Power Kite Forum

This "old" kite

pongnut - 18-6-2013 at 09:34 AM

I've had my PL Twister 5.6 for more than a couple of years now and I suspect the bridle may have stretched a bit, and the ripstop isn't as crispy as new. I still love this kite and wan't to get many more years out of it. So, just wondering if those kite repair places can assess and tune bridles?

indigo_wolf - 18-6-2013 at 10:26 AM

The ripstop can be retreated and and the bridle segments can be checked for stretch. If your seeing a lot of bridle wear, you might be better off just replacing the bridle outright.

Ozone has established SKU number for replacement bridles, but for whatever reason PL doesn't list them on their Retail Pricelist. Any authorized PL deal should be able to get a price quote for you though.

ATB,
Sam

DAKITEZ - 18-6-2013 at 02:28 PM

I would start measuring bridles. Compare the left side to the right side. If everything stretched equal you have not problem. But if a few bridles stretched more than another you can simply add a knot in the bridle line to make it the same length as the other side.

pongnut - 18-6-2013 at 02:45 PM

I guess I'm not too worried about left/right symmetry as much as I am that the AOA may have changed slightly, causing the kite to sit deeper into the window.

If there are any PL dealers on here who can price me a bridle or at least get me the factory measurements of the bridle segments, that would be great.

I’ve also picked up hints from the forum that the ripstop itself can also "stretch" over time, which would just complicate things further. I don’t think my kite has seen enough stress and history to have stretched the fabric yet - but that’s just an assumption.

Thanks

DAKITEZ - 18-6-2013 at 02:49 PM

have you checked the power lines vs the brake lines? It could be very common for the power lines to stretch and the brake lines to stay the same. This would put more drag on the kite causing it to sit further back in the window.

Bladerunner - 18-6-2013 at 04:56 PM

I am confused by what you mean by deeper ?

Are you saying it seems like you think you have stretched B and C rows ( 2nd and 3rd ) ? Causing the kite to fly more forward in the window? Twister already flies pretty far forward. I would think you would get overfly / nose tuck if this was the case?

Are you saying the kite doesn't fly as far forward now and sits back in the window ? If so Dino is right, check your fly lines 1st. ( anyway )

If you want it checked out proper then I would suggest contacting Powerzone. John is very good at tuning bridles. He also sells that spray coating that Big Kid introduced us to.

If you want to seal the kite There are a few products out there and lots of discussion. Something about silicone and vinegar as a DIY way. Jeff, John ( probably Dino? ) and many shops have the spray coating.

3shot - 18-6-2013 at 05:10 PM

Really far fetched but I wonder how that spray (not Scotch Guard) for nylon camping tents would work? I think that stuff is silicone base too. It's a water repellent coating.
Course, it's just as easy to use the correct stuff anyway I guess. Just thinking....

indigo_wolf - 18-6-2013 at 06:55 PM

Pretty sure Coleman and other tent sealants tend to be a bit heavier which may be a concern for light wind characteristics.

NikWax TX.Direct Wash-In might be a better choice.

Also, BigKid was piloting the Kite Refit product.

ATB,
Sam

pongnut - 18-6-2013 at 07:02 PM

Sorry, yeah, deeper in the window meaning, sits back in the window. And this is with totally slack brake lines.

Yeah, that kite spray that BigKid posted about is definitely on my radar...

Thanks.

Prussik - 19-6-2013 at 08:43 AM

The tendency of Dyneema and Spectra lines is to shrink (not stretch) over time when loads are low as is the case with bridle lines and brake lines. This tendency is counteracted by the load on the power lines.

Scudley - 20-6-2013 at 05:33 AM

Quote: Originally posted by Prussik  
The tendency of Dyneema and Spectra lines is to shrink (not stretch) over time when loads are low as is the case with bridle lines and brake lines. This tendency is counteracted by the load on the power lines.


Are you sure about this? I can't find any technical data sheets about this property for Spectra, I do see mention of it in forums, but not in any tech spec and there is lots about "creep".
S

RonH - 20-6-2013 at 05:23 PM

Quote: Originally posted by pongnut  
Sorry, yeah, deeper in the window meaning, sits back in the window. And this is with totally slack brake lines.

Thanks.


Sure sounds like the bridle has stretched,,,

A complete bridle with be $$$. But you can have a dealer check it out.

pongnut - 21-6-2013 at 06:10 AM

I don't mind packing it up and shipping it to someone for evaluation - should I send it to a PL dealer (any on PKF?) or Powerzone?

RonH - 21-6-2013 at 08:17 AM

Quote: Originally posted by pongnut  
I don't mind packing it up and shipping it to someone for evaluation - should I send it to a PL dealer (any on PKF?) or Powerzone?


I meant for a dealer to check on the price of a new bridle...

I'm sure you can get the bridle plan from PL and see what's wrong. Then you could send it out for repairs (along with the dimensions) to someone if you don't feel comfortable making the adjustments yourself.

Ron

Prussik - 21-6-2013 at 09:47 AM

UHMWPE is very stretch resistant (Spectra more so than Dyneema, I think) and this characteristic is the one emphasized for the common applications. Less is being said about shrinkage which can be of consequence only in some “exotic” activities such as paragliding or kiting. Whether the line stretches or shrinks depends primarily on the load level and duration but higher temperature promotes shrinkage. I have observed shrinkage in brake lines as well as in bridle lines. Brake lines are easy to take care off, bridles – less so but the relative lengths remain close enough ( for me, in most cases ) to not change flying characteristics appreciably. The same would apply to stretching, though the bridle loads are low so this is less likely but possible. It depends a lot on the state of the lines at time 0. If handling is suspect it is worth looking into both possibilities keeping in mind that stretching of some lines will have the same handling consequences as shrinking of the others.

Scudley - 22-6-2013 at 07:24 AM

Prussik, I breathlessly await your article on materials that experience compressive strain in the direction of a tensile load, 'cause it's going to be earthshaking; whole branches of science and engineering will have to change their models. Take that Robert Hook.
S