I have to confess that fins are a complete mystery to me. Maybe the only way I will understand the difference is to constantly experiment in the same conditions with different configurations. For example, my Flow is set up with the Sunova supplied quads. What difference would I experience if it had the thruster setup instead? There were times when I struggled to get the speed and drive I wanted. But is that my technique, the wave shape/power at that moment, or the fins? If you slide out in a bottom turn then I can imagine that fins would make a difference, but how else do you know you have the wrong fins?

cantSUPenough said..
If you slide out in a bottom turn then I can imagine that fins would make a difference, but how else do you know you have the wrong fins?

If you are sliding out in a bottom turn it is more likely that you are not committing the paddle to the turn and not putting it in the wave face and getting enough leverage on it to engage the rail and fin cluster. When thinking about fin performance I always think about technique first so I am sure it is not poor riding that is the issue versus the fins not right for me.

obijohn said..

cantSUPenough said..
I have to confess that fins are a complete mystery to me. Maybe the only way I will understand the difference is to constantly experiment in the same conditions with different configurations. For example, my Flow is set up with the Sunova supplied quads. What difference would I experience if it had the thruster setup instead? There were times when I struggled to get the speed and drive I wanted. But is that my technique, the wave shape/power at that moment, or the fins? If you slide out in a bottom turn then I can imagine that fins would make a difference, but how else do you know you have the wrong fins?

cantSUPenough: I have done a ton of experimenting with my 8'7" Flow like yours. All different sizes in all kinds of different combinations. When I tried the quad setup that comes with the board (5.125" fronts and 4.75" rears) it was too much fin area for me (75 kilos). I spent quite a bit of time experimenting with different thruster combinations, and then went back to playing with quad setups which make sense on that board because of the widish tail. I went down as small as 4" fronts and 3.5" rears, and the board was super loose but I lost too much drive. For now I have settled on 4.5" fronts and 3.5" rears, and it is working great for me. I have a theory that one reason a lot of people feel that quads are stiffer than thrusters, especially with SUPs, is that they are running rear fins that are too large. I have read about others like myself who experimented with very small rear quad fins, and found the best of both the drive of a quad and the tight turning of a thruster. Maybe start by playing with that idea.

Thanks for your comments (and sorry for hijacking Tardy's thread ). You said "way too much fin area" - how did you know? Was it too stiff to turn? To me the combination of speed, wave-shape, and especially back-foot location makes such a huge difference that I am not sure how you know what the contribution is of the fins.

Hi jacking is good ..we learn off each other .
I went back to a tri fin today ,and moved it up the front ,,,Far to loose..lost all my drive .
wobbly as all hell ..and side ways most of the time ..I didn't mind it but ..kept sliding down the face and couldn't get back up ,as well.had to pump ..it was small and choppy ..but a steep face
I am using the original fins up front which are 5 I think ..
i put 2 x5 in the rear to start ..but just to much fin ...
now running 3 carbon FCS ..real drivey ...if there is such a word.the hokua s are pretty wide in the tail ,the sunova looks narrower ..
so you will have less lift .so won't need as bigger fin.you really have to change sizes to see what fits each board, as they will be all different .
The raptor howevery will stay a quad for ever ..its like riding a cat on Acid ...it doesn't sit still.
I am glad I kept the larger 9.6 Hokua its a great board for big waves ..and that rocker is a must for the free falls ...where as my 9.5 mana was a nose diver
cantsupenough ..if its barrelling i would take the higher rocker board ...or take both to be sure . never surfed there ...depends how quick the wave is .
you might need the extra speed ..then it would be the flatter rocker board .???and depends how vertical you want to get.

With my 6'5" which is kind of smaller Raptor, mainly on back side I can afford to hang deeply some steep face or getting closer or nearly in with little knubtsers
Was on Quad before , I won't believe this kind of 5 fins effect before I try it. I get that board a lot more confident now.

i think Kami's board has a thruster setup with 2 rear Nubsters.

Tardy said..
Interesting board kami ...very short.
what do you mean when you say
I get the board more confident ??
Its better with five fins ? or your surfing good on it now with the five fins rather than 4. .?
me no savee.

Hello, yes this board is a minimum volume to my weight but once you get use to this narrow space of confort, it's so good to take off earlier but ride (almost) as a normal surfboard.

I mean more reliable. Before I ride this board with quatro made of TC red line at front and rear quad GX-Q. That combo of Quad was loose and drivey but since I rode this same board as a thruster I found it better in hollow wave ( 3 or 4 ') so I tried the thruster combo with Nubster and I find this combo of 5 fins with all advantages from both Thruster and Quad
As said by Lucyloo "i think you are on the right track by trying different fins in the same session.It will take a lot of the guess work out of it." As you can watch on the picture on my board up here, there is many fin plugs to try different fins position too.
Many thanks Cobra to say something serious once upon the time

The other thing about changing fin set up from quad to Tri and different size and flex of fins is that you learn something new about the how the board works in terms of rocker, tail width, tail kick, bottom shape for speed, drive etc. With different set ups you might get more rail in the turn or a snappier top turn off the tail or slower/faster on the face. I experiment a lot with fins for wavesailing and with windsurfing you get a lot of feedback as you are going so much faster and loading up the rail and fins much more in bottom turns driving power down through the rig. I experiment with my SUP fins in the same session and make notes in www.sessionlogs.com so I can refer back to my thoughts later to see if I still feel that way about the set up and fins. Mostly my first impressions are correct so I have started to build some insights into what I want from the board in the conditions that I ride with style of riding I like to do. The biggest problem is getting to try different fins before buying. I took a punt on the FCS Nexus H-3 as scored some second hand and very happy with them but they get mixed reviews in surfing reviews.

Stev0 said..
The other thing about changing fin set up from quad to Tri and different size and flex of fins is that you learn something new about the how the board works in terms of rocker, tail width, tail kick, bottom shape for speed, drive etc. With different set ups you might get more rail in the turn or a snappier top turn off the tail or slower/faster on the face. I experiment a lot with fins for wavesailing and with windsurfing you get a lot of feedback as you are going so much faster and loading up the rail and fins much more in bottom turns driving power down through the rig. I experiment with my SUP fins in the same session and make notes in www.sessionlogs.com so I can refer back to my thoughts later to see if I still feel that way about the set up and fins. Mostly my first impressions are correct so I have started to build some insights into what I want from the board in the conditions that I ride with style of riding I like to do. The biggest problem is getting to try different fins before buying. I took a punt on the FCS Nexus H-3 as scored some second hand and very happy with them but they get mixed reviews in surfing reviews.

Good comments ...what about fibreglass vs. carbon ,as far as flex goes ...to me carbon is alot more rigid .but you can get good power .
because fins are so short on SUPS ...DO you think the different composites make a different s ...Im using surfboard fcs 3 carbons on the rear ,naish fibre glass on the front .I really think a new set of fins could change the feel again ,having all been made of the same material .
i hate been over fined ,it makes it to difficult to turn at a drop of a hat ..I think I should make notes like you ..good idea .
All I know now, is to take all fins to the beach .

its a bit like going windsurfing and taking one sail.and 1 x fin ,or one board ..doesn't happen.thats a hole new thread....

Seems counter intuitive to fit extra fins in big waves. I can see a quad working on a sup, tails are wider then surfboards so carving along a steep wall the two wave side fins are doing most of the work plus you have a paddle to overpower the fins if necessary. Still, seems like a lot of lift when going fast.

Interesting topic.

I have a mate who doesn't have a quad set up on his board ...he keeps his back fin loose and kicks it back on the track in the surf ..if it has
any size ....
he has **** loads of trouble kicking it the other way .ouchie..he reckons.

Tardy said..
redthumb I have a few surfing mates that have guns ...they don't even have a centre fin insert ...quads only they love em on the big ones .
surfers are always changing fins ...

Yeah your right, googled it and found lots of pics of guns with mostly quad setup. Also plenty of articles and theories about why they are better. Reduced drag is the common theme but I am struggling somewhat with that idea. 4 fins with toe in has less drag then 1 large fin? Possible depending on fin size, location, toe in angle.

Up to now i thought quads where just a fashion thing, seems there is more to it...

All good Kami ....I'm intrigued with the five fin set up ... And interesting shapes ...

cantSUPenough said..
I was naturally going much faster than normal so it is hard to say whether the quads on the Flow were now making it more difficult to turn (it seemed more stiff) or whether it was just me.

I certianly perfer my Flow as a thruster in everything but really little stuff.

As a quad it is fast but the turns are way too flat, and you end up squirting out to the shoulder and a way from the pocket. As a thruster it is much easier to surf the board more vertically, and gives more control in bigger faster waves , slowing it down just a touch so you stay in the pocket.

boundeast said..
similar issues here--often a long walk, or tricky rocky painful walk out, or as in recent excellent storm surf around here, tought paddleouts, incl the occasional shutdown--then there's that i am hustling to squeeze a sesh in before work or family sched

so the concept of swapping fins during a sesh usually doesnt work for me

i do know that i prefer quads generally--i feel like my wider boards work better in steeper bigger waves--could be imagined, but they feel faster, and feel like they get better bite on a steep face i need to hold to make sections

and paddling around waiting for waves in a windy sloppy lineup feels much more stable on quads, all else equal, to me

was on my old allwave 8'11" (153 ltr) with thruster and it felt tippy as hell compared to my 8'8" airborn (120 ltr) with quads--punched a whole in the airborn last monday and stayed out to enjoy OH sesh--thing needs to dry out--so i repaired mu dinged allwave for this past weekend. i was expecting it to feel rock solid, but it felt tippy compared to the airborn---prolly gon sell the allwave now--and get off my ass to repair the airborn!

That's an interesting comment about the stability waiting out the back...especially when comparing the 153 ltr to the 120 ltr! Board shape, corkiness, and other factors come in to play but if you weight anything like me (92 kg) then 120 ltr should always feel tippier.