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@@mbkiteboarding interesting! In my testing I found that it seldom missed jumps. It could be that you're on an old version of the app with an old algorithm. Best to update the app just in case 😊 the algorithm is constantly being improved
I don’t even kiteboard, but you’ve got my sub brother. I fly stunt kites and it brought me here and I’ve learned so much from your videos that I can apply into multiple formats, thank you.
There were a few minor errors ... I am happy to help with technical explanations anytime. Eg Lift is a square function of velocity, as in your equations. You incorrectly went on to say its 'exponential'... x^2 vs e^x
Great video Mike! This confirms a recent experience I had: I forgot my smaller kite and was out on a 16m switchblade in 20-25knots. I was waaay overpowered, and could barely hold an edge. The only way I was able to jump was by using some fun kicker waves. the hang time was absurd... But I wasn't going very high.
Very nice content. Also interesting to say is the influence in the density of the air. Sometime you go in 30degC on the water, some times in 2degC or in high mountain lakes. The density varies around 20% and therefore the Lift too. Some specialists go on the water and choose a size with their wind measurement, but this can be tricky when you are used to kite in other temperatures. It would be a nice master thesis for a cfd student to really understand the powering up of the kite while you jump. Maybe numerical results bring a benefit on how to get the best performance out of the kite. (Im just jumping 12m - 😅) Thank you for your content! I manage heliloops thanks to your video!
Mike I am a mechanical engineer and my job is helping to design jet engines. I love this video and think the principles you describe are spot on. The numbers for the lift aren't necessarily realistic since you used made up factors of 1 for the lift coefficient and density so no one should take the your lift force values and think they are real, but the relationship between the variables and the trends are absolutely real and they show why you can jump higher on a smaller kite
Thanks Doug! Yes I used made up values partly due to naivety from the physics side and partly because I thought that it wouldn't make a difference to the relationship at the end of the day, since it's only 1 term and they're all first order variables, except for airflow. I'm not sure if I'm right in saying that, but it 'seemed correct' based on what I recall from university (quite some years ago 😅) Does my explanation make sense? Keen to hear your thoughts!
Consistently some of(if not) the best kite content on the net, well done Mike... (we've all got a mate or two who rides a size or two bigger in stronger wins because they think they'll go higher)
Hi Mike great video. Could you make next video with including a riders weight difference as I believe its a very big factor choosing the kite size and type of the kite being 65kg or 95kg rider..
Great video - brilliant discussion starter! Definitely, you can expand the theory bit more: with smaller kite you have more control of CL and V components of your lift equation, which means you can time it with edging to give you the highest jump result: kite position, angle and speed - you can more easily park smaller kite in high winds to get highest initial riding speed and as you redirect the kite to zenith you sheet out which then reduces the drag coefficient of the kite and increases V even further. Then as the kite approaches the zenith you time releasing the edge with sheeting in, the latter changes the shape of the kite bringing the canopy closer to critical angle of attack (ramping the CL component to max) at max kite speed which then maxes your lift equation - and boom you are flying!!! With large kites at high wind speed you simply have no ability to control anything other than keeping above your head and praying. :D
jaja i love your chanel mikey ;p i love the phisics of thing and its vey rare that people talk about it ;p it is like seeing the matrix ;p take care bru ;p
Great video. A lot of misconceptions about the physics out there. Many people dont know why apperent wind exists and how it works. 1 more thing about the topic big kite vs small kite jump height. When u leave the water in a jump - you start to travel downwind. This reduces your apparent wind in your kite -> decreasing lift -> you sink -> land. With super strong wind on a small kite you dont lose this lift as quickly - getting the vertical pull longer. -> jumping higher. Sorry if this explanation isnt good in english. Also if you really want to dig deep into kite physics i recommend the Phd paper of Jan Hummel, he build a kite measuring device for duotone called „ project teta“
Nice one Mike... Who did you call to get those Calculations explained`? While i allready felt something like this is the reason for flying higher in stronger wind, this makes it much more clear.. only thing.. i feel using such smal kites with about 5-6 m² is realy much more dangerous.. not only because you can fall deeper... what we finaly aim for in a controled way, but because such smal kites are much less forgiving with any wrong movment of the bar... you just look at them and they start to loop.. Well with 54 Years. i aim for 15 m at the end.. so 7 meter still to go.. and even this .. my collegues tell me, is totaly crasy... Well.. they have no idea...
Wicked vid , lots of fun to get the brain engaged in thinking about the science behind the sport we love . Just one point , being that the kite "Size" isn't the actual surface area of the canopy but is supposed to reflect the projected area. However also that we know that those projected areas haven't been literal for most brands for many years but rather an indication of where this kite should sit in the lineup of that particular model ,.. IE this kite is a 12m because a 8okg rider would use it in __ to __ Knots > But yeah love the vids man 🤙
I'm 68, have been riding 16 years and I'm 100 kilos. All I do is try to jump as high as possible, and jump transitions. I have had my 12M XR kite in 25k winds (accidentally due to a very abrupt wind gust) as well as my 10M XR kite in the same winds. While I definitely have more power in the kite with the 12M, it is much harder to keep my edge, which gives me more horizontal jumps, less vertical. I could try going to a smaller board, as Toby Braeuer once suggested with the larger kite, but while I would get better edging and more vertical take offs, as well as some very nice hang time, I would not have the kite speed to get the same height as the 10M in the same wind. This past June I went to Floras lake and was boosting vertical 30+ footers every jump (as per multiple witnesses on the beach and video evidence) on my 10M with wind speeds of 25-35mph (approx 21-30kn) off of flat water, no ramps or kickers. Absolutely love the Core XR kites, just wish I had the money to keep updating them. Thanks for all of your great content, keep up the good work. If you ever find yourself coming to the San Francisco area and want to ride an awesome flat water spot, especially in July, contact me.
great video Mike :) do kite brands have hydro simulations when they design their kites? can those be used to find the best lift as a function of conditions?
Yes but I think that simulators can only take us so far. As the simulator on Nasa states, and as my research has shown me, lift can only be approximated for low angles of attack. Once you get to extreme angles, it's a helluvalot more complicated and real-world testing is necessary. By the way! There's a nice video about the modern lift equation on NASA GRC RUclips: ruclips.net/video/wYyry_Slatk/видео.html
Super nice explanation, it will help even beginners understand, why they are not enjoying their sessions overpowered. I have a few additions though, because this at the moment, is only the theoretical part of lift an aerofoil(in this case the kite) could make. But in practice, the power of the kite, as well as the actual lift greatly depends on the weight of the rider. And i’m not saying the lighter the better! I think with good technique for the pop, a heavier rider can edge harder, pop harder therefore he can load the lines better and increase the efficiency of the kite. I know it feels like it’s not really a part of this equasion but to me it feels like it should be just as much as the true wind and induced wind adding up to apparent wind. I mean the lift calculated here is a constant so if all the rest wouldnt really matter in the case of actual jumping, all the jumps would last forever. About the strong wind and big kites: Just another testimonial: i’ve ridden 17m kite in 25kts+ even worse on a door board. It was more trying to survive than actual kiting. People were sending 10+meters next to me on 9-10m kites i could barely go 3-4 meters and it was a fight (obviusly i didn’t chose to take this one, i was teaching a heavy 120kg guy and i took the kite when the wind picked up to make sure he’ll be safe) And there comes the next part about the opposite of the range: when jumping lit on a 5m kite 35+kts i feel like there is a moment my board is generating lift also, or even more often it has huge drag pushing me under the kite, depending on how i put the board. It’s kind of a scary feeling loosing line tension while the kite is still in front of you. Now my question is, surely it is up to the rider to solve this issue, but don’t you think 6m kites in stronger winds will basicly plateau before reaching new high scores, or if it does make people reach 40m, the trend changes and everyone has to size up again to reach new top height?
Once again stellar content mate, I'm always stoked to see a new vid from you! With regards to the density, from what I've felt a low density day in Langebaan (say 1005hPa) feels way lighter than a high density day, and Cape Town is always slightly more dense 1020~hPa. Does this also work similarly to wind speed in that a reading of 1005, while only a small percentage lower than 1020, is actually logarithmic? Should I be checking for this when evaluating the forecast? Would you be interested in doing a follow up video on the lift formula with a section on density? Also can you hit us up with that spreadsheet?
Super interesting breakdown Mike. I do have one additional question that you didn’t cover during the video. Does the red light shining over the bed in the background signify a side-hustle your working on while out injured?
then what's your take on 13.5 and 15m kites. When its blowing 15-18knots of wind, wouldn't you rather go on a 15m then a 12m? I live in Netherlands and just bought a 15m xr LW because we often have winds in the 14-17 knots range. Now im doubting whether i made a mistake and should have gone for a 13.5....
I would approach the problem from an energy exchange point of view: when you take off you have a high kinetic energy: e = 0.5*m*v^2 where v is your airspeed (upwind ground speed + wind speed) as you fly upwards this energy is converted into gravitational potential energy by the kite. larger kites will be more efficient than small kites as the wing loading is lower. call this efficienty term b. once at the peak of the jump most of the kinetic energy will have been converted to gravitational potential energy: e = m*g*h. equating the two terms and solving for height: h = 0.5*b*v^2 / g the v^2 term will have the largest effect on the height, and we feel this intuitively. at high wind speeds the most important factor in a high jump is how fast directly upwind you are traveling when you leave the water (v = upwind speed + wind speed). larger kites make it harder to edge and pop without going downwind, but with all else constant will take you higher, however, smaller kites allow you to edge and pop better with a higher upwind angle.
No, first of all you mess up the kinetic energy of kiter and kite. Air speed is for kite, but it is not significant as a source of kinetic energy but for the maximum lift which can be achieved. Kiter kinetic energy is measured from true speed and it indeed has some relevance to jump height. However the most important thing is to get the kite travel as fast as possible. High driving speed of course helps that. Unfortunately if you go very fast edging and last moment before take off suffer and advantage of high speed is lost. Why do you think bigger kites are more effective because of lower wing loading? It is more like opposite, smaller kite in higher wind operates at higher Re number which makes it more effective. Big kites are not as efficient, they have much lower lift to drag ratio. This is because kiter can only produce certain amount of counter force by edging, and this force is dependent of kiter's strength and technique. For example 18m kite has ca. 2x as much drag as 9m kite but unfortunately you are not capable to produce 2x counter force for it in your harness hook (unless it is very light wind) to reach same L/D ratio. Big kites are also heavy, they have more inertia which makes them slow to accelerate and thus produce less induced wind during last critical moments of edging before take off. It is trivial to notice that if wind is very low big kite can indeed jump higher than small kite. Small kite will always jump higher if you use your edging potential (and there is enough wind to do so). In practice most people don't use very small kites for big air because risks increase so much when they are fully powered
@@bekanav Hi Bekanav, thanks for your detailed response. I would argue that once the rider leaves the water, the only important reference frame is relative to the air, not the ground. So my use of airspeed for the kinetic energy here is the correct term. I agree with your 18m vs 9m comparison argument, however by efficiency I was considering the L/D ratio when the rider is flying upwards from the instant after takeoff, with the bar sheeted in, so I believe the kite would be performing at its target L/D ratio, do you think this is correct? In terms of Reynolds number, I would say that the change between light and high wind riding is not that significant. If Re is calculated as some constant k * squareroot(kite size area) * air speed, it does not change hugely for a 12m in 20kts vs 8m in 30kts. So I wouldn't say the lift/drag ratio for the wing would be drastically different between high and low wind settings. I would estimate that the higher wing loading of a small kite plays a much more significant role in efficiency than this change in Reynolds number, but it's hard to say for sure, what on your thoughts on this? I agree with your comment on larger kites being heavier, additionally using more energy and drag to redirect them upwards before takeoff.
@@maxff123 Main difference is drag is related quite closely to the kite size but lift increases in square to V. So smaller kite has considerable higher L/D ratio if your ability to take F to your harness hook is constant (as it is, or it is not wind dependent). There is also slight advantage to RE number because twice as big kite has 1,4x bigger chord size but smaller kite can easily be used 2x as strong winds. So smaller kite works with higher RE number which means aerodynamic advantage. However basic principle of L increasing in square to V while D is constant is much more significant than RE number. RE is related to object size and airspeed. In practive after take off smaller kite performs at much higher L/D ratio because it has much higher airspeed. Another way to think it is you can't load big kite enough. There is a 160kg guy who can jump almost 50ft with 21m kite, that is because he can make that kite work much higher L/D than anyone normal weight guy can. In practice you can see that kite is not that slow when he uses it - and it is a very slow kite for normal weight person. Yes, in practice kite weight is like drag, not same but quite a lot. Bigger kites, especially foil kites, are relatively even worse for their weight because kite volume increases faster than kite area. Now I see your point of kinetic energy. However it must be measured from the ground speed when kiter travels on water and it certainly can't change drastically after take off - like it would do if then measured from the air speed. Just getting airborne can't increase your kinetic energy. After take off kinetic energy of kiter starts to convert to potential energy. However kite pumps more energy to the system from the wind. This happens as long as kite climbs higher and has more lift than kiter weights. Because it is possible to jump just moving the kite, so having 0 kinetic energy, I don't see that way of thinking very practical. Jumping is mostly about kite speed and ability to take high force from the kite - which makes kite go fast and develop a lot of lift.
Hi thx for your videos, super useful. I'm 95kg for 192cm tall. I often use a 14m orbit to try to get higher. I'm able to ride with it in 20/22 knots with flat water and my record is 8.4m. For you is the right size of kite or I should use a smaller kite, to improve the lift? Or for my weight is the maximum height that i could achieve? 🤙🏼
Nice video Mike. Really interesting. Just a doubt for me. You said, and I agree with you, that by sending the kite quickly to te zenith u will get more lift/pull but what about the fact that we should expect the kite to go up but more deep in wind window so pulling us little bit more forward than up?
You are great, Mike. I appreciate very much your explaination style, your clear and fact based output and the posotive energy you are able to transfer through these Videos! Kudos. And I will check out the shop...
Great vid as always. A good companion vid would be some sort of jumping "benchmark", breaking down kite size vs. wind speed and target jump height for those of us not fortunate enough to live in strong wind areas so we know if the issue is technique or wind speed. For example, what jump height would be an indicator of good technique in 15kts with a (say) 13.5m. I'd think the 15-25kts range would be most interesting.
You'd have to ask him, haha :) I'm not saying he was wrong to do so. I'm pretty sure he was on a Dice, which has more surface area in the wingtips and less projected area - thus it produces less lift per square meter of canopy. A 9m Dice has similar lift to an 8m Evo or Rebel. A Dice certainly wouldn't be my choice of kite for trying to jump as high as possible.
Hey Mike, thank you for the good explanation. I`m missing the density in the lift calculation. Kiting on a lake at 5400 feet will certainly generate less lift for the same kite size and wind speed.
Yes I intentionally didn't get change the density. I wanted to keep all else constant for the sake of comparing apples with apples. Ceteris paribus, as the saying goes :)
Excellent vid, love the physics... & first time I've seen air density mentioned in over 20+yrs of kiting.... it's noteable! Don't just look at the wind meters... 😉 the weather matters.
You definitely don't hold your edge until kite reaches zenith. Take off happens much earlier than that. If you have a kite straight above you you don't have any grip to the water. The lower you take off the more horizontal grip (edging) you can have. Kite has also more room to climb up to the zenith. During this climbing you get your height.
100% I think the biggest fault in someone's progressions is going out on too big of a kite especially when your a beginner and you see everyone else on 12m kites doesn't mean it's the right size. I know i was a victim of that but now I'd rather always be on a smaller size kite so I can progress and try new things instead of being overpowered
Good video breaking down the math I always saw it as small kites pop up further with stronger wind but don't land as soft and go down wind but not as much as big kites. big kites only pop up so far till they just catch the wind getting good hangtime and soft landings but take you way down wind. Big kites cover a much larger area from poping out of the water to landing as small kites get more vertical height. Was a good video and yea 60 knots of wing is no joke lol
not sure if most of the people are able to understand this, but for sure it’s fucking great informational vid, I already learned this by reading aerodynamic theory, but finally somebody adopted it for kite.
Yes this video is completely right. The problem with super strong winds and 5m-6m kites is that wind is mostly not steady in super strong +35 conditions. Due to large variations in windgusts, as kite surface and wind speed forces are Squared, it means in lulls on small kites you also drop you like a rock or may have inconsistencies in jumps. ,Also the steering and sweetspot for the bar may become more sensitive to find an small kites. One point to add, the Angle of attack is also very important ingredient for jumping, with a kite flying maximum forward in the wind wind, you can hold the edge better (or fly bigger kite) also explosive high jumping is more easywhern kite flies far forward. (there is a bigger difference in power/depower at the bar) So for best jumping you need a kite almost overflying you, however due to apparent wind and kite drag when kiting, during kiting kite it is stable. So move the Bridle settings inward at the LE. As a bonus the turn is faster/more pivot, which also helps climbing above head faster, at costs of bit added bar pressure during steering.
Can you explain what overflying means? For example if I'm already flying the kite at 2 or 10 o'clock... which is deep in the power zone. What happens to the kite if it overflys me?
@@jondeur2686 If you stand at the beach with kite straight above head, it sits at the edge. In a gust, then lull a kite can overfly you. (very dangerous) Therefore small size kites often manufactured to sit slightly deeper in the window for more stability. However for highest jumping a kite flying to edge jumps higher, indeed lighter material kites, have better drift less overflying. Also the pros never put kites overhead and pull the bar into prevent. All modern kites fly closer to the edge, it is one of the reasons why we jump much higher now a days.
Great video and the scientific data just confirms what we know after some years of trying to maximize jumps. I live in a spot where we have nice thermals but we never get more than 25 knots and have been trying to find what is the max height possible with that and on which size kite, given we have no flat water but nice kickers from the beach. Also line length plays a role in how fast you can throw your kite too.. I tried a 12 evo sls on short lines and got a great boost in mediocre wind as it moved really fast, even though the line length made the kite seem very wimpy at most times..
That would make it easier to hold the edge, but it would also relatively reduce the apparent wind, as the kite would a) have slightly less wind due to the gradient effect and b) reduce the run-way that it has to reach its top speed. At least that's the way I view it. As always, there are pros and cons to both sides of any adjustment. The balance/optimum is often some happy medium. With lines, I find that 22m are the balance point on small kites, for example. You could take longer lines, to allow the kite more run way and thus allow it to reach a higher speed, but you would struggle to hold your edge for the duration of time required - at least, I certainly do.
Hey Mike! Great explanation. Whilst the formula and method works partly. The amounts of Newton force you describe are totally out of sync with reality. No one will ever be that tough to keep up with 8000(N) or so.. Lets say your avg weight is 75kg, 1kg = 9.8(N) = 75 x 9.8 = 735(N) to make you float weightless. If your kites generates factor 10x of your own weight you will be dragged down wind or you cant simply hold your edge, they will shoot you to the moon. I think your formula requires some adjustments to get real world Newtons.
Thanks BD! I actually didn't think of lift in Newtons, but that makes total sense 😂 shows that I never attended a physics class! (well, not any significant ones) Yes I used made up values partly due to naivety of the physics side and partly because I thought that it wouldn't make a difference to the relationship at the end of the day, since it's only 1 term and they're all first order variables, except for airflow. I'm not sure if I'm right in saying that, but it 'seemed correct' based on what I recall from university (quite some years ago 😅) Does the relationship still make sense with these made up values? 🙃
Hey BD! What you're saying is true. One will never be able to keep up with 8000 N. The thing is that Mike's results are not in Newton. For them to be that, he should've used SI units. The SI unit for wind speed is m/s, not knots. Also, the made-up numbers are not ideal to get realistic results. However, it does beautifully illustrate Mike's point :)
Great video , as always ! Mike , what board size would you recommend for me, being 1.70mt tall , practicing big air/old school on 25knots average. What would be the ideal board size ?
Good content dude👊🏽 love the way you are approaching big air kiting as a science! There should be a master degree of kiting maybe🤔 I think it is also good to name that the “R” (air-density) component depends on air the air temperature, humidity and air pressure. So if you jump in places like the Caribbean the same 25 kts of wind will give you less lift then 25 kts of the cold wind in South Africa or the Netherlands for example! So if you want to break records, you should also optimize the air density.
Thanks so much dude! Aaaah yes I totally should have mentioned something about air density in the main takeaways! I didn't want to go too much into detail because I thought it was quite a lot of info already :)
@@gethighwithmike yeah, you’re right! Still good vid dude👊🏽 Maybe an idea for the next video; find the spot with the best density. I think it will be South Africa or somewhere in the North. Keep up the good work, njeeew!
Excellent video. You're pretty good at this teaching stuff for such a foul mouthed f*****. Ha! How do you fit this video in with your previous video "Use a bigger kite"? We were just in Flecheiras on a tour with Andy from Windtown. Brazil is wonderful!! Please hurry up with that edging video!
Haha thanks Jon! If you watch my 'You should ride bigger kites' video again, you'll see that I'm not suggesting riding the biggest kite possible in nuking winds. I'm actually encouraging people to get out in light wind on bigger kites because there are some massive benefits! Lighter wind = lower consequences. More practice = more progress. etc. :) I hope this clears things up! I've heard people misunderstanding this one before haha Edging video will come in about a week if we're fast! :D Maybe 2. Depends on when we run the BAKL CT comp!
Unfortunately not hey! Customs there is such a mission. But I do have 3 of my own kites left there for sale. 8, 12 XR7 and 13.5 XR6. All in excellent condition. You can shoot me an email if interested! 🙃
@@gethighwithmike ok so hypothetical question… hydrofoils sail upwind super fast, like the angle that you can drive the board and generate speed against the wind is far greater than that you can with a tt. Could you theoretically generate more lift with a hf by getting more airflow over the sail due to the higher speed into the wind?
Great video, loved how you explained the formula and of course always like the video inserts. What got stuck in my head, that v^2 is not exponential growth. It's close to it, 2^v would be exponential. Sorry for being a maths teacher. :) But as said, so much maths in a kite video warms my heart. Well done, Mike.
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Mikeyyy, Please make video about edging 🙏🙏🙏🙏🙏 neoowwwww
@@piotrekjaworski8626 You got it bruuu!
Dont like the wetsuitmode, ignores most of my jumps 😩
@@mbkiteboarding interesting! In my testing I found that it seldom missed jumps. It could be that you're on an old version of the app with an old algorithm. Best to update the app just in case 😊 the algorithm is constantly being improved
I don’t even kiteboard, but you’ve got my sub brother. I fly stunt kites and it brought me here and I’ve learned so much from your videos that I can apply into multiple formats, thank you.
Ah wow that's such sick feedback! :D Thanks Shane!
There were a few minor errors ... I am happy to help with technical explanations anytime. Eg Lift is a square function of velocity, as in your equations. You incorrectly went on to say its 'exponential'... x^2 vs e^x
Aah yes makes sense! Thanks for pointing that out 🙏
Great video Mike! This confirms a recent experience I had: I forgot my smaller kite and was out on a 16m switchblade in 20-25knots. I was waaay overpowered, and could barely hold an edge. The only way I was able to jump was by using some fun kicker waves. the hang time was absurd... But I wasn't going very high.
Very nice content. Also interesting to say is the influence in the density of the air. Sometime you go in 30degC on the water, some times in 2degC or in high mountain lakes. The density varies around 20% and therefore the Lift too.
Some specialists go on the water and choose a size with their wind measurement, but this can be tricky when you are used to kite in other temperatures.
It would be a nice master thesis for a cfd student to really understand the powering up of the kite while you jump. Maybe numerical results bring a benefit on how to get the best performance out of the kite.
(Im just jumping 12m - 😅)
Thank you for your content! I manage heliloops thanks to your video!
Mike
I am a mechanical engineer and my job is helping to design jet engines. I love this video and think the principles you describe are spot on. The numbers for the lift aren't necessarily realistic since you used made up factors of 1 for the lift coefficient and density so no one should take the your lift force values and think they are real, but the relationship between the variables and the trends are absolutely real and they show why you can jump higher on a smaller kite
Thanks Doug!
Yes I used made up values partly due to naivety from the physics side and partly because I thought that it wouldn't make a difference to the relationship at the end of the day, since it's only 1 term and they're all first order variables, except for airflow.
I'm not sure if I'm right in saying that, but it 'seemed correct' based on what I recall from university (quite some years ago 😅)
Does my explanation make sense? Keen to hear your thoughts!
Consistently some of(if not) the best kite content on the net, well done Mike... (we've all got a mate or two who rides a size or two bigger in stronger wins because they think they'll go higher)
Aaah thank you so much Jason! Really kind of you to say
They can be training their edging hability :p
Hi Mike great video. Could you make next video with including a riders weight difference as I believe its a very big factor choosing the kite size and type of the kite being 65kg or 95kg rider..
Great video - brilliant discussion starter! Definitely, you can expand the theory bit more: with smaller kite you have more control of CL and V components of your lift equation, which means you can time it with edging to give you the highest jump result: kite position, angle and speed - you can more easily park smaller kite in high winds to get highest initial riding speed and as you redirect the kite to zenith you sheet out which then reduces the drag coefficient of the kite and increases V even further. Then as the kite approaches the zenith you time releasing the edge with sheeting in, the latter changes the shape of the kite bringing the canopy closer to critical angle of attack (ramping the CL component to max) at max kite speed which then maxes your lift equation - and boom you are flying!!! With large kites at high wind speed you simply have no ability to control anything other than keeping above your head and praying. :D
This comment wins
jaja i love your chanel mikey ;p i love the phisics of thing and its vey rare that people talk about it ;p it is like seeing the matrix ;p take care bru ;p
Thank you bro 😁🙌
Yo Mike I downloaded your PDFs. SICK!
Thanks Mike! Stoked you like them!
Great video. A lot of misconceptions about the physics out there. Many people dont know why apperent wind exists and how it works.
1 more thing about the topic big kite vs small kite jump height.
When u leave the water in a jump - you start to travel downwind. This reduces your apparent wind in your kite -> decreasing lift -> you sink -> land. With super strong wind on a small kite you dont lose this lift as quickly - getting the vertical pull longer. -> jumping higher.
Sorry if this explanation isnt good in english.
Also if you really want to dig deep into kite physics i recommend the Phd paper of Jan Hummel, he build a kite measuring device for duotone called „ project teta“
Nice one Mike...
Who did you call to get those Calculations explained`? While i allready felt something like this is the reason for flying higher in stronger wind, this makes it much more clear..
only thing.. i feel using such smal kites with about 5-6 m² is realy much more dangerous.. not only because you can fall deeper... what we finaly aim for in a controled way, but because such smal kites are much less forgiving with any wrong movment of the bar... you just look at them and they start to loop..
Well with 54 Years. i aim for 15 m at the end.. so 7 meter still to go.. and even this .. my collegues tell me, is totaly crasy...
Well.. they have no idea...
GET HIGH With Surfr 🤙🏻
Wicked vid , lots of fun to get the brain engaged in thinking about the science behind the sport we love .
Just one point , being that the kite "Size" isn't the actual surface area of the canopy but is supposed to reflect the projected area. However also that we know that those projected areas haven't been literal for most brands for many years but rather an indication of where this kite should sit in the lineup of that particular model ,.. IE this kite is a 12m because a 8okg rider would use it in __ to __ Knots >
But yeah love the vids man 🤙
I injured too bro. Great vid. Make a Tshirt with the lift formula and some
one going massive
Really deeply explained 👏👏👏 Keep going bro 😎
I'm 68, have been riding 16 years and I'm 100 kilos. All I do is try to jump as high as possible, and jump transitions. I have had my 12M XR kite in 25k winds (accidentally due to a very abrupt wind gust) as well as my 10M XR kite in the same winds. While I definitely have more power in the kite with the 12M, it is much harder to keep my edge, which gives me more horizontal jumps, less vertical. I could try going to a smaller board, as Toby Braeuer once suggested with the larger kite, but while I would get better edging and more vertical take offs, as well as some very nice hang time, I would not have the kite speed to get the same height as the 10M in the same wind. This past June I went to Floras lake and was boosting vertical 30+ footers every jump (as per multiple witnesses on the beach and video evidence) on my 10M with wind speeds of 25-35mph (approx 21-30kn) off of flat water, no ramps or kickers. Absolutely love the Core XR kites, just wish I had the money to keep updating them. Thanks for all of your great content, keep up the good work. If you ever find yourself coming to the San Francisco area and want to ride an awesome flat water spot, especially in July, contact me.
Gold Content! Thanks Bro!
Nice work ! Very high value content here 💯 See you a next time in Leucate 🚀
great video Mike :) do kite brands have hydro simulations when they design their kites? can those be used to find the best lift as a function of conditions?
Yes they do, called look up wing cfd. For example the best wing design for racing would be where you have the highest lift to drag ratio
Yes but I think that simulators can only take us so far. As the simulator on Nasa states, and as my research has shown me, lift can only be approximated for low angles of attack. Once you get to extreme angles, it's a helluvalot more complicated and real-world testing is necessary.
By the way! There's a nice video about the modern lift equation on NASA GRC RUclips: ruclips.net/video/wYyry_Slatk/видео.html
Super nice explanation, it will help even beginners understand, why they are not enjoying their sessions overpowered.
I have a few additions though, because this at the moment, is only the theoretical part of lift an aerofoil(in this case the kite) could make. But in practice, the power of the kite, as well as the actual lift greatly depends on the weight of the rider. And i’m not saying the lighter the better! I think with good technique for the pop, a heavier rider can edge harder, pop harder therefore he can load the lines better and increase the efficiency of the kite. I know it feels like it’s not really a part of this equasion but to me it feels like it should be just as much as the true wind and induced wind adding up to apparent wind.
I mean the lift calculated here is a constant so if all the rest wouldnt really matter in the case of actual jumping, all the jumps would last forever.
About the strong wind and big kites:
Just another testimonial: i’ve ridden 17m kite in 25kts+ even worse on a door board. It was more trying to survive than actual kiting. People were sending 10+meters next to me on 9-10m kites i could barely go 3-4 meters and it was a fight (obviusly i didn’t chose to take this one, i was teaching a heavy 120kg guy and i took the kite when the wind picked up to make sure he’ll be safe)
And there comes the next part about the opposite of the range: when jumping lit on a 5m kite 35+kts i feel like there is a moment my board is generating lift also, or even more often it has huge drag pushing me under the kite, depending on how i put the board. It’s kind of a scary feeling loosing line tension while the kite is still in front of you.
Now my question is, surely it is up to the rider to solve this issue, but don’t you think 6m kites in stronger winds will basicly plateau before reaching new high scores, or if it does make people reach 40m, the trend changes and everyone has to size up again to reach new top height?
02:34 *quadratic
But its a common mistake that people say "exponential" as soon as something is strictly monoton and strictly convex...
Thanks, you're totally right! I'm so out of practice with maths 😂
Once again stellar content mate, I'm always stoked to see a new vid from you!
With regards to the density, from what I've felt a low density day in Langebaan (say 1005hPa) feels way lighter than a high density day, and Cape Town is always slightly more dense 1020~hPa. Does this also work similarly to wind speed in that a reading of 1005, while only a small percentage lower than 1020, is actually logarithmic? Should I be checking for this when evaluating the forecast? Would you be interested in doing a follow up video on the lift formula with a section on density?
Also can you hit us up with that spreadsheet?
Super interesting breakdown Mike. I do have one additional question that you didn’t cover during the video. Does the red light shining over the bed in the background signify a side-hustle your working on while out injured?
The passion lamp 😂😂😂 Ah crap I forgot to turn that off!
@@gethighwithmike 😂😂🤙🤙
then what's your take on 13.5 and 15m kites. When its blowing 15-18knots of wind, wouldn't you rather go on a 15m then a 12m? I live in Netherlands and just bought a 15m xr LW because we often have winds in the 14-17 knots range. Now im doubting whether i made a mistake and should have gone for a 13.5....
Dope video mate 🔥
Thanks bro!
I would approach the problem from an energy exchange point of view:
when you take off you have a high kinetic energy: e = 0.5*m*v^2 where v is your airspeed (upwind ground speed + wind speed)
as you fly upwards this energy is converted into gravitational potential energy by the kite.
larger kites will be more efficient than small kites as the wing loading is lower. call this efficienty term b.
once at the peak of the jump most of the kinetic energy will have been converted to gravitational potential energy: e = m*g*h.
equating the two terms and solving for height: h = 0.5*b*v^2 / g
the v^2 term will have the largest effect on the height, and we feel this intuitively.
at high wind speeds the most important factor in a high jump is how fast directly upwind you are traveling when you leave the water (v = upwind speed + wind speed).
larger kites make it harder to edge and pop without going downwind, but with all else constant will take you higher, however,
smaller kites allow you to edge and pop better with a higher upwind angle.
No, first of all you mess up the kinetic energy of kiter and kite. Air speed is for kite, but it is not significant as a source of kinetic energy but for the maximum lift which can be achieved. Kiter kinetic energy is measured from true speed and it indeed has some relevance to jump height. However the most important thing is to get the kite travel as fast as possible. High driving speed of course helps that.
Unfortunately if you go very fast edging and last moment before take off suffer and advantage of high speed is lost.
Why do you think bigger kites are more effective because of lower wing loading? It is more like opposite, smaller kite in higher wind operates at higher Re number which makes it more effective.
Big kites are not as efficient, they have much lower lift to drag ratio. This is because kiter can only produce certain amount of counter force by edging, and this force is dependent of kiter's strength and technique.
For example 18m kite has ca. 2x as much drag as 9m kite but unfortunately you are not capable to produce 2x counter force for it in your harness hook (unless it is very light wind) to reach same L/D ratio.
Big kites are also heavy, they have more inertia which makes them slow to accelerate and thus produce less induced wind during last critical moments of edging before take off.
It is trivial to notice that if wind is very low big kite can indeed jump higher than small kite.
Small kite will always jump higher if you use your edging potential (and there is enough wind to do so). In practice most people don't use very small kites for big air because risks increase so much when they are fully powered
@@bekanav Hi Bekanav, thanks for your detailed response.
I would argue that once the rider leaves the water, the only important reference frame is relative to the air, not the ground. So my use of airspeed for the kinetic energy here is the correct term.
I agree with your 18m vs 9m comparison argument, however by efficiency I was considering the L/D ratio when the rider is flying upwards from the instant after takeoff, with the bar sheeted in, so I believe the kite would be performing at its target L/D ratio, do you think this is correct?
In terms of Reynolds number, I would say that the change between light and high wind riding is not that significant. If Re is calculated as some constant k * squareroot(kite size area) * air speed, it does not change hugely for a 12m in 20kts vs 8m in 30kts. So I wouldn't say the lift/drag ratio for the wing would be drastically different between high and low wind settings.
I would estimate that the higher wing loading of a small kite plays a much more significant role in efficiency than this change in Reynolds number, but it's hard to say for sure, what on your thoughts on this?
I agree with your comment on larger kites being heavier, additionally using more energy and drag to redirect them upwards before takeoff.
@@maxff123 Main difference is drag is related quite closely to the kite size but lift increases in square to V. So smaller kite has considerable higher L/D ratio if your ability to take F to your harness hook is constant (as it is, or it is not wind dependent).
There is also slight advantage to RE number because twice as big kite has 1,4x bigger chord size but smaller kite can easily be used 2x as strong winds. So smaller kite works with higher RE number which means aerodynamic advantage.
However basic principle of L increasing in square to V while D is constant is much more significant than RE number. RE is related to object size and airspeed.
In practive after take off smaller kite performs at much higher L/D ratio because it has much higher airspeed. Another way to think it is you can't load big kite enough. There is a 160kg guy who can jump almost 50ft with 21m kite, that is because he can make that kite work much higher L/D than anyone normal weight guy can. In practice you can see that kite is not that slow when he uses it - and it is a very slow kite for normal weight person.
Yes, in practice kite weight is like drag, not same but quite a lot. Bigger kites, especially foil kites, are relatively even worse for their weight because kite volume increases faster than kite area.
Now I see your point of kinetic energy. However it must be measured from the ground speed when kiter travels on water and it certainly can't change drastically after take off - like it would do if then measured from the air speed. Just getting airborne can't increase your kinetic energy.
After take off kinetic energy of kiter starts to convert to potential energy. However kite pumps more energy to the system from the wind. This happens as long as kite climbs higher and has more lift than kiter weights.
Because it is possible to jump just moving the kite, so having 0 kinetic energy, I don't see that way of thinking very practical. Jumping is mostly about kite speed and ability to take high force from the kite - which makes kite go fast and develop a lot of lift.
@@bekanav Really interesting thanks, this has changed the way I view the physics involved
@@maxff123 You're welcome. Actually how jumping happens in kite boarding is quite complex and certainly worth of some thought
😋🤙
You think we’ll see a 40m jump on a 6m kite? Also keen for this edging video!
Great video Mike, thank you. Great to get some real physics theory behind this amazing sport.
Hi thx for your videos, super useful. I'm 95kg for 192cm tall. I often use a 14m orbit to try to get higher. I'm able to ride with it in 20/22 knots with flat water and my record is 8.4m. For you is the right size of kite or I should use a smaller kite, to improve the lift? Or for my weight is the maximum height that i could achieve?
🤙🏼
Nice video Mike. Really interesting. Just a doubt for me. You said, and I agree with you, that by sending the kite quickly to te zenith u will get more lift/pull but what about the fact that we should expect the kite to go up but more deep in wind window so pulling us little bit more forward than up?
Killing it brother wishing you the best!
Are those resulting units in newton? So to know if will lift your weight is it "(body weight in kg * 9.8) - Lift formula result" should be > 0?
Nice 👌🏼 video bru!!! Hands down one of the best kite videos Iv ever watched.
Mike, how fast you should send the kite from 30 degrees to zenit? I have experience if you send it too fast it pulls forward instead of up. Thanks
I wish I was living in Cape Town or Tarifa. Great content Mike. Can not argue on your info.
Thank you Mike, well explained, and interesting 😎
Waiting for the edging Video!
You are great, Mike. I appreciate very much your explaination style, your clear and fact based output and the posotive energy you are able to transfer through these Videos! Kudos. And I will check out the shop...
Thank you so much! I really appreciate it! :)
Yo Mike 🤙🏻what cit settings do you have on the cores for boosting big? Cheers 👍🏻
I ride the standard out of the box CIT settings 😁
Great vid as always. A good companion vid would be some sort of jumping "benchmark", breaking down kite size vs. wind speed and target jump height for those of us not fortunate enough to live in strong wind areas so we know if the issue is technique or wind speed. For example, what jump height would be an indicator of good technique in 15kts with a (say) 13.5m. I'd think the 15-25kts range would be most interesting.
Agree! @GethighwithMike Please do this. It would be so good!
Why did Aaron Hadlow use a 9m for his 34.4m jump after Cold Hawaii ?
You'd have to ask him, haha :) I'm not saying he was wrong to do so. I'm pretty sure he was on a Dice, which has more surface area in the wingtips and less projected area - thus it produces less lift per square meter of canopy. A 9m Dice has similar lift to an 8m Evo or Rebel. A Dice certainly wouldn't be my choice of kite for trying to jump as high as possible.
Hey Mike, thank you for the good explanation. I`m missing the density in the lift calculation. Kiting on a lake at 5400 feet will certainly generate less lift for the same kite size and wind speed.
Yes I intentionally didn't get change the density. I wanted to keep all else constant for the sake of comparing apples with apples. Ceteris paribus, as the saying goes :)
Eres, el puto amo!!! gracias crack!!!!
Excellent vid, love the physics... & first time I've seen air density mentioned in over 20+yrs of kiting.... it's noteable! Don't just look at the wind meters... 😉 the weather matters.
Thanks for watching Eric! :D
Got hit by a 35kt squall on a 20m once...ZERO FUN factor ! But massive hang time ,was grateful to be alive 🙏
Great video as usual dude! However....
I promise you - it WAS - 60 knots...... 😐
Cut the crap , buy Core kite and you will get there.
Really nice one, thanks for sharing! Bigup!
Thank you! 😁
Great analysis Mike!! I love your videos, they help me progress. Keep the hat on! 😂
You definitely don't hold your edge until kite reaches zenith. Take off happens much earlier than that. If you have a kite straight above you you don't have any grip to the water.
The lower you take off the more horizontal grip (edging) you can have. Kite has also more room to climb up to the zenith. During this climbing you get your height.
Rewatch it and I can not find the edgeing video?
Great stuff! What is zenith?
100% I think the biggest fault in someone's progressions is going out on too big of a kite especially when your a beginner and you see everyone else on 12m kites doesn't mean it's the right size. I know i was a victim of that but now I'd rather always be on a smaller size kite so I can progress and try new things instead of being overpowered
Good video breaking down the math I always saw it as small kites pop up further with stronger wind but don't land as soft and go down wind but not as much as big kites. big kites only pop up so far till they just catch the wind getting good hangtime and soft landings but take you way down wind. Big kites cover a much larger area from poping out of the water to landing as small kites get more vertical height. Was a good video and yea 60 knots of wing is no joke lol
not sure if most of the people are able to understand this, but for sure it’s fucking great informational vid, I already learned this by reading aerodynamic theory, but finally somebody adopted it for kite.
Yes this video is completely right. The problem with super strong winds and 5m-6m kites is that wind is mostly not steady in super strong +35 conditions. Due to large variations in windgusts, as kite surface and wind speed forces are Squared, it means in lulls on small kites you also drop you like a rock or may have inconsistencies in jumps. ,Also the steering and sweetspot for the bar may become more sensitive to find an small kites. One point to add, the Angle of attack is also very important ingredient for jumping, with a kite flying maximum forward in the wind wind, you can hold the edge better (or fly bigger kite) also explosive high jumping is more easywhern kite flies far forward. (there is a bigger difference in power/depower at the bar)
So for best jumping you need a kite almost overflying you, however due to apparent wind and kite drag when kiting, during kiting kite it is stable. So move the Bridle settings inward at the LE. As a bonus the turn is faster/more pivot, which also helps climbing above head faster, at costs of bit added bar pressure during steering.
Can you explain what overflying means? For example if I'm already flying the kite at 2 or 10 o'clock... which is deep in the power zone. What happens to the kite if it overflys me?
Yep no such thing as steay non gusty thermal wind at 60 mph
@@jondeur2686 If you stand at the beach with kite straight above head, it sits at the edge. In a gust, then lull a kite can overfly you. (very dangerous) Therefore small size kites often manufactured to sit slightly deeper in the window for more stability. However for highest jumping a kite flying to edge jumps higher, indeed lighter material kites, have better drift less overflying. Also the pros never put kites overhead and pull the bar into prevent. All modern kites fly closer to the edge, it is one of the reasons why we jump much higher now a days.
Great video and the scientific data just confirms what we know after some years of trying to maximize jumps. I live in a spot where we have nice thermals but we never get more than 25 knots and have been trying to find what is the max height possible with that and on which size kite, given we have no flat water but nice kickers from the beach. Also line length plays a role in how fast you can throw your kite too.. I tried a 12 evo sls on short lines and got a great boost in mediocre wind as it moved really fast, even though the line length made the kite seem very wimpy at most times..
What about a big kite on shorter lines?
That would make it easier to hold the edge, but it would also relatively reduce the apparent wind, as the kite would a) have slightly less wind due to the gradient effect and b) reduce the run-way that it has to reach its top speed. At least that's the way I view it.
As always, there are pros and cons to both sides of any adjustment. The balance/optimum is often some happy medium. With lines, I find that 22m are the balance point on small kites, for example. You could take longer lines, to allow the kite more run way and thus allow it to reach a higher speed, but you would struggle to hold your edge for the duration of time required - at least, I certainly do.
Why is Ray wearing a Bridgeboosters tshirt ? :)
Thank you for being so clever and making these videos.
Hey Mike! Great explanation. Whilst the formula and method works partly. The amounts of Newton force you describe are totally out of sync with reality. No one will ever be that tough to keep up with 8000(N) or so..
Lets say your avg weight is 75kg, 1kg = 9.8(N) = 75 x 9.8 = 735(N) to make you float weightless. If your kites generates factor 10x of your own weight you will be dragged down wind or you cant simply hold your edge, they will shoot you to the moon.
I think your formula requires some adjustments to get real world Newtons.
Thanks BD! I actually didn't think of lift in Newtons, but that makes total sense 😂 shows that I never attended a physics class! (well, not any significant ones)
Yes I used made up values partly due to naivety of the physics side and partly because I thought that it wouldn't make a difference to the relationship at the end of the day, since it's only 1 term and they're all first order variables, except for airflow.
I'm not sure if I'm right in saying that, but it 'seemed correct' based on what I recall from university (quite some years ago 😅)
Does the relationship still make sense with these made up values? 🙃
Hey BD!
What you're saying is true. One will never be able to keep up with 8000 N. The thing is that Mike's results are not in Newton. For them to be that, he should've used SI units. The SI unit for wind speed is m/s, not knots. Also, the made-up numbers are not ideal to get realistic results. However, it does beautifully illustrate Mike's point :)
@@gethighwithmike you're right, it doesn't change the relationship with your made-up values. I've explained why in my answer to BD. Amazing video! :)
Very nice video! I like the physical explanations!
Great video , as always ! Mike , what board size would you recommend for me, being 1.70mt tall , practicing big air/old school on 25knots average. What would be the ideal board size ?
Test many. But probably 134 or 136
Really Amazing breakdown Mike! Thank you!
Unbelievable! Very scientific! Greetings :)
Thanks Mike! Very cool video!
Break the 35m mark…….legend !!
Good content dude👊🏽 love the way you are approaching big air kiting as a science! There should be a master degree of kiting maybe🤔
I think it is also good to name that the “R” (air-density) component depends on air the air temperature, humidity and air pressure. So if you jump in places like the Caribbean the same 25 kts of wind will give you less lift then 25 kts of the cold wind in South Africa or the Netherlands for example!
So if you want to break records, you should also optimize the air density.
Thanks so much dude!
Aaaah yes I totally should have mentioned something about air density in the main takeaways! I didn't want to go too much into detail because I thought it was quite a lot of info already :)
@@gethighwithmike yeah, you’re right! Still good vid dude👊🏽 Maybe an idea for the next video; find the spot with the best density. I think it will be South Africa or somewhere in the North.
Keep up the good work, njeeew!
Always a pleasure to watch this channel, great work.
Super interesting! Thanks dude
Why you injured Mike?
I crashed a jump and damaged both my left knee and right ankle 😅 gonna be out for another 4-6 months, but that's life!
@@gethighwithmike Get well brother!
Excellent video. You're pretty good at this teaching stuff for such a foul mouthed f*****. Ha!
How do you fit this video in with your previous video "Use a bigger kite"?
We were just in Flecheiras on a tour with Andy from Windtown. Brazil is wonderful!!
Please hurry up with that edging video!
Haha thanks Jon!
If you watch my 'You should ride bigger kites' video again, you'll see that I'm not suggesting riding the biggest kite possible in nuking winds. I'm actually encouraging people to get out in light wind on bigger kites because there are some massive benefits! Lighter wind = lower consequences. More practice = more progress. etc. :)
I hope this clears things up! I've heard people misunderstanding this one before haha
Edging video will come in about a week if we're fast! :D Maybe 2. Depends on when we run the BAKL CT comp!
@@gethighwithmike got it. Thanks so much! Seriously. Your instruction is very helpful
@@jondeur2686 Thanks! Stoked to hear that! :D
Good stuff!!
Thanks bro!
This is next level content.
Great vid. Love the breakdown.
Thanks brother!
Do you ship to Brazil?
Unfortunately not hey! Customs there is such a mission. But I do have 3 of my own kites left there for sale. 8, 12 XR7 and 13.5 XR6. All in excellent condition. You can shoot me an email if interested! 🙃
NERD! 🤓
Nice one 🤙
Haha thanks bru!
@@gethighwithmike ok so hypothetical question… hydrofoils sail upwind super fast, like the angle that you can drive the board and generate speed against the wind is far greater than that you can with a tt. Could you theoretically generate more lift with a hf by getting more airflow over the sail due to the higher speed into the wind?
Great video, loved how you explained the formula and of course always like the video inserts. What got stuck in my head, that v^2 is not exponential growth. It's close to it, 2^v would be exponential. Sorry for being a maths teacher. :)
But as said, so much maths in a kite video warms my heart. Well done, Mike.
Yep, you're totally right! Thanks for letting me know 🙌😊