twin-fins-or-more-on-a-race-board/so it begins

[Luc Benac]

Small ventral, 9 inch elliptical twins and his standard stinger kicker.

When I was still running a Blackfish (big tail, channel) the full Elliptical were my favourite twins among the three. I believe that there are the ones that offer the best release. Regarding kick, for me a light and not very strong paddler, I cannot help feeling that the 6" Stinger is just too much. I should soon receive a new ventral (hollow center) and I am motivated to try it with my Whiplash. I like what Burchas and Larry have been saying about it, specially as I do not paddle in flat water.

[Larry Allison]

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Requadles what you guys say about 4 fins. Here is a average guy going across the Catalina Channel 22 miles on a 27 wide by 14 ft M&M last month. Beating a better rider on a Starboard by 30 minutes I think. This could of never happened in a Single fin world on a M&M, FACT!!! That is Reality my friends!

[Larry Allison]

Thank you guys like Bean, Luc and Stoneaxe in believing  me when converting their boards and understanding their equipment. You guys rock like many others here that follow me like Speedboard another company that pushes more Allison Race Twins.

[Larry Allison]

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  Unfortunately this board got damaged on the way over to Catalina the day before the Channel Crossing by strong winds and the board got thrown off the rack on the boat. But since repaired by me and back in the water.

[Larry Allison]

Now we can get into some new stuff. First again I am super Stoked that ukgm took the lead to support what Thousands already knew but not to the level of numbers that some need even when reality proved it already. I may add that ukgm was not positive about the concept like may of you here but intrigued why so many people were converting their boards with good results. Having the Scientific Mind that ukgm has his wheels starting turning and curiosity got the best of him and now we are here a year later confirming the results that I predicted he would have a year ago. I am honored and humbled that the level of interest from the world brought ukgm on board to ask the questions and seek the answers. Mad respect to you my friend for disrupting the herd. Now here is a peak at a new Board Brand coming out of Marina Del Ray LA called Liquid Athlete. This board design is unique which I was honored by not only getting one of the first boards but had design input. The other concept by this board company is that it comes only as a Allison 4 fin with the right fin options. Here is The Sting Ray 12/6 by 30 for open waters and touring at 25-lbs with fins and boxes.

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[Larry Allison]

Me test riding the Liquid Athlete 12/6 StingRay!

[Larry Allison]

12/6 StingRay by Liquid Athlete.

[Larry Allison]

New Infinity Custom Doug Out with Allison Race Twins. Super proud of Dave creating the Movement even from pressure of people laughing at him. But when you know your product it does not matter what the non believers say. The proof is in the ride Mother Nature will dictate the out come.

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[Larry Allison]

One of my favorite moments was a the Santa Monica Race a few weeks back where Yuval Lavy started at the back of the pack and took first blowing everyone away in his age group of 40 to 49 years old on a 23wide by 14ft Focus running new GTS kick fin with Allison Probox Race Twins. Who said twins are slow, LOL!!!!!!

[Larry Allison]

It has been a fun last 2 months with the market in a fast change. More to share in a few days another board company coming in to market with Allison 4 fins that you will all find interesting a global brand. Dr Wayne riding the StingRay by Liquid Athlete.

[ukgm]

Just to be clear with everyone, let me state what the specification and limitations of my testing involves.

- 8 randomised runs of each fin set up.
- Performed on smooth flatwater.
- No wind.
- Board was 2017 Starboard Allstar, 14ft in a 24.5 width.
- Each run was approximately 250m long and 1:30 in duration.
- Target velocity was 9kph+ (typically 9.2).
- Data was collected from a SUP Speedcoach and corroborated using iPhone sensor arrays.
- To the best of my knowledge, my test methods I use are the most reliable and robust I've seen. They are based upon published peer reviewed test methods of others (adapted from K1 kayaking) and I have had them published too.

In simple terms this means that any results I have produced here are limited (so far) to the context and boundaries listed above. This doesn't mean the concept will work as well on rougher water, on a different board design or at a different race speed (as well as other limitations). It doesn't mean it wouldn't either - It's purely that I haven't tested for that. That would require further testing and investment in time.

In addition:

-The point of me doing this testing was purely curiosity.
-The fins were donated, but the install I paid for.
- I offered no guarantees on the results to Larry and would share them if good, bad or unclear.
- Placebo may or may not be a factor and it cannot be ruled out entirely. Randomised testing and high data run to run repeatability would partially (but certainly not entirely) mitigate for some of this (as a consistent level of placebo is extremely hard to obtain) but more data is needed. I've mentioned this for succintness but to be honest, if there was one, it would be unconscious as my feelings on the system were generally non-plussed.
- I would use the set up for some, but not all kinds of races based on the limitations above.
- The progression of this data is to retest but in more chaotic water states.

I would ask others don't take the results out of context, nor have an axe to grind. I also encourage others take the time to test and let us know what they find.

[ukgm]

Just to be clear with everyone, let me state what the specification and limitations of my testing involves.

- 8 randomised runs of each fin set up.
- Performed on smooth flatwater.
- No wind.
- Board was 2017 Starboard Allstar, 14ft in a 24.5 width.
- Each run was approximately 250m long and 1:30 in duration.
- Target velocity was 9kph+ (typically 9.2).
- Data was collected from a SUP Speedcoach and corroborated using iPhone sensor arrays.
- To the best of my knowledge, my test methods I use are the most reliable and robust I've seen. They are based upon published peer reviewed test methods of others (adapted from K1 kayaking) and I have had them published too.

In simple terms this means that any results I have produced here are limited (so far) to the context and boundaries listed above. This doesn't mean the concept will work as well on rougher water, on a different board design or at a different race speed (as well as other limitations). It doesn't mean it wouldn't either - It's purely that I haven't tested for that. That would require further testing and investment in time.

In addition:

-The point of me doing this testing was purely curiosity.
-The fins were donated, but the install I paid for.
- I offered no guarantees on the results to Larry and would share them if good, bad or unclear.
- Placebo may or may not be a factor and it cannot be ruled out entirely. Randomised testing and high data run to run repeatability would partially (but certainly not entirely) mitigate for some of this (as a consistent level of placebo is extremely hard to obtain) but more data is needed. I've mentioned this for succintness but to be honest, if there was one, it would be unconscious as my feelings on the system were generally non-plussed.
- I would use the set up for some, but not all kinds of races based on the limitations above.
- The progression of this data is to retest but in more chaotic water states.

I would ask others don't take the results out of context, nor have an axe to grind. I also encourage others take the time to test and let us know what they find. Bear in mind this is approximately 8 hours of work I'm sharing for gratis and for conversation.

[burchas]

Just to be clear with everyone, let me state what the specification and limitations of my testing involves...

I would ask others don't take the results out of context, nor have an axe to grind. I also encourage others take the time to test and let us know what they find.

ukgm, I don't think anyone questioned your integrity and the quality of data you provide ( well, maybe one
skeptic here did ), not now and not on the other exceptional tests you provided from time to time.

Your latest test just reiterated and corroborated what many of us already knew, tested and shared here and
other places before. You do have a talent to wrap it in a much prettier package which makes it easier to relate to.

As stated before, if nothing else, your test dispute  the perceived assumption that LA 4 fin system
creates drag. if you want to test that quickly, follow my previous suggestion and run your test again,
you can be biased as you like in favoring the system but you'll be guarantied to be slower.

Now that we got the drag out of the way, we can discuss the 4 fin VS single fin based on their merits.

Obviously you haven't been following this space for that long, otherwise you would remember that some of
us here already posted similar tests here and other places, different boards, different fins same conclusion.

[ukgm]

I don’t know if the system is lower drag or higher drag to be honest.

The:

1) dynamics of the systems fluid flow
2) the total hydrodynamic drag the system creates

......I would say are different things.

I’ve done a little work with the former but haven’t looked at the latter yet. I’ll be able to provide a fuller picture when I have done. My hypothesis is that the Allison system provides higher levels of drag than a single fin but if you get the set up right (fin size, type and position) that some other factor X outweighs it - in some conditions.

[Area 10]

Burchas, I think you misunderstand my intent here.

I am certainly not suggesting that ukgm is wrong. I am completely open-minded on the issue. In fact, if anything I am ready to be convinced: I installed a 3-fin system on my UL board, and found it a tad faster in flat water than the same design but narrower board that has only one fin. I put this down to better tracking while reducing deeper water drag. Nothing more complex than that.

My points instead relate to the conclusions that we can draw from ukgm’s data. Ukgm has, to his credit, spelt these out. But I know very well that people will probably just ignore these critical caveats and jump to conclusions that are not logically justified. And then science (or more probably in this instance, technology) becomes marketing. This is not ukgm’s fault.

Incidentally, I would like to see ukgm rerun his tests on a course that requires “weaving”, or even a circular course. If you install more fins in a board and so it tracks better and is therefore faster in a straight line, this is pretty unremarkable. But the downside of increased tracking can be problems in cross-wind, and increased drag when not going in a straight line. These downsides can easily outweigh the advantages of increased tracking in real-world conditions.