even when the bar's pulled in. My bars aren't absolutely perfect that way though... The 11's rears are slacked just a hair (maybe 1/2"), and my 9 and 7 are slightly oversheeted. Not a biggie though. Just make sure your fronts are even. That 800lbs line is harder to get pre-stretched from the factory, it seems.

trevorsmith · Since 25 Apr 2005 501 Posts PDX Addicted

Kodiak · Since 01 Aug 2005 1114 Posts Slidey

I have knots in the front lines of pretty much every bar.

I also have a knot in one of my outside lines, since I dont see any other good way to adjust to make the outside lines even.

Since the front and back lines are tied together through a pulley though, I ussually check line lengths by connecting my front line to the outside line on each side and making sure that each pair of lines is the same length total. I just make sure that I always connect the same front line to one side of the kite.

Kataku2k3 · Since 14 Aug 2005 3754 Posts PDX-LA Videographer

Damn, Trevor... That's insane. You doing Figure-8s or just Overhands? The most I've done in anyones is 3 Figure 8s, though none of my bars have that many.

Jim, I'd be a bit sketch about doing anything to the outsides, only because they're thinner (and knots don't make as much of a change in them). The better way to adjust them would be to undo the stitching, slide the sleeved ends, then retie. Either way, I'm sure it works, just wouldn't want to lose 30% of a 500lbs line.

trevorsmith · Since 25 Apr 2005 501 Posts PDX Addicted

Just a regular knot..so i guess you call that overhand? But yeah it is stretching a ton every session. Phil and I fixed them 1 session at Savuie's, the next day rode at Sauvie's and they were all uneven again.

I will take a look tonight, and see how much 2 sauvie's + 1 rooster session stretched them.

pkh · Since 27 Feb 2005 6549 Posts Couve / Hood Honored Founder

Yeah I have probably 6-7 knots on one side on both of my two main bars.

They must have pre-stretched one line but not the other, I can't think of why else only one line would get so stretched. Considering I unhook my bar every time so no chance of it being bias on one side of the kite.

I do like that the 800lb stuff is strong enough you can just tie knots in it though, that makes adjustments easy.

The rears you can just tie up to something stationary and pull hard on to stretch back to even. Or tie a knot on the sleeved area or leader if its really bad.

Nak · Mon Sep 15, 08 5:31 pm

I'll try and do some tests in the next few days and let you know how much strength you lose by tieng a knot in the 800# line. I'm going to guess you end up with about 250# strength. That's still pretty strong, 2 lines means 500# capability. People using Q-line do fine with a lot less. EDITED TO CORRECT: The figure 8 knots most use with that has about 250# strength.

One way to increase knot strength is to use Jerry Brown Spectra adhesive on the knot. That should boost the knot strength up to about 400# -500#.

Subjecting 800# spectra to 400# stretch load permanently stretches 23 meters about 2.5 feet in my experience. That's not pre stretched line, so if your line isn't pre-stretched, it's going to stretch unevenly. If you apply 400# to each of your front lines, they should even out and stay tuned. Don't apply that much force if you have a knot in the line.

Kodiak · Since 01 Aug 2005 1114 Posts Slidey

Yeah, I know I probably shouldn't tie a knot in the outside line, but I did it on my rev bars also, and have never had an issue. If at some point the back line breaks I will just replace it.

Nak · Wed Sep 17, 08 12:44 pm

Just finished a few tests on un-treated 800# spectra line. I tied an overhand knot in the middle of the line and tested it, and tied another knot in the spliced section, the doubled up section, and tested it.

Knot strength in main line: 370#

Knot strength in spliced section: >500#

Obviously, a knot in the spliced section is not going to cause any problems as far as knot strength. Make sure you tie the knot near the loop, otherwise you could weaken the splice.

Knot strength in 500# spectra was tested in a non-spliced section only.
Knot Strength: 150#

One caveat: The 800# spectra used in the front lines of the REV are treated with some kind of wax or something. This will almost certainly decrease knot strength. Probably not a factor in the spliced section, but might be in the main section.

Bottom line: Tying knots in the spliced section of 800# spectra, while not an elegant solution, probably shouldn't cause any problems.

Nak · Wed Sep 17, 08 2:11 pm

Kind of weird, I just checked all 3 of my Bars with stock REV lines, and they're all still in perfect tune? Numerous sessions on each. Are you guys putting some tension on your lines while you check them? Just enough to take most of the sag out of the lines. If you check them on the ground without tension, they can seem to be different length due to variations in the tightness of the weave.

Kataku2k3 · Since 14 Aug 2005 3754 Posts PDX-LA Videographer

Yeah, I'm loading mine to the max. Normally tie one end off to the toe hooks on my car, then lean into it as much as possible.

Nak · Wed Sep 17, 08 2:51 pm

Weird. Some of the lines must not be pre-stretched. Guess I got lucky! Very Happy

Kodiak · Since 01 Aug 2005 1114 Posts Slidey

I have knots in most of mine. They all get tested with me leaning against the bar.

Nak · Thu Sep 18, 08 6:57 am

I came up with a way for those of you without force gauges to pre-stretch your 800# lines with 400# of force. Pre-stretching your lines in this manner should allow your lines to remain in tune almost indefinitely. (You're never going to put 400# on a single front line in actual use.) I'll post pics later, but the basics are pretty simple. Splice two loops in a short piece of 500# spectra. Attach that to your 800# kite line. Hook the end of the 800# line to a strong post, the end of the 500# line to a car. Slowly drive until the 500# line breaks. (With the splice, it will break at 400# to 450#.)

Don't just run out and do this yet. There are a couple of other things to do to keep it safe. There's a lot of force involved, do it wrong and someone could get very seriously injured/killed! You need a safety line, and DON'T use any metal connectors!!! They can become a bullet!

I'll do a thread on this with pics soon.

Nak · Mon Sep 22, 08 1:44 pm

Are you guys testing your line length with the Bungee disconnected? I was playing around with the lines and noticed that the bungee cord could make it seem like the lines were out of tune. (by adding tension to one of the front lines...) Anyway, if you aren't disconnecting your bungee, check which line you're having to tie the knots in. If it's the one opposite the one with the bungee attached, your lines may never have been out of tune.

Disconnect the Bungee at the chicken loop end, leave the end at the flying line connected. (The bungee will hang down...)