Foiling downwind at 10kts vs 13kts+

[tkaraszewski]

Keelboats are slow, and has highest VMG dead downwind?
Or can they go faster even with a spinnaker when bearing deep?

The problem with heavy keelboats is that they can't plane, and so regardless of how windy it is or what angle they're sailing, they can't go faster than something like 6-8 knots (depending on the boat). If your maximum boat speed is 7 knots, you should sail 7 knots straight downwind for best VMG. Lighter weight boats, like kiteboards, will accelerate to much higher speeds at higher angles.

[Regis-de-giens]

My experience in winds where ultralight freeride foilkite hardly fly, is that :
- if you want to get downwind for a long travel, to get back to shore for example, better to "build your speed" and have speed instead of deep angle, kite stable or very very slow motion

- if you need to punctually go deeper , you can move the kite or loop it, but on big kite you need to be very accurate in piloting it, when kite is rearward, and most of all , you loose so much speed that you may loose planning rapidly, with the risk to loose line tension and put the kite in the water. I only do this loop and punctual kite move if i have an obstacle that forces me to go deeper or just before reaching the shore to stop the session

[alekbelia]

New, better data from yesterday.
Kite Peak5 5 sqm, wind 12-14 knots, 860 front wing, rider 100 kg
On the picture first downwind (green line) was mixed with/without loops. Speed above 20 kmh with some variations. Then I decide to make additional downwinds with/without loops.
Second one (yellow line) was strictly without moving the kite. In the first part I tried to reach good speed (near to 40 kmh on the speed chart), then very carefully tried to go down but loosing speed (less then 20 kmh) and finish.
Third one (blue line) was with loops. Speed was constantly above 20 kmh and I finish this downwind with 24 kmh.
download/file.php?mode=view&id=103321
To see the real wind conditions here is short video clip. My friend is with FS Sonic3 13 sqm, 80-85 kg

[Indulang]

Very insightful discussion. Thanks for all the replies!

[Peter_Frank]

Very insightful discussion. Thanks for all the replies!

True, you can use every little bit of the details to get along - as you can see, it isnt difficult to go downwind in 10 knots at all, when you know how to - but to learn, takes some time.

Only thing where we dont agree is HOW, looping or higher speed kite parked - but not that important, you can use both when you practice, going fast and parked is easy, looping require more kite skill and "board heading" experience so to speak.

Peter

[purdyd]

Look this is not a binary thing. There is a spectrum of what works.

Alekbelia just showed he is faster down wind with a steeper angle looping his kite.

We know racers with big foil kites bear off and keep the kite still.

There is a whole lot of space between those, in kite size, foil speed, and power.

[Peter_Frank]

Exactly

[ieism]

New, better data from yesterday.
Kite Peak5 5 sqm, wind 12-14 knots, 860 front wing, rider 100 kg
On the picture first downwind (green line) was mixed with/without loops. Speed above 20 kmh with some variations. Then I decide to make additional downwinds with/without loops.
Second one (yellow line) was strictly without moving the kite. In the first part I tried to reach good speed (near to 40 kmh on the speed chart), then very carefully tried to go down but loosing speed (less then 20 kmh) and finish.
Third one (blue line) was with loops. Speed was constantly above 20 kmh and I finish this downwind with 24 kmh.
download/file.php?mode=view&id=103321
To see the real wind conditions here is short video clip. My friend is with FS Sonic3 13 sqm, 80-85 kg

Are you riding just one tack completly to one side there? Because thats not at all how I ride downwind with a Peak. I sort of ride carving turns downwind, if the wind is low with downloops. This gives you a speed boost evertime you carve and loop and it;s also a little more fun. So I'm more or less flying figure 8ths and following the kite with carved turns, same as I do in snow upwind sometimes. I can't find a good gps track of it, this was in very light wind I think but you get the idea.

[alekbelia]

Are you riding just one tack completly to one side there? Because thats not at all how I ride downwind with a Peak. I sort of ride carving turns downwind, if the wind is low with downloops. This gives you a speed boost evertime you carve and loop and it;s also a little more fun. So I'm more or less flying figure 8ths and following the kite with carved turns, same as I do in snow upwind sometimes. I can't find a good gps track of it, this was in very light wind I think but you get the idea.

No one tack. Only jibes. A week before I successfully tried tack with foot change on Peak5 6m at wind 7-8 m/s (gusty wind on the same lake). But I prefer to ride with smallest possible kite because I like to play with waves, loops and fast moving of the kite trough the power zone (I'm a racer so I play with Peak's only when I have time to play or in tough conditions (big winds and waves or nobody on the beach to help parking the kite)).