Reducing Core XR3 12 bar pressure

[direnc]

Hi,

I have a Core XR3 12m kite, the bar pressure of which I find too much. It's already setup to have the least amount of pressure, and front/back lines are equalised on the bar. It has a bridle like the image below. I wonder if there's any mod to make the bar pressure lighter. As light as an 11m edge possibly ?

[PullStrings]

Hello have you owned this kite since it came out during the summer of 2013 ?
Are you using a Core bar ?

What's happening is that the leading edge casing has become quite soft / flexible over time from UV rays... salt air....elements... etc..it has lost it's coating that made it stiffer
The kite's shape when riding becomes " spread out "/ distorted from when it was newer....the result is the wingtips are more spread apart pulling too much on back lines

You can help the kite have a curvier leading edge shape by " crunching it " .....putting the " C ' shape back into it
Let it rest/flying on the sand on it's wingtip at the edge of the window 30 seconds..do one side of the wingtip then the other side...this will bend the LE properly and kite will fly better

An other thing you can do is attach your back lines on the wingtips at the slowest mode/ further away from tips...this will put less tension on the back lines...kite will still turn fast
Also lengthen the back lines at the wingtip long pigtail and under the floats

Having all lines equal on bar is "OK "but you need overall tuning with old XR3 soft leading edge ( that's why Core XR4 and XR5 was improved and made with Exotex ultra rigid dacron casing )

Try all those tips....oh yes... and also ...put about 8 to 8.5 PSI when pumping....6 to 7 PSI is not enough
Give us back a report

[direnc]

It's a second hand kite. I tried an XR4, liked it a lot, and got this believing it was basically the same kite, but not really it seems...
I tried it with a Core Bar, and another one with a low Y, but the bar did not make much of a difference on bar pressure .
The back lines are already setup the way to make the bar pressure the lowest possible.
I thought the bridle should keep the C shape the way it should be, but will try the method you suggest.
If the kite being more spread out is a problem, maybe a bar with a higher Y might help pinch it a bit more?
Any way to alter the leading edge bridle for lower bar pressure?

[PullStrings]

The back lines are already setup the way to make the bar pressure the lowest possible.
If the kite being more spread out is a problem, maybe a bar with a higher Y might help pinch it a bit more?
Any way to alter the leading edge bridle for lower bar pressure?

For an XR3 with worn out stiffness of LE casing you should attach the back lines in medium wakestyle mode to get lowest bar pressure...and make them 2-3 inches longer
Higher "Y" won't really help control the LE softness situation
Altering the bridle won't really help the bar pressure
XR2 had similar issues by the way when it came to bar pressure increasing as the kite got used a lot and old
No doubt XR4 & XR5 are better at reducing bar pressure and keeping it low not only because they are newer but because of Exotex rigid dacron

[GregK]

Any way to alter the leading edge bridle for lower bar pressure?

Yes, modifying the front bridle to move the front tow point ( the point at which the front flying line is attached ) slightly aft and closer to the CE or centre of effort ( the point on a sail at which application of the whole propelling force of the wind would produce an effect identical with that produced by its distribution over the whole sail - https://www.merriam-webster.com/diction ... f%20effort ) will shift more of the kite's pull from the back lines to the front lines.

Warning - moving the front tow point to, or aft of, the CE and you lose the ability to depower the kite. For this reason, most prefer not to tinker with the bridle and instead replace the kite with one that has lower bar pressure.

[direnc]

Yes, modifying the front bridle to move the front tow point ( the point at which the front flying line is attached ) slightly aft and closer to the CE or centre of effort ( the point on a sail at which application of the whole propelling force of the wind would produce an effect identical with that produced by its distribution over the whole sail will shift more of the kite's pull from the back lines to the front lines.

So, how do I move the tow point on this bridle? It has two pulleys and a slider on each side. Is it possible without adding new bridle attachment points? Just by changing lengths of bridle segments?

[GregK]

OK, # 1 rule for bridle mods : " Patience you MUST have " ( Yoda ) 2nd rule : Safety, Safety & safety.

First mod to try - move the top or inboard connection of the B2 pulley line down one connection point. Because the leading edge sweeps aft as well as outboard, this will have the desired effect of a slight aft movement of the tow point. This will also make the front bridle a tad longer than the back, so either trim the depower at the bar a lot or add a few inches of pigtail onto the back line.

Ensure your bar's chicken loop release and leash release are working perfectly, then on a steady and gentle ( 9 -12 knot ) wind day, at a safe spot with no hazards ( hard objects, by-standers, boats, deep water ) for many kite line lengths in all directions, test fly it, starting with gentle movements & changes in bar trim progressing to more aggressive flying. If it works as desired in light wind, try again ( at a safe spot ) in medium wind, etc ...

If the bar pressure is still to heavy with the bar powered-in close to the chicken loop, move the top connection of B2 down/out another kite connection point. Front bridle will get a little longer, so either more depower at the bar or a bit longer on the back line pigtail.

Pump the kite up hard to avoid the LE folding at these lower B2 connection points that will now be closer together. Usually LE tip folding won't happen in gentle flying but when you load it up in a heavy kite-loop or similar high-power dive & turn.

If you wind up with both B2 lines around the last / lowest / most outboard attachment point and it's still to heavy on the bar, put the bridle back to factory and sell it to some Charles Atlas guy who loves a kite with solid bar feel, or spend money adding a pair of new bridle point further out / down.