Author Topic: Black fish, three fin vs. one  (Read 16014 times)

PonoBill

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Black fish, three fin vs. one
« on: August 26, 2016, 10:19:16 PM »
So I didn't expect a very scientific test since I didn't have a lot of time and I know I'm biased against the Larry Allison three fin setup. Feels draggy to me. But I stuck my speed coach on my new Blackfish and did a few flatwater runs. Three fins, one small center fin, three fins with outer two reversed. Using the Mana 90

Average speed:

Three fins  5.47
One fin  4.9
Fins reversed 5.34

Hmmm.

Then I tried my Konihi 95 which felt terrible after the Mana 90

Three fins 5.74
One fin 5.11
Fins reversed 5.55

Well shit. I'm going to have to try the Konihi 84. I had a suspicion that the Mana 90 wasn't fast in flatwater, but it was just gut feeling. I bet the damned 84 is gonna be fastest. So what does this mean, do I need a paddle for flatwater, a paddle for downwinding, and a paddle for surfing? Seems like we all thought the difference was going to be shaft length in those three disciplines, but is it also paddle design?

Oh, and Larry. You were right. But you already knew that.
« Last Edit: August 26, 2016, 10:22:13 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.

ukgm

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Re: Black fish, three fin vs. one
« Reply #1 on: August 27, 2016, 12:29:49 AM »
So I didn't expect a very scientific test since I didn't have a lot of time and I know I'm biased against the Larry Allison three fin setup. Feels draggy to me. But I stuck my speed coach on my new Blackfish and did a few flatwater runs. Three fins, one small center fin, three fins with outer two reversed. Using the Mana 90

Average speed:

Three fins  5.47
One fin  4.9
Fins reversed 5.34

Hmmm.

Then I tried my Konihi 95 which felt terrible after the Mana 90

Three fins 5.74
One fin 5.11
Fins reversed 5.55

Well shit. I'm going to have to try the Konihi 84. I had a suspicion that the Mana 90 wasn't fast in flatwater, but it was just gut feeling. I bet the damned 84 is gonna be fastest. So what does this mean, do I need a paddle for flatwater, a paddle for downwinding, and a paddle for surfing? Seems like we all thought the difference was going to be shaft length in those three disciplines, but is it also paddle design?

Oh, and Larry. You were right. But you already knew that.

When you went down to one fin, were the empty fin boxes plugged or taped over ? How many runs did you do of each condition - if you list them here, I'll crank out some stats.

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Re: Black fish, three fin vs. one
« Reply #2 on: August 27, 2016, 05:17:06 AM »
When you went down to one fin, were the empty fin boxes plugged or taped over ? How many runs did you do of each condition - if you list them here, I'll crank out some stats.

UKGM, you saw my previous test. I can tell you that in my test I never plugged the empty fin boxes.
Although Larry did send me these plugs with his kit, according to him this is just a mind game for people who like to overthink, since I fall under this category at times. I had to test it and came up with nothing.

Nothing scientific, just few test runs with and without. Hope that helps.
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Night Wing

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Re: Black fish, three fin vs. one
« Reply #3 on: August 27, 2016, 06:42:52 AM »
That is the neat thing with regards to expectations versus experimentation. Sometimes what you expect doesn't jive with the results from experimentation.
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PonoBill

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Re: Black fish, three fin vs. one
« Reply #4 on: August 27, 2016, 06:54:00 AM »
No, I didn't plug them. I'm going to get some plugs from Larry, and some different cant inserts for the proboxes, I also want to try a bigger center fin. I'm going to race this board at the PPG. I decided after torturing myself at the Gorge Paddle Challenge with my surfboard that it was time to stop whining and train on a 14. I'll get some real data for you UK. I need a lot of time on the water with this board, and there isn't any point to training on it without testing results and optimizing the performance for myself.
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blackeye

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Re: Black fish, three fin vs. one
« Reply #5 on: August 27, 2016, 11:42:52 AM »
If the testing were done blind such that the rider didn't know the fin setup, then we'd be talking a bit more testing rigour. This and many many runs would be a way to normalize the rider's effort and remove any bias.

Once we get solid empirical results then we can get on with figuring out the why. 

SUPflorida

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Re: Black fish, three fin vs. one
« Reply #6 on: August 27, 2016, 06:35:26 PM »
Does this translate to other boards? Or just the infinity Blackfish? Am I correct that Infinity has been using that set up for at least a couple years? If the board has been optimized for that fin set up the differences may not be  as dramatic on other designs.

PonoBill

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Re: Black fish, three fin vs. one
« Reply #7 on: August 27, 2016, 06:42:23 PM »
I tried it today on a downwinder, and did NOT like the fins. I don't think Larry intended these fins to be used for a downwinder, do it's no big surprise. I found the board very hard to steer--sometimes it felt like an old school windsurfer that turned in reverse pressure, sometimes it felt like it just wasn't going to turn no matter what. Not conducive to the kind of downwinding I do, which is heavy on steering to extend the ride and connect. I was basically waiting for the board to randomly point where I wanted to go and then pushing hard.

It also seemed to have a sharply defined top speed. At about 9 mph it felt like someone hit the brakes.

I have one of Larry's downwind fins, so I gave that a short test. Much mo' bettah. I'll give it another go soon, but for the next three days I'm going surfing.
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.

ukgm

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Re: Black fish, three fin vs. one
« Reply #8 on: August 28, 2016, 01:33:57 AM »
If the testing were done blind such that the rider didn't know the fin setup, then we'd be talking a bit more testing rigour. This and many many runs would be a way to normalize the rider's effort and remove any bias.

Once we get solid empirical results then we can get on with figuring out the why.

You can't really get that with equipment interventions though so you have to rely on typical statistical techniques to tease out whatever robustness you can find.

ukgm

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Re: Black fish, three fin vs. one
« Reply #9 on: August 28, 2016, 02:01:56 AM »
Does this translate to other boards? Or just the infinity Blackfish? Am I correct that Infinity has been using that set up for at least a couple years? If the board has been optimized for that fin set up the differences may not be  as dramatic on other designs.
Whet interests me are previous comments about the undraftability of a 3 fin set up. If I could get a set up that would be effective on point to point flatwater racing, I'd look to test a system on a board if it provided a competitive advantage.

Area 10

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Re: Black fish, three fin vs. one
« Reply #10 on: August 28, 2016, 08:05:55 AM »
If the testing were done blind such that the rider didn't know the fin setup, then we'd be talking a bit more testing rigour. This and many many runs would be a way to normalize the rider's effort and remove any bias.

Once we get solid empirical results then we can get on with figuring out the why.

You can't really get that with equipment interventions though so you have to rely on typical statistical techniques to tease out whatever robustness you can find.
Certainly, blind trials would be virtually impossible with paddles and boards. But with most fin setups it should easily be possible.

The placebo effect is so strong that tests that don't take it into account are highly suspect. Notice how whenever you get a new board you seem to set a PB soon afterwards? That's most likely the placebo effect in action. Without even being conscious of it, you are cleaning up your technique and trying that 0.5% harder in the belief that your new board or paddle will make you go faster.

I've noticed that the larger the sum of money I've spent, the quicker that new PB happens!

And yes, it could also be that equipment is getting better. But I'm talking about effects above and beyond that.

Trials should really be conducted with several paddlers in order to minimise the placebo effect. Our Australian friends (PT and crew) did an interesting comparison of 14fters of this type a few years ago.

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Re: Black fish, three fin vs. one
« Reply #11 on: August 28, 2016, 01:10:04 PM »
If the testing were done blind such that the rider didn't know the fin setup, then we'd be talking a bit more testing rigour. This and many many runs would be a way to normalize the rider's effort and remove any bias.

Once we get solid empirical results then we can get on with figuring out the why.

There is no such thing as blind testing for the 4 fin vs single fin setups... As soon as you'll get on the board, before even put in a stroke, you'll feel the difference.
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supuk

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Re: Black fish, three fin vs. one
« Reply #12 on: August 28, 2016, 01:43:20 PM »
im not so sure the difference is that large, i would be keen to know how many people could tell there was anything different at all. I have been experimenting today with some new ideas and comparing them all and by feel the differences are all very small and what i did today was with things that you would expect to make a lot larger changes. I think the placebo effect can probably make a larger difference than adding fins

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Re: Black fish, three fin vs. one
« Reply #13 on: August 28, 2016, 02:25:50 PM »
im not so sure the difference is that large, i would be keen to know how many people could tell there was anything different at al...

Is this based on your experience or you're just guessing? Based on my experience there is a noticeable difference in the side to side resistance of the board hence there could be no blind testing. Other noticeable differences, compare to some large surface fins, is the elimination of the "tug" effect I experienced, such in the case of the Future RUNNER. Also very noticeable difference in cross current and turbulent water conditions.
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supuk

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Re: Black fish, three fin vs. one
« Reply #14 on: August 28, 2016, 03:33:28 PM »
from my experience i have been playing with 3 fins for a while now but just fitted the ventral. i could not feel hardly any difference with the rear sides in, the ventral made a small positive difference on the flat but quite a negative difference on the ocean. Considering my board is 21" wide they are quite stable so perhaps it is not so noticeable. The rear fins have been proved to slow the board down it seams and getting extra stability all the way at the tail is never going to be that effective which is why i think the ventral makes a lot more sense in the flat but not in a moving ocean.   

 


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