Author Topic: Weird Konihi 95 Blade  (Read 21388 times)

PonoBill

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Weird Konihi 95 Blade
« on: July 14, 2014, 09:41:23 PM »
This new Ke Nalu blade is going to spark a lot of conversation. I've paddled it twice now, and I have no idea what it's doing or how it's doing it. I'm paddling with a compromised shoulder, but I think I have a pretty good impression of the performance. It will only get better from here. I'm being very careful with technique, so I think that actually helps my assessment.

First--it's weird. Smooth as glass, but very noisy. I would normally associate noise with inefficiency, but it certainly doesn't seem inefficient. I was putting in moderate effort and holding 4.8 MPH on my F16 in Nichols basin. Both directions. That's weird by itself. Usually my speed rises and falls, but with a comfortable level of effort I was doing 4.8--steady.

Second--it has two vortices, very close to the shaft. And they are big. I'm sure that's the source of the noise. Most SUP paddles have four vortices, including the original Ke Nalu blades. One hideous blade I tested had six and was trying for eight. I haven't stuck the Konihi in my water tunnel yet--it's a pain in the ass to set that thing up. But I'm going to have to. This thing has my curiosity piqued.

I have it on a 100Flex shaft and it feels really good. One of the guys at Big Winds has his 95 on a Xtuf(S) and loves it, and has an 84 he's also using but I didn't ask about the shaft. He said the 84 is really fast but it feels like he's not doing any work and the cadence is high. My cadence with the 95 is moderate--possibly because of the shoulder. It feels like a bigger blade, like a 105, except if has no wobble or vibration at all. So little that actually feels a little dead.

I tried some hard, sudden pulls to induce wobble--nothing. Then I gripped the shaft tight with my lower hand and fought the blade a little--nothing. I could barely twist it. Sucker is rock steady.

Bottom line, I think this is my new go-to race and downwind blade. I need to experiment more, and we'll see how it works when my shoulder is better, but for right now, I think I can be faster with this blade. Noisier, but faster.

Its going to be very interesting to see what everyone else thinks. If nothing else Lane has added a whole 'nother level of tuning to the current range. I haven't used any other paddle that feels like this thing does.
« Last Edit: July 14, 2014, 09:47:26 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

stoneaxe

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Re: Weird Konihi 95 Blade
« Reply #1 on: July 15, 2014, 07:01:09 PM »
Oh shit....I've been trying to resist....Sue is gonna shoot me.

Hey...just had a thought....how about bringing it with you?...or you could just bring a blade. I'd like to check it out, I'm sure the crew will be interested too.
« Last Edit: July 15, 2014, 07:04:02 PM by stoneaxe »
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

PonoBill

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Re: Weird Konihi 95 Blade
« Reply #2 on: July 17, 2014, 05:10:22 PM »
I am bringing it. I found the secret to eliminating the noise--and nearly all the vortex--shove it deep. I have it on a fairly short shaft to cut my shoulder some slack. I was keeping the neck above water. I got it a few inches deeper and it's noiseless. the vortex comes up right along the shaft. Never seen that before. Totally quiet, zero flutter, zero vibration. I think Lane is on to something here.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

AJR

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Re: Weird Konihi 95 Blade
« Reply #3 on: July 17, 2014, 06:56:07 PM »
Good for surfing too you think?



shankfoo

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Re: Weird Konihi 95 Blade
« Reply #4 on: July 17, 2014, 07:02:10 PM »
I was gonna say the noise has gotta be coming from somewhere -- if it wasn't fluttering and it wasn't cavitating (!) then it must be pulling down air bubbles...
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OUTSIDEWAVE

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Re: Weird Konihi 95 Blade
« Reply #5 on: July 17, 2014, 07:53:43 PM »
x2  on surfing with it. less stress on shoulders? or more/
SEA BIRDS THEY DO TOUCH AND GO AS THE WORLD JUST TANGOES BY.... SO I SADDLE UP MY SEAHORSE WITH MY FLYROD IN MY HAND.... 10'3 King custom  10'6"  c4 da beachboy

PonoBill

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Re: Weird Konihi 95 Blade
« Reply #6 on: July 17, 2014, 08:15:50 PM »
Probably good for surfing depending on your technique.. I'm taking it easy on my shoulder, but it has a progressive kind of power that I think will work well in surf. I didn't have motion-X going for my whole run, but I did just after wells island. 5.5 MPH all the way. Of course there were endless micro swells to catch, but the speed was very consistent with only a few dips--probably where I took a rest for a few strokes. Bill Worthington was right alongside me when we passed wells, his Bullet 17 was catching the swells a little better than my slipper-nose F16. But when we got to the flatter water headed for the Nichols he disappeared behind me. I was kind of head-down, chugging away in Diesel mode. I thought he might have fallen, but apparently not. When I was putting the board on the truck he walked by with his board and said "Man, you humbled me."

I really think it was the paddle, I just plunked away.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

blackeye

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Re: Weird Konihi 95 Blade
« Reply #7 on: July 18, 2014, 11:48:48 AM »
I found the secret to eliminating the noise--and nearly all the vortex--shove it deep.

I would assume the vortex is still there, just deeper and less interaction with the surface.

The Ke Nalu site used to have some of your material on the physics of paddling, but now its gone. Any chance of resurrecting that for us? An update with regard to Lane's wings would be very interesting.

I can see how your concave wings would become unstable. If flow across the blade face is uneven, and in real world almost always is, the face has a twisting force on the shaft axis when the flow encounters the wing/fence. As it twists it presents more surface area on that side of the blade that twists forward (away from the rider) and generates even more twisting force. Lane's convex winged Konihi blade would do the opposite and thereby self correct.

I'm not sure I get Ke Nalu's comparison of the Konihi's wings to the winglets of an aircraft wing. The paddle is essentially in a perfect stall whereas the winglets are moving tip vortices away from the laminar flow of the wing.

SUP-poser

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Re: Weird Konihi 95 Blade
« Reply #8 on: July 18, 2014, 09:13:53 PM »
Though the paddle may work terrific, their notion that the "winglets" are analgous to a modern airplane's winglets seems misguided. The catch and initial pull of a paddle doesn't have much in common with the slicing action of a wing, rotor, or propellor; all of which pass through air or water edge-on. A paddle is more like the blades on an old paddle-wheel river boat or a fully stalled wing during most of the stroke, though I think my stroke finishes with an outboard slicing motion resembling the arc of a propellor blade. I think some call this a "J" stroke? Maybe "sculling?" Even so, for a "winglet" to function on a slicing paddle motion like this it would have to be on the low pressure side of the tip of the paddle, not the long edges, and one of the long edges of the paddle would be the "leading" edge, the other the "trailing." In the initial part of a normal paddle stroke the large faces of the paddle are perpendicular to the direction of its motion, not parallel, or nearly parallel to what aerodynamicists call the "relative wind" as with a wing. None of this theoretical stuff may alter the Konihi's utility or value of course, but it seems like they have a pseudo-scientific explanation for why it works.
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LM

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Re: Weird Konihi 95 Blade
« Reply #9 on: July 21, 2014, 05:27:54 AM »
Though the paddle may work terrific, their notion that the "winglets" are analgous to a modern airplane's winglets seems misguided. The catch and initial pull of a paddle doesn't have much in common with the slicing action of a wing, rotor, or propellor; all of which pass through air or water edge-on. A paddle is more like the blades on an old paddle-wheel river boat or a fully stalled wing during most of the stroke, though I think my stroke finishes with an outboard slicing motion resembling the arc of a propellor blade. I think some call this a "J" stroke? Maybe "sculling?" Even so, for a "winglet" to function on a slicing paddle motion like this it would have to be on the low pressure side of the tip of the paddle, not the long edges, and one of the long edges of the paddle would be the "leading" edge, the other the "trailing." In the initial part of a normal paddle stroke the large faces of the paddle are perpendicular to the direction of its motion, not parallel, or nearly parallel to what aerodynamicists call the "relative wind" as with a wing. None of this theoretical stuff may alter the Konihi's utility or value of course, but it seems like they have a pseudo-scientific explanation for why it works.

You're kind of missing the point, it's not so much about direction of travel as pressure differential. The way you are seeing things is looking a little too much at Newton's laws but forgetting about Bernoulli's principle (which basically explains how pressure differential causes lift). In fact the vortices that cause problems in aircraft wings ARE actually travelling perpendicular to the direction of flight (which is a pretty amazing feat in itself considering the speeds involved, but it just goes to show how much pressure differential there is...and of course has to be in order to generate lift).  For some strange reason it's difficult to find an accurate explanation with a Google search, most websites are only focusing on how the vortices are made smaller with winglets but it's the drag that's caused by the vortices making contact with the upper wing surface that's the real issue (for airplane performance). This video my Puerto Rican distributor found kind of shows it: https://www.youtube.com/watch?v=Lc86Akaq3KQ  . Keeping this in mind take a new look at it & consider the pressure differential. Paddling creates high pressure on the blade face & lower pressure on the blade back, the vortices created are the effect of the high pressure seeking an area of lower pressure (and the idea that a paddle is planted & not moving like if it were in concrete is pure fantasy, if it were true there would be no vortices). There is no question these vortices are there, what the Konihi winglets do (just like an airplane wing) is direct the vortices out and away from the blade back leaving a "cleaner" condition for the paddle. However, they also have the added benefit of being a physical opposing force to any sideways motion of the blade, this also would greatly improve blade stability. Finally, regarding this: "I can see how your concave wings would become unstable" (not your post, I know) I don't even know what a concave wing is but I can certainly say it's not on a Konihi...in the end guys, it's really pretty simple stuff; it's good to read all the discussion but don't think about it too much...get out & try one, if you like it great, if not at least you'll know. But I can say this, the feedback we've been getting so far is phenomenal. 

stoneaxe

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Re: Weird Konihi 95 Blade
« Reply #10 on: July 21, 2014, 06:53:52 AM »
Regardless of the reason behind it. Trying IS all it takes. I paddled Bill's on Saturday and tried very hard to make it flutter, full lower hand tight grip on the shaft, pulling as hard as I could, even twisting the shaft, no flutter. It actually feels weird, like it's not doing anything. It almost makes the paddle feel dead at first. I started the run with a Molokai w/ 100 flex. I was paddling my old Starboard 12-6, Bill was on his rocket ship Speedboard 18 with the Konihi on (I think) an xtufS. I was having a hard time keeping up with him even though he was just paddling lightly. We swapped paddles. My 1st impression was that I didn't like the feel and that it was going to be underpowered for me. Then I tried hard for a few minutes to make it flutter with zero effect. Truly bizarre, I've never had a paddle in my hands that I couldn't make flutter by trying. I thought I felt the beginnings of some flutter but that was only if I was pulling hard past my feet in really bad form.

I paddled it the whole way back. Faster cadence with what felt like no effort at all. I tried to match what I felt the level of effort was (not cadence but effort) while I had been chasing Bill before and he seemed to be paddling with about the same effort as before. Certainly not scientific but there's no question I had an increase in speed even on my old heavy starboard. The feel is going to take some getting used to but i also noticed there seemed to be a lot less stress and strain on my arms. Most noticeable in the shoulders but also in my elbow some. I think it's the zero flutter. You don't notice all the fine muscle micro adjustments that even slight flutter requires....multiply that by 1,000's of strokes in a race. So faster with less muscle strain....should come in a little blue pill.... ;)

Bill what size was that one? I felt like I could go bigger, like there was still some reserve.
« Last Edit: July 21, 2014, 06:57:18 AM by stoneaxe »
Bob

8-4 Vec, 9-0 SouthCounty, 9-8 Starboard, 10-4 Foote Triton, 10-6 C4, 12-6 Starboard, 14-0 Vec (babysitting the 18-0 Speedboard) Ke Nalu Molokai, Ke Nalu Maliko, Ke Nalu Wiki Ke Nalu Konihi

JimK

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Re: Weird Konihi 95 Blade
« Reply #11 on: July 21, 2014, 02:40:40 PM »
I'm now way as learned on this topic as the other posters
Here is my simple position
Konihi 84 works GREAT in the surf! Why I'll leave that to others

JimK
www.extremewindsurfing.com

blackeye

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Re: Weird Konihi 95 Blade
« Reply #12 on: July 22, 2014, 10:06:11 AM »
Hi Lane - I like to know how stuff works, in particular before I consider buying things.

I finally saw one in the flesh a few days ago. They look and feel great.

By concave I was referring to the orientation of the wings. I see yours as essentially convex. If the paddle blade was a dinner plate, Bill's would have the food/concave side pushing water but yours would have the table/convex side pushing water.

And by "your wings" I was referring to Bill's experiments, not the Konihi. I can see how the Konihi self-stabilizes while Bill's would become unstable.
« Last Edit: July 22, 2014, 10:17:20 AM by blackeye »

LM

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Re: Weird Konihi 95 Blade
« Reply #13 on: July 22, 2014, 11:29:48 PM »
Hi Lane - I like to know how stuff works, in particular before I consider buying things.

I finally saw one in the flesh a few days ago. They look and feel great.

By concave I was referring to the orientation of the wings. I see yours as essentially convex. If the paddle blade was a dinner plate, Bill's would have the food/concave side pushing water but yours would have the table/convex side pushing water.

And by "your wings" I was referring to Bill's experiments, not the Konihi. I can see how the Konihi self-stabilizes while Bill's would become unstable.

...Fair enough, I think my confusion came from referring to the winglets as wings. Granted, even me calling them winglets is a bit of a stretch but that's where I got the idea. But they're really not "wings". Also (to me) calling them either concave or convex is a bit off mark. I really don't mean to nit-pick & this isn't a personal "stab" at you, it's really just semantics, what "concave" means to me might be different to what it means to you. To me the winglets would better be described as protrusions off the blade; concave it what's visible laying a straight edge across the blade face (when you "rock" a straight edge to either side of the dihedral, there's a bit of concave there & also a very slight amount in the catch). Anyway, I'm just trying to help avoid any confusion to those who might be reading this without ever seeing the blade. There have been a couple other posts with pictures but here's a couple that show the winglets.

PonoBill

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Re: Weird Konihi 95 Blade
« Reply #14 on: July 23, 2014, 05:24:14 PM »
For anyone trying thr Konihi, the key to getting full performance is to sink the blade fully. You're always supposed to do that, but the Konihi requires it. If you don's the vortices suck air and reduce the power. If you sink the blade to the neck or beyond, the vortices attach to the shaft and theres very little noise. The apparent catch increases right away too, so it must be at least a 10 percent difference. You can feel that for yourself easily. Just stroke the paddle with a little of the neck showing. Ignore all the noise and just feel the catch, then lean forward a bit more and get the neck fully submerged. Not only does the noise go away, but there's a sudden  and very obvious increase in catch
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


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