Hi all

I haven't been winging for long but I'm starting to think about my setup, specifically the pressure I put in my wings. I have a Konrad V1 6m which I pump up to the 8psi specified as my gauge reads. I have never really thought it had much oomph when pumping onto the foil but had nothing else to go by.

I recently got an Echo 4m and the first day I took it out in 20 to 25 knots, pumped up to the specified 6psi. Now I'm 100kg's, and as soon as I launched I knew it was under inflated. The loads I was putting on the wing was flexing the tubes up and I was loosing power and stability. I sailed straight back in and pumped it up to 8psi on my pump and it immediately felt better. Now I'm thinking that I'm not inflating my Konrad enough either but the bigger more stable leading edge tube is hiding it from me.

My question is, do the pump gauges normally read wrong by a percentage or by a fixed amount. The 6psi to 8psi increase I used on the Echo is a 25% increase which would give me approx. 11psi for the Konrad if it's reading under by a percentage. If it's only reading 2psi under then it means I only need to go to 10psi on the Konrad. It seems like that extra 1psi is a reasonable difference, would I feel this in the stability of the wing?

Hopefully I will get a chance to be inflating at the same time as someone else and I can swap pumps and compare reading but for now I'll be solo.

Thanks
Jethrow

P.S. There was a thread somewhere that I can't find now where someone was talking about using a guitar tuning app on his phone to flick the tube and get a tone reading that could be reproduced without a pump gauge. Anyone else heard of this?

Pump gauges are totally unreliable, and their reading can vary in time.

To the point that Gong now does not even mention a recommended pressure on their wings anymore. They made this video in April, It do not know if it was the one you saw:

See how he judges the pressure from the leading edge flex at 0:42 and the sound when knocking on it



He also says elsewhere that his 50 kg son likes his wings more inflated than him: at 100kg, he likes them less rigid for a more efficient pumping. So he says that the pressure will depend on each rider tastes, but they each keep the same on all wind ranges.

For inflatable SUPs, the pressure is less critical: I just bought a precision gauge for car tyres ($20) and an adapter so I can calibrate my SUP pump from time to time.

I started kiting in 2006,
I have hardly ever used a gauge but always pumped up my kites and now my wings as hard AF*
I have only ever blown a couple of kite bladders and they were due to extreme circumstances, eg broken harness hook mid kite loop and tomahawking my kite into the water at full power or dropping it right in the impact zone in decent sized surf.
Kites and wings performer way better when they are hard IMO.
I don't usually use a gauge but I pump them up hard and just do the finger flick, ping test.
I honestly think more damage is done by under inflating.

*I take no responsibility for damage caused by following my recommendations

*edit - If I am going to leave my kite/wing on the beach in the sun for any length of time I will let some air out.

I have often thought about this issue and wondered why they don't have something like what they use on a medical infusion pressure bag.. They have a simple slide out button that shows a line or colour when pumped to the correct pressure.

mcrt said..
Sounds very logical :)
So gauges are unreliable therefore we will inflate by ear, super exact method.Who does not have perfect pitch huh?.

If you actually watched the video, you would have seen that he uses the way the fabric folds under pressure, which is visually quite obvious.

The noise is an ancillary test, as a precaution afterwards.

To tightlines:
The difference between kites and wings is the relative diameter of the leading edge.
When a kite folds under pressure (hitting the water), the increase of pressure is much less than when a Wing is folded.Just try folding a thin balloon wrt a thicker one. And the placement of the handles in wings make the leading edge fold in two if you do not let go in falls.

This means that over-inflating a wing is much more likely to make it explode in action than a kite.

mcrt said..
I did watch the video Colas, when it came out.

Then you saw that the visual check by folding starts a 0:42, and sound test happens only briefly at 1:20.

And I am sorry, but the cheap gauges are very sensitive to moisture, salt, dirt, sand, plus they are not measuring the air pressure inside the chamber, and they are exposed to constant accelerations as being on the handle and not the body. All things making them less reliable than a folding test. I have been windsurfing for years, and the human senses can reliably judge the various tensions needed for rigging.

If you prefer an exact measurement, just buy a quality pressure gauge + an adapter. It will also allow you to get a reliable pressure for your car tyres, which can be life-saving.

Yeah. I was a bit concerned if I was putting too much air/pressure in my wing.
Then I found on the internet it was said that you read the pressure as you push or pull, (I prefer push), on the pump as air goes into the wing being the right pressure that you read. Obviously no pressure reading when you stop.
I would like to see a gauge like a tyre pressure gauge that would give you an exact reading if you are fussy. A tyre pressure gauge needle will stop at the right reading when forced onto a valve. Maybe the adapter that Colas mentioned does this.
But it hasn't taken me long to find that I pump my wings to an acceptable pressure by viewing first the max pressure the gauge gets to on the down stroke of my pump. Then I will press & feel the hardness of the leading edge each time before going out.
If my session was good on the water & the feel & performance of my wing was good also. Then I just repeat the same process next session.
I think after a while you will know the difference between the gauge & your feel.
That being if I used another pump with a faulty gauge then I will know by my feel if it's the right pressure.
I did this same thing with bicycle tyres. Never bothered with a gauge. The harder the tyres the faster the bike would go. But there is a limit........... BOOOM!!!

I've been using these two 0 - 15psi gauges for almost a year now and I don't like the oil filled anymore, as low temps make it too slow to get a accurate reading when pumping with the check valve fitting. Also the oil filled needs to be burped from time to time. But the digital has been prefect.

I will be replacing the oil filled with a second digital gauge. Maybe redundant but for $15 bucks... The thing with the digits is you can accidently switch it to KPA, BAR or... So having 2, you are just looking that they both read the same, and that should do it. Oh yeah the accuracy is spot on. Compared to original gauges being off by OVER 30%.

mcrt said..
That is a cool pump.
How much is a digital gauge like that cost?

There $13 usd on Amazon now.
www.amazon.com/MEASUREMAN-Pressure-Connector-Protective-0-200psi/dp/B08FB2G3T8

colas said..

Seajuice said..
Maybe the adapter that Colas mentioned does this.

Less than $10 for 4 adapters... Example:

www.amazon.com/Alon-Inflatable-Conventional-Multi-Valve-Attachment/dp/B08BNS8BNH/

Thanks Colas. Much appreciated. If I use one of these, it will be simple for me to push my hand held tyre pressure gauge onto it after pumping the wing up. My hand held pressure gauge locks the measuring needle at the pressure reading even when I remove it.

Gorgo said..

Fishdude said..
...

Oh yeah the accuracy is spot on. Compared to original gauges being off by OVER 30%.
....

How do you know the accuracy is spot on? You can only get a pressure reading during the up or down stroke and that varies depending on how hard you're pushing the pump. If you're not pushing then you're measuring the pressure in the hose and that's very transitory.

I tested all the gauges against a column of water 25 feet tall in a test rig. (27.707 inches of water =1psi...) test them at different pressures 13.8' =7si ...

As far as stoke of your pump and the accuracy of your reading, well that could be subjective with different pumps or your wing's check valve and they way you use it. I personally haven't noticed any issues with my readings worth any concern IMO. The slow long stroke seems to give a nice steady increasing psi reading that looks right in my experience. But if wanted, you could test it by putting a test connection between the check valve and the wing to see if you have a discrepancy which would give you an idea if it's really a issue. Maybe there's something that, but the gauge works for me.

colas said..

Seajuice said..
Maybe the adapter that Colas mentioned does this.

Less than $10 for 4 adapters... Example:

www.amazon.com/Alon-Inflatable-Conventional-Multi-Valve-Attachment/dp/B08BNS8BNH/

I'll order one of these adapters to answer this curiosity that Gorgo asked about.
See if I can just put a gauge directly on the adapter. Use that to double check psi after inflation.

My 2021 Gong wing has 2 inflation points (ones a deflation point on the strut). So I check that one directly as I inflate it at the other inflation point. I'd be surprised if it's more than 0.3 psi difference from the pump reading.

colas said..
Pump gauges are totally unreliable, and their reading can vary in time.

To the point that Gong now does not even mention a recommended pressure on their wings anymore. They made this video in April, It do not know if it was the one you saw:

See how he judges the pressure from the leading edge flex at 0:42 and the sound when knocking on it

He also says elsewhere that his 50 kg son likes his wings more inflated than him: at 100kg, he likes them less rigid for a more efficient pumping. So he says that the pressure will depend on each rider tastes, but they each keep the same on all wind ranges.

For inflatable SUPs, the pressure is less critical: I just bought a precision gauge for car tyres ($20) and an adapter so I can calibrate my SUP pump from time to time.

I like this video certainly is helpful, but it may have even been more helpful if he used a sand bag of a certain weight. 20lbs, 10 kg or whatever could be just a little better reference than pushing on it.

Looks great Fishdude!.
That's what i am going to make, and that is what we should be getting with every 800? wing :)

marcusw said..

Fishdude said..

colas said..

Gorgo said..
Do those adapters fit kite valves? The tapered one on the left would fit in a Boston valve. The bayonet valve look more specialist.

I don't know (I dont kite... nor wing).
My point is: whatever your valve, be sure that an adapter exists, just look around.
You can ask the vendors the question, and return it if it doesn't fit.

"How do you know the accuracy is spot on?" - My more primitive method without any pump mod: I just put the digital gauge directly on my inflated SUP with the adapter. So I measure the actual pressure in it. I can then compare with the reading I get on the built-in pump (when inflating slowly) and know its offset.

Colas, I put together your adapter with the gauge to read directly off the wing, works great. It reads about 0.15 psi lower than my pump. But my adapter fitting leaked a little so it might be even closer when I seal that leak.

Hi Fishdude, this looks great, I'm going to try to do something similar. I see you've threaded the gauge into the adaptor. Did you remove the male threaded piece from the adaptor first? Was it easy and did you have to retap the plastic? Also, did you just glue the stick onto the kite/wing valve side of the adaptor to push open the check valve in the kite/wing?

It's a great setup you have. It will definitely get the pressure in the kite/wing within a couple of % every time.

I particularly like that you tested the pump and gauge against a 25 ft manometer!!

I had to remove the standard tire valve by drilling it out which was a little bit of a pain. Then drilled up to size (7-/16 drill or just a bit smaller works) and threaded it for the 1/4 NPT gauge.
For my Takoon and Gong valves (I don't know the name of those types of vales) I JB welded a nail in place and cut and smoothed it just long enough to unseat the rubber flapper about 3mm. Was perfect for opening flap without letting any air out of that valve.

The fact that the gauge on the pump was within 0.2psi what I read of the stand alone reading gauge, should be good enough. Note the readings in the photos were just random and not related to what I tested. It's impressive how consistence those digital gauges reading are.

colas said..
To tightlines:
The difference between kites and wings is the relative diameter of the leading edge.
When a kite folds under pressure (hitting the water), the increase of pressure is much less than when a Wing is folded.Just try folding a thin balloon wrt a thicker one. And the placement of the handles in wings make the leading edge fold in two if you do not let go in falls.

This means that over-inflating a wing is much more likely to make it explode in action than a kite.

I still stand by my statement that more kites and wings are damaged by under inflating than over inflating.
The harder it is inflated the less likely it is to fold in the first place.
When they are soft every time you pull on the handles to try to pump for a wing or load up the kite for a jump the strut/LE is flexing.
Or if hit by a wave they fold in half etc.

That is just my opinion after 15 years of kiting and 2 years of winging....

I do agree with you though that pump gauges are unreliable, I would much rather trust feel, ie how hard it is to pump and how it feels/sounds with the flick test.