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

[Bean]

I would like to hear some thoughts about the specific fin configurations of displacement boards vs. planing-boards.  While no flat water SUP is purely one or the other, clearly boards like the Infinity Blackfish lean more toward planing and might benefit from lift and possibly other forces provided in a multiple fin configuration.

[Larry Allison]

The Twin Race movement has come a long way. Thought I would share some show and tell. Please feel free to jump in my friends. Mahalo, Larry

http://www.supracefins.com/uncategorized/twin-fins-or-more-on-a-race-board/

I just noticed this on this thread, www.supracefins.com is not me "Larry Allison". My Facebook "Sup Races Fins" since 2009 is me "Larry Allison" In late 2013 my Facebook name was registered by another Sup Brand which I found out later part of 2014 and discontinued doing business with this Brand which also hijack my name "Larry Allison" in google search. This creates confusion in the Sup Market which I have requested the Brand to remove my name from their sight with little luck as you can see when google searching Allison Race Fins or Larry Allison Sup Fins. Not sure how this www.supracefins.com got into this thread. Thank you my friends for your support! Please no negative comments on this tech thread over this name issue, I just wanted to make my Sup Friends aware. Mahalo,Larry

[Larry Allison]

Hi my friends, Here is video number 1 just talking about fin box placement and why. Feel free to ask any questions to help me better explain as we go to the next video talking Ventral Fin next week. Mahalo Larry

[hefwiezen16]

A while back I installed Twin boxes on my 2014 All Star, following Larry's placement instructions.    Works like a champ!   In my 1st race using twin fins was pretty flat, I was thinking that it would be too much fin for the day,  but feedback I got after the race was that attempts to draft me were thwarted by my weird wake.  However, that same wake that prevents drafting, causes more drag,  I believe the fin area was too big for conditions, and took 3rd by just a few meters.   I then picked up a smaller set that worked equally well, not as stable, but faster.     
      My next race,  I went single for a few reasons  and was drafted most of the race (DOH!), losing out on a podium spot in a sprint for the finish.     Dag Nabbit!!!     A few months later at a local event I went  twins, and once again, no one could draft me, allowing me to slip away, unfortunately it wasn't from the leaders, just the chase group I was with.
     Twins work!

[Larry Allison]

A while back I installed Twin boxes on my 2014 All Star, following Larry's placement instructions.    Works like a champ!   In my 1st race using twin fins was pretty flat, I was thinking that it would be too much fin for the day,  but feedback I got after the race was that attempts to draft me were thwarted by my weird wake.  However, that same wake that prevents drafting, causes more drag,  I believe the fin area was too big for conditions, and took 3rd by just a few meters.   I then picked up a smaller set that worked equally well, not as stable, but faster.     
      My next race,  I went single for a few reasons  and was drafted most of the race (DOH!), losing out on a podium spot in a sprint for the finish.     Dag Nabbit!!!     A few months later at a local event I went  twins, and once again, no one could draft me, allowing me to slip away, unfortunately it wasn't from the leaders, just the chase group I was with.
     Twins work!

Hef, Thanks for sharing. Can you post a pic so I can see what you were running to help you out my friend.

[SUPflorida]

Larry....is there a three fins configuration that will work without the ventrical fin? I would love the triples in the rear but really don't care for the look of the ventrical fin. Having another fin to deal with so far forward on the board, having to remove it to put the board in a bag or stacking boards for transport... While a small thing is annoying if you have deal with it every paddle.

[Henrik F]

Larry....is there a three fins configuration that will work without the ventrical fin? I would love the triples in the rear but really don't care for the look of the ventrical fin. Having another fin to deal with so far forward on the board, having to remove it to put the board in a bag or stacking boards for transport... While a small thing is annoying if you have deal with it every paddle.

Don't bother about the look of the ventral fin! It is a click-it fin and you can remove and put it back in a second. The ventral is so good for tracking, stability, side chop downwind, downwind and of course upwind. It helps in every direction. I have had it since early 2013 on three different boards. The ventral should be standard equipment on every raceboard produced. It is that good. The only drawback is that you have to step a little further back when doing a pivot turn.

Henrik F

[Larry Allison]

Picked up my Ron House Coastal Cruiser today from Larry, with a fresh set of ProBox + Triple delight fins.
The set up looks killer, and workmanship is top notch.  I was anxious to get it in the water, so went directly to my usual spot in Torrance Beach, where I paddle up/down the beach breaks and around the peninsula, surfing sand bars and reefs.
1-2 ft swell, 5 knot winds, and some surface texture today.

My first impression upon hopping up on my board was "WOW"!!  This thing is super stable.  Much more so than with any previous single fin on this same board.  The dramatic increase in stability made my board feel like it was 1-2" wider!! I previously paddled this board with the stock Riviera "SR" fin, Gladiator Hybrid, and Ninja single fins.  The current Triple Delight felt rock solid in the surf zone and light chop.  Tracking was straight and true also.

Paddled into a few waves, and the 12'6" responded confidently.  Coming off the bottom turn, the board shot back up the face, and the fins locked into the upper 1/3 of the wave face, with no slippage.  Dang....this is cool!!
Couldn't resist paddling back out and repeating same scenario:)

Bonus: Kelp shedding is a non-issue with these shorter, and raked fins.
Our rocky coastline is heavily surrounded by thick mats of kelp.  The fins skimmed over the carpet with no hiccups.

Thanks Larry--this Triple Delight set up is perfect!!!!

Supflorida, In answer to your question about using a Ventral, Henrik said it best in the post before this. If you are using a board like this coastal runner pic below and review here, then a Ventral Fin can be opted out. I will talk more about Ventral in video number 2 my friend in detail to better answer your question. Mahalo

[Larry Allison]

Thanks my friends for making the move to Allison Race Twins. It seems that now that boards are running higher volume it seems guys are going to ProBox Finsystems for Twin conversions. It makes sense, A single fin is a pivot point, break the pivot point into two and now you get it. Got a text 4 weeks ago from a company in PR, MHL. The laminator said Larry we are making a 14' by 21" race board. Need to talk fins. The results are here from the owner of this 21" wide board.


Review:

Robert Norman
May 6 at 7:08pm · Inverness, FL ·
Running the Larry W. Allison probox on the bottom of the new 21 inch board.
Spent this afternoon playing with a few different fin combinations.
My first impression is: I'm working a lot less to achieve the same overall speed based on the fins I'm running.
Everyone is saying the probox design creates too much drag and you're gonna be going slow. Not the case at all. Take a typical single fin and break it into four smaller pieces then place them in advantages spots on the board to promote glide and stability... that's the concept... and my first impressions agree.
The lateral stability is night and day with the triple fins on the tail vs one larger center fin.
And the overall tracking is superior with the ventral fin and small center fin vs a single center fin of equal cumulative size.
The extra stability translated into more energy I could transfer to the paddle to make the board move quicker... and there's no increase in drag as a price to pay. And the fins help project the board in a straighter line each stroke without that "over-finned" feeling.
I'll be racing this setup and training on it indefinitely, as I use it more I'll update more but my initial impressions are very positive.

[Larry Allison]

This setup has the new Small Blkfish Twins for guys under 180lbs. Along with the 6" Stinger kick and small Ventral. Working with Dave Boehne for a little over 3 years dialing this board in, I feel we have all the bases covered. Thank you Dave for pushing the envelope.

On another note:
Any sup board 25 inches or under should be running this set up to ride. Allison Race Twins with Ventral are proven to be as fast or faster than a single fin. But riding a board at 25 inches wide as a single becomes a balance act due to a single fin being a pivot point. ALLISON PROBOX RACE TWINS adds 3 to 4 inch of stability without adding drag. Don't believe me ask a Racer or Sup rider that has Race Twins on their board. Again I repeat this all the time, Allison Race Twins are a Sup Set up the OPPOSITE of Surfing.

[Larry Allison]

Published on Jun 14, 2016

Finologist Larry Allison shares a video by Malissa Austin showing Erick Kuaffman who is 230lbs, 6'4" tall paddling a 14'by 26 wide Blackfish Infinity into a strong head wind. This Board is finned with Allison Probox Blackfish Twins at 4.5" tall by 11" long with a 7 1/2" tall Jr.Dolphin Keel for a kick fin along with a 2" by 7" Long Allison Ventral fin assist. What Finologist Larry Allison wants to bring to your attention: is the glide of the Infinity Raceboard going into the wind with a Allison multiple fin set up. Notice the board still moving forward with stored energy from the multiple fins as Eric switches paddle stroke sides. This does not happen with most single fins going into a head wind. The end result here is more fins in the right placement and size do not show a drag response like so many theroize without riding themselves.

[SUPflorida]

It's always hard to get a true representation across with a video...and Larry I want to believe in the multi fin concept...but this particular video looks pretty normal to me, as these are typical conditions where I paddle. Video makes it look more of a "toilet bowl" chop situation then wind...but the again looks can be deceiving...
If anything, rather than locked in, the tail looks a little "skatty" to me.

[FloridaWindSUP]

I'm not so sure about the multi-fins for racing. The superman board guy Robert Norman is obviously very fit, but he was pretty far off the pace (9th of 10 racers) in the recent Battle of the Blueway race where he went with 4 fins. Winner Ryan Helm finished in 1:16, I finished in 1:22, Robert in 1:31.

https://paddleguru.com/races/BattleontheBlueway

In a shorter length race earlier this year Robert went with a single fin and beat a lot of the same racers that beat him in the blueway race. 

[ukgm]

It's like anything - perform a robust fin test experiment (and I don't  mean looking at race results or a dataset of just one paddle) and then draw a meaningful conclusion from it.

I am curious to see if two small fins on a flatwater board is faster than one big one. If nothing else, it might allow the manufacturers to drive down width of a board further whilst maintaining stability or improving out and out speed.

[kayadogg]

I think board design will affect how well twin fins or a single fin will work. Larry has been working with Dave Boehne for a couple years now on dialing in this type of setup specifically for Infinity's Blackfish model. The bottom contour is designed with twin fins in mind. This is not to say that it won't work with a single fin or that twins on another board won't work either. Personally speaking, I've owned a couple Blackfish over the past couple years and have had pro boxes installed in each one so I've ridden my boards as single, twins and tri-fin setups in a range of conditions. There are times when I prefer one setup over the other and I don't believe there's any set formula, it's all a matter of personal preference.