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I think I answered the topic question
The last 4 tacks on the right (higher wind section) had an mean upwind angle of 31° done in about
15 knts with a Flysurfer Sonic Race 11 m² on 16 m lines and this high AR Monofoil:
http://kiteforum.com/viewtopic.php?f=19 ... 5&start=88

I don't think this is possible with a stabifoil. But for the mono (riding with around 14 knts) it is not the end for sure, as 15 knts wind / 14 riding speed is not a very good rate for upwind angle, if wind is much higher so with a 6 or 7 m² racekite in clean 30 knts without to much waves maybe even up to 25° are possible.

And I also answered for me what all those numbers about performance are worth to talk about:

- with this setup I passed a well known difficult bottleneck, which normaly needs many tacks, this time like nothing with just 3 tacks
- when I first tried boosting I nearly exploded loosing my board by the shock how much it was going upwards
- invented a nice new trick "air tack" transition with a landing far luvwards of the start
- was still able to jump about 4-5 m high when a very experienced friend was no more able to relaunch his foilboarding addicted tubekite ...

Interesting, what about downwind? Are you able to hold some speed?

Peter_Frank wrote: ↑

Tue May 01, 2018 8:20 pm

The angles you guys show above, is that with a foilkite or a tube (low or high AR) ?
Makes quite some difference in my experience.

It has been a known a decade old fact from ice sailing Wissa competition that any tubes nor 'medium' AR foil kites like Flysurfer Speed3 did not have any change against Russian foil kites like Elf and Paraavis. In Russia Flysurfer owners created their own competitions I hear because they wanted to race but 'open' class was impossible. Alpine G skis and high ar kite, that was vmg. Similar glide with skis like hf can offer today.

Elf the brough their high ar foil kites to water race board races and were (almost) unbeatable. That probably made finally Ozone to realize where the race speed is and they developed Chrono and Heineken marketed it to the masses with foilboard in 'SF weekly race'.

(That's how I'd write the history.)

And your experience is IMO correct.

On hf and water I'd also add wing loading to equation. Water is a fluid and I believe you used to be hang glider so you know wing loading and speed polars what airfoil has.

Speed3 was designed to be much more user friendly. Speed2 would have been a much better race kite. Neither is mid AR.

These racers seem to be tacking through at least 45 degrees, gybing even better angles, at least for Parlier. It’s very reminiscent of ice boat racing where each leg is typically one tack or one gybe through similar angles if you call the lay line.
https://m.youtube.com/watch?v=VLLXoKi3hq4

Presumably if the focus is not vmg, you could do higher angles as shown above, although getting into 60 degrees is pretty amazing.

Racers can do that also when going as slow as 14kn boardspeed over water without current. But mostly they do 20-25kn upwind on slightly lower angles which end up in a vmg above 15kn upwind

foilholio wrote: ↑

Thu Aug 30, 2018 12:27 am

Speed3 was designed to be much more user friendly. Speed2 would have been a much better race kite. Neither is mid AR.

That's why I put it on quotes: 'medium' AR foil kites like Flysurfer Speed3. At the time (2010) Speed3 was one of highest aspect available and a race oriented kite. But with today's race kite standard it is 'medium' or even 'low' aspect.

Racers only aim for higher pointing if they have missed the mark just slightly, and can pinch up over, instead of 2 extra tacks that would be slower.

Years ago we saw Nicolas parlier as I remember, going 27-28 degree to the wind

And going even higher is probably possible, but vmg is what everybody wants when racing so not (m)any who seeks to point as high as possible.
Eventhough personally I find it interesting and fascinating as a freerider

You could be right Horst, that you can point even higher with a stabless as less parasitic drag.

But it could also be opposite, that a really small stab, even with its higher overall drag, which will give a smoother more perfect ride especially over long distances, will be beneficial in overall upwind angle and beat the less stable one that requires compensation interactions full time, to try to sit spot on at the best L/D ratio.

Where this "perfect" spot will be much more well defined having a stab.

Just theory of course, but in many similar dilemmas it is like that - adequate control gives better performance even for the very best riders/pilots.

So it is not that easy to answer, and maybe there IS not just one answer

PF

Peter_Frank wrote: ↑

Thu Aug 30, 2018 9:08 am

Racers only aim for higher pointing if they have missed the mark just slightly, and can pinch up over, instead of 2 extra tacks that would be slower.

Years ago we saw Nicolas parlier as I remember, going 27-28 degree to the wind

And going even higher is probably possible, but vmg is what everybody wants when racing so not (m)any who seeks to point as high as possible.
Eventhough personally I find it interesting and fascinating as a freerider

You could be right Horst, that you can point even higher with a stabless as less parasitic drag.

But it could also be opposite, that a really small stab, even with its higher overall drag, which will give a smoother more perfect ride especially over long distances, will be beneficial in overall upwind angle and beat the less stable one that requires compensation interactions full time, to try to sit spot on at the best L/D ratio.

Where this "perfect" spot will be much more well defined having a stab.

Just theory of course, but in many similar dilemmas it is like that - adequate control gives better performance even for the very best riders/pilots.

So it is not that easy to answer, and maybe there IS not just one answer

PF

R1V2 and Mikes Lab Bullet have set the standard for VMG downwind, and pretty much everything being developed right now is trying to meet or exceed that. Upwind is the easy part, it's downwind that seems to make or break the race based on your gear.

Passionating topic. I had actually launched a polemical topic on french forums 2 weeks ago about the pure upwind angle of a medium ratio foilkite vs race foilkites, to challenge the simple idea that a race kite has necessarily a higher upwind angle ... nice reactions of a lot of riders who mixed VMG and upwind angle ... anyway .

So ! Sorry I only read this topic right now and'll have some delayed remarks:
- Sergio mentioned that the speed ratio wind vs rider speed is crucial ; right !!! and we should focus on that point IMO ;
- so, IMO rather than trying to get a higher L/D ratio of the kite or of the HF, focussing on a slow planning HF and a kite that develops lift at low speed is the key to reach the higher angle . Again I do not talk about VMG which is competitors focus, just pure angle whatever the (low) speed.
- a very large HF (and/or a very light rider ) could "win" even if not the best race kite (for a given kite size)

I do not see barriers to do far better angles than above angle figures, but with far bigger/slower HF; Imagine you have a support like a big-beginner sailboard that can hold your weight at 0 speed ; you can put your kite at (almost) 90 degree, with you up on the floating board ; then you add a big deep fin in the center of the board ; if you point the board at 20 degree wrt the wind direction, the fin will remove lateral drift, and you should still go slowly upwind (very close to) 20 degree, no ?

To me the actually physical barrier is only the "cumulated" L/D ratios angles of the kite + the board ; assuming L/D=10 for the kite and same for the board, you can then go upwind up to 12 degrees ...

So we need to look for an enormous Hydrofoil and a grunty kite that delivers power at very low speed (medium ratio) ; a bit provocative, I know ...