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Post your polar and VMG

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Mossy 757
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Re: Post your polar and VMG

Postby Mossy 757 » Thu Aug 17, 2017 6:40 pm

I'm sorry if you interpreted my comment as a bash on your session, that's not what I meant. I was simply implying that with the power I know the 18m Sonic produces, it looks like you were dragging an anchor!

I guess I'm just a little surprised that your peak velocity never broke 20 knots with that kite.

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Peter_Frank
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Re: Post your polar and VMG

Postby Peter_Frank » Thu Aug 17, 2017 7:20 pm

But it doesnt matter how fast you go, most dont want to go fast, thats for sure, and 20 knots is not fun anymore :(

Your combos alexrider works pretty perfect, the thing about high AR kites for high AR wings, and low for low, is simply bull that some has "invented" for no reason IMO, it simply makes no sense.

The only thing I personally would never do, is ride 17 and 18 m2 kites, as I dont like "racing" style but agility and max lowend so stop around 12 m2, but it is very personal, for jumping and hangtime the big kites are way better of course :rollgrin:

These wings like the Cab with a foil kite is just awesome in marginal winds as you can foil around in tight turns much better, or if you like these kites (they are SO great and beatiful, a really phenomenon in aerodynamics)

You are the first in here to make this really interesting comparison - nobody else has shared, respect, TOTALLY Alex :thumb:

8) PF

evan
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Re: Post your polar and VMG

Postby evan » Thu Aug 17, 2017 9:28 pm

alexrider wrote:
Thu Aug 17, 2017 5:52 pm
- race foil kites excel upwind; downwind, their high aspect ratio is of little help
If you go fast enough, high-performance foilkites go better downwind than any other kite on earth.

Funny to see the DA is impossible to push beyond 16kn, a speed that is very hard to get below on race gear when your upwind speed is around 20-25kn :lol:

Mossy 757
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Re: Post your polar and VMG

Postby Mossy 757 » Thu Aug 17, 2017 10:49 pm

Peter_Frank wrote:
Thu Aug 17, 2017 7:20 pm
But it doesnt matter how fast you go, most dont want to go fast, thats for sure, and 20 knots is not fun anymore :(

Your combos alexrider works pretty perfect, the thing about high AR kites for high AR wings, and low for low, is simply bull that some has "invented" for no reason IMO, it simply makes no sense.

The only thing I personally would never do, is ride 17 and 18 m2 kites, as I dont like "racing" style but agility and max lowend so stop around 12 m2, but it is very personal, for jumping and hangtime the big kites are way better of course :rollgrin:

These wings like the Cab with a foil kite is just awesome in marginal winds as you can foil around in tight turns much better, or if you like these kites (they are SO great and beatiful, a really phenomenon in aerodynamics)

You are the first in here to make this really interesting comparison - nobody else has shared, respect, TOTALLY Alex :thumb:

8) PF
I know you like shitting on my posts just for fun, but do you understand that this is a thread for recording objective performance data? Like, the whole point is to go fast...
evan wrote:
Thu Aug 17, 2017 9:28 pm

If you go fast enough, high-performance foilkites go better downwind than any other kite on earth.

Also, this. Tube kites might be able to go a tad deeper at certain speeds, but nothing gets dead downwind as fast as a foil.

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lovethepirk
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Re: Post your polar and VMG

Postby lovethepirk » Thu Aug 17, 2017 11:32 pm

I apologize if I'm asking in a wrong thread, but I have still not seen a simple explanation of VMG. If I set sail at the shoreline with my buddy walking the beach upshore at the same time to a destination only 1 mile upshore of us. He walks 1 mile upshore in 60 minutes(lazy bastard) at the same time I have made only two simple tacks and meet him at the exact time/place. Is my VMG 1mph although my travel speed while riding was higher?

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alexrider
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Re: Post your polar and VMG

Postby alexrider » Fri Aug 18, 2017 3:31 am

Mossy 757 wrote:
Thu Aug 17, 2017 6:40 pm
I'm sorry if you interpreted my comment as a bash on your session, that's not what I meant. I was simply implying that with the power I know the 18m Sonic produces, it looks like you were dragging an anchor!
I guess I'm just a little surprised that your peak velocity never broke 20 knots with that kite.
Don't be sorry. I know what you meant. I was pulling your leg a bit with my response.
The power of efficient foil kites can be directed not only horizontally for speed, but upwards, and that makes them very good IMO for learning hydrofoil. With a draggy Cab, you can foil almost stopped, and I assure you, it makes the learning process pretty quick and straightforward. At least it did for me.
Even with the Zeeko Freeride, which according to Nico the designer, can reach 30 knots, I've never attempted to go fast; 18 knots max so far. Falling at speed hurts.
The performance I personally appreciate with any given combo, is the best angle to windward and the speed (including VMG) relative to true wind you can squeeze out of it. Going three times the speed of the true wind or close hauling at angles impossible to imagine with a twintip gives me more kick than beating my personal speed record. Or just "being there". I'm an old rider after all.

“You will begin to touch heaven, Jonathan, in the moment that you touch perfect speed. And that isn’t flying a thousand miles an hour, or a million, or flying at the speed of light. Because any number is a limit, and perfection doesn’t have limits. Perfect speed, my son, is being there.”
― Richard Bach, Jonathan Livingston Seagull

Lokihel
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Re: Post your polar and VMG

Postby Lokihel » Fri Aug 18, 2017 5:01 am

lovethepirk wrote:
Thu Aug 17, 2017 11:32 pm
I apologize if I'm asking in a wrong thread, but I have still not seen a simple explanation of VMG. If I set sail at the shoreline with my buddy walking the beach upshore at the same time to a destination only 1 mile upshore of us. He walks 1 mile upshore in 60 minutes(lazy bastard) at the same time I have made only two simple tacks and meet him at the exact time/place. Is my VMG 1mph although my travel speed while riding was higher?

VMG means velocity made good.

You get VMG upwind, VMG downwind, WMG to waypoint etc
It is the vector component of your speed with respect to a given vector.


In simpler terms, VMG upwind is your speed component directly upwind (as in your example, although the number of tacks don't count).
VMG downwind the speed component directly downwind, VMG to waypoint the speed component towards a given waypoint etc

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Peter_Frank
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Re: Post your polar and VMG

Postby Peter_Frank » Fri Aug 18, 2017 6:53 am

Mossy 757 wrote:
Thu Aug 17, 2017 10:49 pm
Peter_Frank wrote:
Thu Aug 17, 2017 7:20 pm
But it doesnt matter how fast you go, most dont want to go fast, thats for sure, and 20 knots is not fun anymore :(

Your combos alexrider works pretty perfect, the thing about high AR kites for high AR wings, and low for low, is simply bull that some has "invented" for no reason IMO, it simply makes no sense.

The only thing I personally would never do, is ride 17 and 18 m2 kites, as I dont like "racing" style but agility and max lowend so stop around 12 m2, but it is very personal, for jumping and hangtime the big kites are way better of course :rollgrin:

These wings like the Cab with a foil kite is just awesome in marginal winds as you can foil around in tight turns much better, or if you like these kites (they are SO great and beatiful, a really phenomenon in aerodynamics)

You are the first in here to make this really interesting comparison - nobody else has shared, respect, TOTALLY Alex :thumb:

8) PF
I know you like shitting on my posts just for fun, but do you understand that this is a thread for recording objective performance data? Like, the whole point is to go fast...

I would never do that (diss anyone for fun) :roll:

Was dead serious in above statements, that most (non racing style riders) would never ride more than 15-20 knots, as even 20 is really fast and for some not fun anymore and on the verge to "too fast" :-?

Just returned to the O.P's post (which was Alex btw), and this thread is not about "to go fast", but to compare and learn from polars and gear.

This is what is really exciting, thus the last post by alex is one of the best I have seen on this forum, comparing two very different kites on an allround hydrofoil (type) used by maybe the majority, THIS is truly interesting objective performance data IMO.

Racing style riders dont care, but many will, and personally I like to see all the aspects and not only one side.

What lacks is of course the same comparison between different kites, using a racefoil, but that might come one day.

Hats off for doing this comparison Alex, most are too lazy to learn or help others by doing such tests, respect :thumb:


So no, it is NOT only about to go fast in this thread (which it also is of course, "look I am faster/point higher than you" and the numbers are always exciting and interesting) - it is about knowledge and understanding of how things work and interact and angles/numbers put into it also :naughty:

At least that was my impression when Alex started this thread :wink:

8) PF

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alexrider
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Re: Post your polar and VMG

Postby alexrider » Fri Aug 18, 2017 7:25 am

lovethepirk wrote:
Thu Aug 17, 2017 11:32 pm
I apologize if I'm asking in a wrong thread, but I have still not seen a simple explanation of VMG. If I set sail at the shoreline with my buddy walking the beach upshore at the same time to a destination only 1 mile upshore of us. He walks 1 mile upshore in 60 minutes(lazy bastard) at the same time I have made only two simple tacks and meet him at the exact time/place. Is my VMG 1mph although my travel speed while riding was higher?
Lokihel's explanation should satisfy you. Here's however a bit more about the polar diagram, in case the VMG plot still confuses you, which is understandable because the VMG vector isn't oriented in the direction of the gain to the wind it represents, but in the direction you're going relative to the wind (unlike the speed polar - the outer line). Hoping the following diagram will clarify the concept, the example showing two different points of sail ( in blue and in green).
2017-08-17_211345cf.JPG
And here an article that will give a full answer to your question:
http://sail.navas.us/why-vmg-matters.html

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alexrider
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Re: Post your polar and VMG

Postby alexrider » Fri Aug 18, 2017 11:11 am

I really appreciate your comments, Peter.
Indeed raw speed isn't the only measure of performance and even less of sheer fun.
As I responded to Mossy earlier, the polar plots give more interesting than just raw speed. The best angle to windward and speed (included VMG) relative to the wind, which are true measures of efficiency, are the parameters you and I seem to be more interested in. They allow, as you say, to compare the performance of differ gear and setups.
Another comparison I'd like to do out of curiosity is to compare best twintup, directional (surf and raceboards) with hydrofoils using the same kite. We know what the results will be, but I like to see it in a polar diagram. :o BTW if I just want to go fast, I'd take my OR Mako, with which I feel very comfortable at 20+ knots. That's the board I use when the tide doesn't allow foiling.
Below, my session yesterday with my brand new Sonic Race 15 (with 17m lines) in 10-12 knots, combined with twintip Magnum Mako (a wider Mako 44cm made in Thailand). A surprisingly good light wind carving combo, btw. I'm impatient to compare with Zeeko HF.
2017-08-17_210255.JPG
Peter_Frank wrote:
Fri Aug 18, 2017 6:53 am
....
I would never do that (diss anyone for fun) :roll:

Was dead serious in above statements, that most (non racing style riders) would never ride more than 15-20 knots, as even 20 is really fast and for some not fun anymore and on the verge to "too fast" :-?

Just returned to the O.P's post (which was Alex btw), and this thread is not about "to go fast", but to compare and learn from polars and gear.

This is what is really exciting, thus the last post by alex is one of the best I have seen on this forum, comparing two very different kites on an allround hydrofoil (type) used by maybe the majority, THIS is truly interesting objective performance data IMO.

Racing style riders dont care, but many will, and personally I like to see all the aspects and not only one side.

What lacks is of course the same comparison between different kites, using a racefoil, but that might come one day.

Hats off for doing this comparison Alex, most are too lazy to learn or help others by doing such tests, respect :thumb:


So no, it is NOT only about to go fast in this thread (which it also is of course, "look I am faster/point higher than you" and the numbers are always exciting and interesting) - it is about knowledge and understanding of how things work and interact and angles/numbers put into it also :naughty:

At least that was my impression when Alex started this thread :wink:

8) PF


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