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mattkennedy said...
Cheers fellas I actually emailed sir rowdy yesterday as I was chasing some info on the axis boards keen to check em out.
So you run a 17 12 8 quiver glokite. Im about the same weight as you and use my 9m heaps. Whats your go to kite mate

My go to kite in the wet season is the 17 usually blows westerlies and in the dry season it be the 12 and that usually blows eastely. Hopefully a good season this time round so I can use the 12 a bit more and if I'm lucky the 8 for cyclones ( not in the cyclone, more in the edge of of it)

So in the tropics you would go a size bigger than you would normally with the c4??

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mattkennedy said..

So in the tropics you would go a size bigger than you would normally with the c4??

No, air density due to temperature and how it affects the power of a kite is minimal, although imagineers on here will argue otherwise
Buy/Use the same size kite as you normally use.

yeah you do that


then wonder why everyone else seems to be one kite size bigger..

Yep

Then go to a place like Cape Town.
Where the wind is cold and dry.
Then you will wonder why people fly"s one size smaller kite"s

So confused!

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mattkennedy said..

So confused!

Why?

You live in the tropics don't you?

Just take a look around and see typically what sizes other guys are riding..

Yeah I do . So what you are saying is if the wind is colder the kite size may be smaller. Is this correct

I thought you were confused about what size kite to choose for the tropics.. anyways, now we've digressed

This winter I kited at a tropical lagoon location which is a similar setup to my local spot in Perth (kiting on the lee side of a sand bar). On my first sesh, by looking at the chop on the water (how I help determine which kite to use), I thought I'd be ok on my 8. Rigged it up, went out and had to come straight back in because I was way under powered. Put up my 11, went back out and was perfectly powered...

Lol no mate wasnt confused about kite size. Just all the talk with bigger/smaller size in hotter or cooler temperatures .

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mattkennedy said...
So in the tropics you would go a size bigger than you would normally with the c4??

I am not quite sure what u meant here but the C4 selection I made was a tricky one to decide on I wanted something that could take me in high winds say high 20 knots to low 20 knots I haven't tested it. So I kinder want some cyclone winds this season, lol

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mattkennedy said..

So confused!

It's called density altitude in aviation It only really makes a difference to us if you are in the bottom or top 15% of a kites wind range.
en.wikipedia.org/wiki/Density_altitude
This article may also help
Don't be dense about altitude density
www.planeandpilotmag.com/article/dont-be-dense-about-density-altitude/

I did some maths in a thread a little while back.

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Plummet said..

All other factors being equal the difference in force applied to the kite is 10.8% less on the 35 deg C day compared to the 5 Deg C day.

However the reality is that the <span class="spnSearchHighlight" id="hilite">cold</span> frontal driven wind of wind packs a meaner punch because it is usually more gusty. On a 20 knot day it may gust 25+ knots.

A seabrease driven summer brease is more likely to be closer to a constant 20 knots.

In the formula to calculate force is 1/2 density(of the wind) x velocity (wind speed) squared.

Any variation in the wind speed has a far greater impact in the to the force applied to the kite.

Whats more changes in temperature affect the denisty of the <span class="spnSearchHighlight" id="hilite">air</span>. However when we calculate the <span class="spnSearchHighlight" id="hilite">air</span> denisty using the ideal gas law we use temperature in Kelvin not Deg C. Kelvin starts at -273 Deg C.

So.... To input the 5 Deg into the formula its 273+5. To input 35 deg into the formula its 273+35....... All of a sudden we have only really had a marginal change in temp and therefore very little change to the density of the wind over 30 deg temp change.

Confused?

confused yes, but real world it...

in the "tropics", i can get going like everyone else on a 12 in 15-18kts

in gero i can be jumping on a 12 in 15-18kts

in the tropics i can ride my 14 cat no problem when the wind is strong enough to sand blast my legs

tried that in exmouth and thought i was gonna die, everyone else was on 8's

you can get going no problem with a normal size for wind kite..

but if you want to be powered while everyone is holding lines and baby popping...

go one size up

for the purpose of this exercise, i weighed myself.... 86.5kg

theDoctor just bought himself one month off the pies and the matso ciders

science can bite me

Is sand found in tropics better for sand blasting than the one found in cold climates? Discuss

I put it simple I'm 65kg I mainly use a laluz tt 135. If its blowing 13knots and gusting around 18-19 knots then ill be more then happy to put up my Zephyr. If its under 13 knots I don't bother. If ya happy mowing lawns with a North Nugget between 11 and 13 who's to stop ya.

Broome does seem to get a lot of visitors who think they can put up a 10m kite thinking yep should be right while all the others are playing around on 14,15,17m and only to disappionted.

Say the least, how do I know this? I've don't it lol ha ha

On topic...took the 2014 12m Catalyst out yesterday in 16-21 on the tt. Summary of my impressions in direct comparison to my ol' 2011 11m c4 so far:

- Again felt at home straight away, similar overall feel.

- Biggest difference for me was the height and float when jumping in these winds, far higher and much better float than that of my 11m C4 and not to mention much more accessible. Dont get me wrong you still need to have good technique, just not as critical as on the c4. (i'm not comparing 12 vs 12m here though) Had some very respectable boosts in the low 20s which really surprised me, usually i can't go that big unless it was at the top end of the 11m (mid-high 20s).

- As the 9m, much better drift that the C4s.

- Same direct 'ozone' feel that i love.

- Same great upwind ability

- Very similar turning speed, maybe ever so slightly slower if anything.

- Can't really comment too much on the low end as i was perfectly fine in this range and always able to make ground up wind. At a guess im thinking 14knts or so, but i only had the kite lines set on the middle knots, so maybe more if i shorten them.

more to come once i have had more time on it.

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Plummet said..

I did some maths in a thread a little while back.

Plummet said..

All other factors being equal the difference in force applied to the kite is 10.8% less on the 35 deg C day compared to the 5 Deg C day.

However the reality is that the <span class="spnSearchHighlight" id="hilite">cold</span> frontal driven wind of wind packs a meaner punch because it is usually more gusty. On a 20 knot day it may gust 25+ knots.

A seabrease driven summer brease is more likely to be closer to a constant 20 knots.

In the formula to calculate force is 1/2 density(of the wind) x velocity (wind speed) squared.

Any variation in the wind speed has a far greater impact in the to the force applied to the kite.

Whats more changes in temperature affect the denisty of the <span class="spnSearchHighlight" id="hilite">air</span>. However when we calculate the <span class="spnSearchHighlight" id="hilite">air</span> denisty using the ideal gas law we use temperature in Kelvin not Deg C. Kelvin starts at -273 Deg C.

So.... To input the 5 Deg into the formula its 273+5. To input 35 deg into the formula its 273+35....... All of a sudden we have only really had a marginal change in temp and therefore very little change to the density of the wind over 30 deg temp change.

Confused?

Which just means that it makes a bees dick of difference.
We all kite at sea level, so altitude makes no difference at all. Most of us kite between 15C and 25-30C temps, so the difference is actually more like 5%, and this does not equal a full kite size or 3 as some suggest.
Most people misread the wind in a new location and then begin to believe this total BS about massive differences in power delivery between a cooler location than a warmer one.
Don't be mislead, 20 knots somewhere is basically 20 knots anywhere!!!

Years ago I used to fly ultralight aircraft. The difference in take-off length, rate of climb and glide ratio between flying on a cold winters morning (0 - 8C) and a hot summers day was phenomenal. They said that once the temperature exceeded 40 degrees some planes couldn't even take off.

The hottest I've kited in was 38C, I couldnt really tell if I had any less power than I have in winter.

I reckon it's more the humidity which makes the difference, not the temperature. Moist air versus dry air. By the way I don't think it's a 3m difference (just anecdotal experience where misjudged the right kite size in the tropics), probably only a ~1m difference. One thing I think we can all agree on - it sucks to be under powered

My miscalculation to mix up air density with humidity thinking they are in it together but obviously not. I'm going to say that default has a point lol

@ KP Steve temperture is only part of the equation, humidity is anouther part of the equation than can effect the performance of a wing. If plummets calculations also included typical variations in humidity between places like carins and exmouth you would see it is more like 15%.
Also if 5% is a Bees dick why is it so hard to get in a discount when purchasing equipment.

I think listen to the people who fly everyday in these conditions...regardless of the meteorological calculations, which are at most fun to do, but its the empirical experience that counts most.

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eppo said..

I think listen to the people who fly everyday in these conditions...regardless of the meteorological calculations, which are at most fun to do, but its the empirical experience that counts most.

So who flies every day in conditions that vary by 20-30C?
I do get to travel quite a bit in my job, and in my experience it makes very little difference. Began kiting in Melbourne Vic, have kited at or close to the equator, and in 20 knots in either location would be using the same size kite and approx 24 yrs flying kites and 15 kitesurfing.

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Kitepower Australia said..

eppo said..

I think listen to the people who fly everyday in these conditions...regardless of the meteorological calculations, which are at most fun to do, but its the empirical experience that counts most.

So who flies every day in conditions that vary by 20-30C?
I do get to travel quite a bit in my job, and in my experience it makes very little difference. Began kiting in Melbourne Vic, have kited at or close to the equator, and in 20 knots in either location would be using the same size kite and approx 24 yrs flying kites and 15 kitesurfing.

Well well there you go then....lol

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eppo said..

Kitepower Australia said..

eppo said..

I think listen to the people who fly everyday in these conditions...regardless of the meteorological calculations, which are at most fun to do, but its the empirical experience that counts most.

So who flies every day in conditions that vary by 20-30C?
I do get to travel quite a bit in my job, and in my experience it makes very little difference. Began kiting in Melbourne Vic, have kited at or close to the equator, and in 20 knots in either location would be using the same size kite and approx 24 yrs flying kites and 15 kitesurfing.

Well well there you go then....lol

Hmmm. I have been keeping away from this one because it really needs measurement to settle .

There are a lot of variations to take into account but in my opinion there is a significant difference , having spent significant time and money on the water, using a lot of different gear, over a bloody long time with a lot of different people with different skill levels , in both tropical and southern conditions ....

Just don't accept there is a bees dick in it even if you have sailed all over the world over a million years . Give us a break, show some respect - we also have experience.

Pilots up here report that there is a significant difference in lift both in location and time of the day which they need to take into account in planning their flying . I have flown with them .

I also have seen people on many occasions come up from down south and set up to the wind conditions and fail while we are set up on bigger gear to suit . Many of those people are experienced kiters .

I have traveled from here frequently to southern SE /SA coast and been surprised by the wind power to kite size difference - The difference being roughly 1-3 metres . Its hard to put your finger on a figure and is very subjective . On many occasions I used 10m down south which would have needed 14 here .
If the difference is in fact 10%, that is not an insignificant figure - 1 -2 metres of kite can be the deal breaker between a great day being able to develop apparent wind and crap . 10% of $1m is $100k - is that a bees dick ?

Guys like Puetz will report being blown away by the difference between here and places like Vietnam and Gero in hang time in similar wind conditions . Puetz's years in experience can only be measured by his time not spent on the water.

Its all a bit subjective - but there it is- back to the discussion which I believe was about 2014 Cat , 12 and 9 ?

did my calculations take into account a change in humidity? No they didn't All other factors remained equal. I calculated the change in force relating to a change in temperature.

Does humidity affect the force? yes it does. Water vapour is less dense than dry air. So humid conditions will give you a reduced density and therefore reduced force.

You also have to include the atmospheric pressure aswell!.. .... . . .

Very interested in what you can tell us about the effect of humidy and pressure Plummet

We have humidity in spades. This time of the year ranges from 70-95 % in 33-35 degrees.

Also pressure will be around 1006 -1009. Where I am from - SE /sa it is 1011 to 1014 hpa at this time of year .

If we have cyclonic conditions I believe it gets well below 1000 hpa

Back to the actual subject - who's the best dealer in WA to have a demo/purchase? Couple of us in Geraldton are pretty keen on testing the 12

Try Jason at Westoz kiteboarding, I demo/purchased my 2014 cats from him.