Funnsurfn said..
Recently took master shaper Bert's advice and tried two larger side fins and smaller centre on my ten foot Sunova. Stock Sunova 105 sides and 4.5 Futures centre. After using two plus one in a few different ways. Has really increased the performance and feels faster, looser and more responsive. Just left me a little confused how a ten footer can be set agile. Doesn't want to be surfed slow and cruise. Nose riding now super sensitive, knife edge critical.

whats the height of that side fin Funnsurfn?

colas said..

Funnsurfn said..
. Just left me a little confused how a ten footer can be set agile.

Just experiment, it will open your mind. For instance, try:

- twin fins only
- twin fins + 2 nubsters as quad rears
- asymmetric setups: one twin on the hell side, and half a quad setup on the toe side
...

Cheers always fun to play. Usually I like the bigger centre fin on longer boards. Find I get dishy with smaller fins and really like to engage rail if I can.

JEG said..

Funnsurfn said..
Recently took master shaper Bert's advice and tried two larger side fins and smaller centre on my ten foot Sunova. Stock Sunova 105 sides and 4.5 Futures centre. After using two plus one in a few different ways. Has really increased the performance and feels faster, looser and more responsive. Just left me a little confused how a ten footer can be set agile. Doesn't want to be surfed slow and cruise. Nose riding now super sensitive, knife edge critical.

whats the height of that side fin Funnsurfn?

105 Sunnova stock fin about 5 1/8 inch or 130mm high. 5 inch or 127mm base. Plenty of area. The Sunova Seven Inch cutaway worked great until recent experimentation.

just when i thought i had it wired ....7 sides medium rears on my 8'10 flow ,in lumpy onshore waves ...fins basically where too small ,as standing waiting for waves was a nightmare ....
i will be stashing more fins in my car to change for different conditions ,i'm finding a twin (large) set up with a small rear seems to be the best for
most days ......but it does lack the speed you get from a quad set up needed for a racy reef break and driving turns ..
getting the right size is also another ,choice to be made on the day .

I will be changing fins more offer it seems ...

but when you get it right it like riding on a cloud ... but ripping at the same time ...

I've been playing with this set up lately. I do like the Bert's advice too. These new flux fins are interesting. You've just gotta remember to take a fin-key with you in the surf if you want to change the flexibility out in the surf....

Piros said..
Tardy 7 sides and medium rears is a lot of fin on the Flow . You really shouldn't be relying on fins for stability they are there for performance. Big fins to stabilise your board will just kill it for surfing. The better you get on the Flow surfing with your back foot on the kick and engaging rails you will find you actually drop down in fin size carving tighter arcs and accelerating more out of turns.

Really hard to get a good read on fins in crap conditions , save your fin swap days for clean conditions . Good to see you are changing fins everyone needs to do this , so many people never try it , it's like changing props on a Boat the difference can be amazing.

I think you are right Piros ....i have pulled off better moves with smaller fins ...
last week i was having a ball on clean surf on small fins ...

it was just this one day where the water was moving so fast on a high tide ,on shore day .
and a solid 5 foot... .it was a down the line day ...no fancy stuff ......I'm really trying to pin point what fins work in what surf ...
one fin change today ...had the original smaller 94 's on with a very small rear ,i was just sliding down the face ..no drive
changed the rear fin, to 2 small quad ,fixed it ...
starting to get it ....and realise the flow really is better for me as a quad ...

Me and my mate where out today ,him a surfer ...a big one come in ,we just made it over only to see a massive solid 6-7 footer just about to break
WE dove ,but he smiled as i got dragged ..I come up about 9 metres further in shore than him .i had 90 litre more foam .in my board ..OH WELL .i still caught more waves ..on the day .

thanks for the input .

ooohhh... yeah ...up the tail is the sweet spot for sure ...i love doing floaters ...

the 8.10 requires a little moving around ...but the 8'7 ...tail every time .

Tardy said..
anyone else been experimenting ...

Flex is good, but in a controlled way. Think of your fins as sails, you want the "mast" to stay stiff but the rear part of the "sail" to open up in gusts (for fins, they are the changes of water pressure in turns and in chop) so that the flow stays laminar instead of the pressure building too much and the fin beginning to stall.

Having the whole fin flex, as is the case of low quality fins with not a lot of fibers is bad because the flexing fin is just less efficient without benefits. Forget about the energy storing/releasing, that's b*ll**, the advantage of flex is keeping the laminar flow during turns, keeping speed during th whole turn. However, you may feel so delayed response at the start of the turn.

In my experience:
- it depends on the fin box. I loved stiff carbon fins with the FCS1 boxes, to compensate for the flex at the fin/box connection. But I found out FCS carbon fins were to stiff for me with the tighter FCSII system, with FCS fins I do not go stiffer than the PC construction. But in FCS1 boxes, I still love my nexus carbon fins.
- you want a stiff leading edge, that an be achieved with the fin thickness or some carbon strip there
- I like flex more for carving boards (narrow, pointy tail & nose) with thin rails, for instance I loved the S-Wings(*) on my "mini gun" board, especially in chop where they acted as shock absorbers for buttery smooth carves. For my wider boards, I like stiffer fins for more instant response.
- like you, I like more flex in the rear fins, especially in quads, where you can load up the pressure on the front fins at the start of the turn, and have the board in a kind of "controlled drift" on the rear fins while driving through the turn

(*) S-Wings take the flex concept to the extremes: www.s-wings.surf/en/

7 side 5,5 rear ...that will liven it up .worked with my nalu,

yeah that will do ..i just left the original naish ones on ,which are the same size as a 7 in a FCS. and brought a 5,5 rear what a difference ...it was great ..it made the board feel smaller ...and easier on turns ..i never put the big one back on again .

Slab said..
Thanks, I have a 5.5 centre fin and 5s I can try.....

Piros, Colas......any views?

Personally, on my longSUPs I used bigger side fins with a smaller center, first the Harley Ingleby set, and now the Al Merrick twin fin set + trailer.

Well we've had few days of nice waves over here in the U.K. most have been blown out with strong x-on or x-off and odd states of tides or no waves at all.. a very odd few months TBH. Those few days I've been able to go out I've taken the Flow 8'7, it's too small for our high water boiling rumble but sometimes needs must, it's set with a thruster PCC7's all equal in size.
Today was high, horrid shore dump, yet head high out back so I jumped in and the 400mtr paddle to get across the channel to the sand bar was bad enough, cross rips, lumps, the remainder of wave lumps curling and I got chucked off so many times.. but I progressed, caught 4 decent waves at head high and spent the other 40mins being chucked off and dumped on.. of those 4 waves the bite was nice to have from the Board, dug in nicely and turned sharp with drive..
But that was it, a frustratingly long wait for waves then a whole heap of being chucked off by strong rips and random lumps.

Fin size and placement wasn't really on top on my agenda, more survival

Enjoy surfing lads, love reading this thread.

Slab said..
Why the extra big fins on the sides Coals? What advantage do they give....do they not slow things down?

Actually, side fins are more efficient in turns, especially when you use the rail, where the central fin both loses its traction with banking, and adds drag.

So, basically, single fins are more efficient in a straight line, and side fins in turns. So it depends on your style of surfing.

On the size, big fins add drag, but provide more leverage to push on. So, if you push on your legs in turns, the net result is positive, but if you cruise along it is the opposite. You should experiment to see what works best for you.

colas said..

Slab said..
Why the extra big fins on the sides Coals? What advantage do they give....do they not slow things down?

Actually, side fins are more efficient in turns, especially when you use the rail, where the central fin both loses its traction with banking, and adds drag.

So, basically, single fins are more efficient in a straight line, and side fins in turns. So it depends on your style of surfing.

On the size, big fins add drag, but provide more leverage to push on. So, if you push on your legs in turns, the net result is positive, but if you cruise along it is the opposite. You should experiment to see what works best for you.

Are you using these in bigger more powerful surf? I can really see them working in those conditions but not too convinced in average weaker swell.....but I could be wrong. I use a fish shaped quad too with big fins and find it fast so maybe a twin fin with smaller centre might be worth a try.

how did you find the HI set up? Was it the original black and ref FCS1 set up?

colas said..

Slab said..
Are you using these in bigger more powerful surf? I can really see them working in those conditions but not too convinced in average weaker swell.....but I could be wrong. I use a fish shaped quad too with big fins and find it fast so maybe a twin fin with smaller centre might be worth a try.

how did you find the HI set up? Was it the original black and ref FCS1 set up?

No, I switch back to smaller (normal) fins when it is bigger. In big surf, I find the response of big fins too powerful for me, the board tries to enter the turn before I have had the time to put it properly on the rail.
Most of the time, I use the Al Merrick twin fins in less than shoulder high waves, and the regular Al Merrick set on bigger waves

On the HI setup, I only began to use it with FCSII. On FCS1 boards, I was using only C-Drive fins.

Thanks Colas....going to do a bit of experimenting with set ups today.

I tried my board ( further up this page) today with three same size XL thruster set up. It was awful....so slow to paddle and slow on a wave and sooo much harder to catch the waves. Very noticeable...actually came in early as I found it so frustrating. Back to 2+1 (7 inch plus 3.5 or 4 inch sides) or a 10 single.