Fin selection for freeride board

Lucab,
The fin length will depend on a number of factors, including wind strength. Fin quality is as important as length.
It's not likely that 1 fin will match both your smaller sails. For your 5.8m, probably 32 cm in normal conditions and 30 cm when powered up (you mention 30 kt gusts). For the 4.7 cm, 26 cm and 24 cm powered. The 42 cm stock fin may be a bit big for the 7.3 m E-pace - a 39 cm may work better.

Given your equipment, you might be interested in the comments section of this video. The poster has a lot on YT, demoing North/Duotone gear and is quite generous in replying to questions.

Good luck.

Thanks everybody for the replies! So do you think that having a smaller fin than 42 would be ok with the board tail width? Just to avoid cavitation, spin out and guarantee good uphaul attitude?

On the 133l Fanatic When on the 7.2M sail the standard 42cm (presuming its the choco raked tip) is ok-not great.
A good 40cm pointer will be faster and more responsive if your in controll (especially in the gibes).
With your 5.8 a 30/32cm pointer same caviat as above,
For the 4.7 a 24 or 26 pointer.
That board will however be well on its limit in 30 knots it will want to 'wind walk' on you due to its footprint, so a raked fin to help regain controll as a second fin for that sail may be necessary on those full on days.
Fin size will not affect uphauling much,

Great advices from everybody, thanks a lot! Terrific forum!

Hi Lucab, yes for sure put a smaller fin on when the wind picks up .carbon fins do behave a lot better in overpowered conditions ,or a more swept back fin will also help the tail sit down and behave better .On most manufacturing windsurfing websites for boards they will give you a fin range for the board ,which is quite helpful ,eg.my 127 liter isonic has the fin range of 38-44 .so I agree with other post that a 38 would be a good size for your weight ,
have you thought of buying a smaller board .? For the high wind days ,that would be the better choice in my opinion ,a 100-115 liter board would still give you uphauling ability at your weight .

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Tardy said..
Hi Lucab, yes for sure put a smaller fin on when the wind picks up .carbon fins do behave a lot better in overpowered conditions ,or a more swept back fin will also help the tail sit down and behave better .On most manufacturing windsurfing websites for boards they will give you a fin range for the board ,which is quite helpful ,eg.my 127 liter isonic has the fin range of 38-44 .so I agree with other post that a 38 would be a good size for your weight ,
have you thought of buying a smaller board .? For the high wind days ,that would be the better choice in my opinion ,a 100-115 liter board would still give you uphauling ability at your weight .

Hi Tardy, yes I have thought about a smaller board and I will surely add to my rig soon. The main issue is that I am still having trouble with waterstart, so I thought to buy a 105L freewave as soon as I master the waterstart. Of course, second fin (workaround) vs second board (the fix) cannot be compared (performance, cost, etc)

4.7 is way to small for that board in my opinion, if you get those conditions often you should definetly consider a smaller board even if it is second hand and older.

With the 5.8 I would recommend something between 33 - 35. I would personally go for 35cm and would work you well up to 20 something knots (with 30knt gusts u will still be way to overpowered and will probably have to open sail alot). Just as comparison, I learned windsurfing in a 125lts with a 36cm fin and mainly using 6.4 up to 20knots (70kg).

The ideal setup for your board is definetly the 7.3 and 42cm fin .

Well I am still able to uphaul with 4.7, fortunately I have a good balance and force. For example, I am able to duck jybe up to 15 knots quite easily (I have practice it sooooo many times....) ??

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Francone said..
I have bought a new board last fall, a Bic Techno Wind Foil 160 . For the moment I don't envisage using a foil. This board is made for planing, but I'll be sub-planing most of the time, because the winds are usually light around here, mostly 12knts, rarely rising beyond 15 knts. The board has a central removable fin under the mast foot, coupled with a 30 cm long rear fin which I find too small to provide adequate lift in light winds and is not very effective upwind, even with the central board screwed on. I wonder if a longer fin, around 40 cm will help
I weigh 90 kg and I will use a 7 m. sail.
I wonder if anybody has .suggestions or comments on this.


Thanks
Francone

Yes, it's in the name of your board... there are good used foils available now and it will transform how many days you find pleasurable. You've asked about this for a couple of years and the answer remains the same.

To answer your fin question, yes, a longer fin will help even up to a 48 or so. Get a good quality relatively upright (freeride/freerace) fin if you can - unless you have weeds.

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Francone said..
1 Are there any disadvantages in using too long a fin, aside from damaging it in very shallow water?

Too big a fin will develop a lot of power in windy conditions and demand a fair amount of back foot pressure to keep it under control. The board will become unruly more quickly with too big a fin.

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2. What determiners the appropriate length of a fin ? Is it the sailor's weight, the sail's size? the wind speed? is a 48 cm fin a better all-around fin for light winds than a 40 cm fin ?

Both the board width at the rear footstraps - which determines to a good extent how much leverage we can exert on the fin; and wind speed/expected board speed. In light wind conditions, we need the fin to develop more lift since the board can only move so fast through the water (I'm assuming 12-16 kts). When it's windier, and the sail has little trouble giving you enough power to move quickly, the board is traveling fast enough that a smaller fin will develop enough lift for you.

Naturally, a heavier rider will exert more force on the fin so can tolerate a slightly larger fin. Sail size is related to wind and board speed. You'll typically be using big sails in light winds where just getting and staying on a plane is your primary goal. When it's windier, you have, usually, sufficient power to getting and staying on plane.

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3.. I have been windsurfing for a number of years ( without claiming any proficiency beyond the strictly intermediate level,) , but I was spoiled for having always used an " unsinkable" (!) board like a 12 ft Bic Windsup. You never fall with it!
Now with a shortboard like the Bic 160 , my balance is severely put to test, even more so that I am 80 and age affect the sense of balance .
I can still manage, but I wonder if a longer fin would help stabilizing the board,, so that I don't have to..dance my way around" to keep balance , like when I used it for the first time last fall. It would be a welcome added bonus.

Not in a significant or noticeable way. A foil, however would as they are significantly longer and, more importantly, heavier. I see all the time 85-95kg guys on 135-145 l. foil boards. For most people with a normal sense of balance, it's a technique issue. I will speak in generalities here since you may already be doing all of the following things. One most be more mindful of (when not planing) keeping their feet on the centerline and not pressing unnecessarily on the heels especially when trying to counter force on the sail. They should remind themselves to press down with the balls of the feet which are towards the middle of the board. Make sure they aren't in the habit of looking down, at the water, at feet, athands, etc but instead looking up and out at horizon level. This is a big part of "balance". Your board is 82cm wide which is a good comfortable width.

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4. I was also wondering if the center fin interacts with the longer rear fin. Should it be kept on or removed, if I use a 40 or 48 cm rear fin?

Not in any way different than it does a shorter rear fin. We used to race longboards all the time with 44-48cm fins. However, a longer rear fin should be sufficient for going upwind. Unless you are going out on a day when you are sure you aren't going to plane, I'd leave off the front fin as, imho, it will make board handling a bit strange, add drag and not really improve things overall in any conditions where there is a chance you'll plane. Most of us sailing shortboards, even smaller ones, are fine without any sort of center fin.

A last note - it seems in looking at the specs of your board that the center and rear fin were intended for pretty early in the learning curve and they assumed, as the user increased skill level, they would be transitioning to a windfoil. Similar width Bic/Tahe boards such as the Techno 148 and 293OD came with 46-48 cm fins.

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Francone said..

Paducah said..

Francone said..
I have bought a new board last fall, a Bic Techno Wind Foil 160 . For the moment I don't envisage using a foil. This board is made for planing, but I'll be sub-planing most of the time, because the winds are usually light around here, mostly 12knts, rarely rising beyond 15 knts. The board has a central removable fin under the mast foot, coupled with a 30 cm long rear fin which I find too small to provide adequate lift in light winds and is not very effective upwind, even with the central board screwed on. I wonder if a longer fin, around 40 cm will help
I weigh 90 kg and I will use a 7 m. sail.
I wonder if anybody has .suggestions or comments on this.


Thanks
Francone

Yes, it's in the name of your board... there are good used foils available now and it will transform how many days you find pleasurable. You've asked about this for a couple of years and the answer remains the same.

To answer your fin question, yes, a longer fin will help even up to a 48 or so. Get a good quality relatively upright (freeride/freerace) fin if you can - unless you have weeds.

Thanks
1 Are there any disadvantages in using too long a fin, aside from damaging it in very shallow water?

2. What determiners the appropriate length of a fin ? Is it the sailor's weight, the sail's size? the wind speed? is a 48 cm fin a better all-around fin for light winds than a 40 cm fin ?

3.. I have been windsurfing for a number of years ( without claiming any proficiency beyond the strictly intermediate level,) , but I was spoiled for having always used an " unsinkable" (!) board like a 12 ft Bic Windsup. You never fall with it!
Now with a shortboard like the Bic 160 , my balance is severely put to test, even more so that I am 80 and age affect the sense of balance .
I can still manage, but I wonder if a longer fin would help stabilizing the board,, so that I don't have to..dance my way around" to keep balance , like when I used it for the first time last fall. It would be a welcome added bonus.

4. I was also wondering if the center fin interacts with the longer rear fin. Should it be kept on or removed, if I use a 40 or 48 cm rear fin?

Thanks

Francone

Get an "Indo Board" balance trainer, or something similar, it is remarkable how it will train your balance for windsurfing, or windfoiling.

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Paducah said..

Francone said..
1 Are there any disadvantages in using too long a fin, aside from damaging it in very shallow water?

Too big a fin will develop a lot of power in windy conditions and demand a fair amount of back foot pressure to keep it under control. The board will become unruly more quickly with too big a fin.

2. What determiners the appropriate length of a fin ? Is it the sailor's weight, the sail's size? the wind speed? is a 48 cm fin a better all-around fin for light winds than a 40 cm fin ?

Both the board width at the rear footstraps - which determines to a good extent how much leverage we can exert on the fin; and wind speed/expected board speed. In light wind conditions, we need the fin to develop more lift since the board can only move so fast through the water (I'm assuming 12-16 kts). When it's windier, and the sail has little trouble giving you enough power to move quickly, the board is traveling fast enough that a smaller fin will develop enough lift for you.

Naturally, a heavier rider will exert more force on the fin so can tolerate a slightly larger fin. Sail size is related to wind and board speed. You'll typically be using big sails in light winds where just getting and staying on a plane is your primary goal. When it's windier, you have, usually, sufficient power to getting and staying on plane.

3.. I have been windsurfing for a number of years ( without claiming any proficiency beyond the strictly intermediate level,) , but I was spoiled for having always used an " unsinkable" (!) board like a 12 ft Bic Windsup. You never fall with it!
Now with a shortboard like the Bic 160 , my balance is severely put to test, even more so that I am 80 and age affect the sense of balance .
I can still manage, but I wonder if a longer fin would help stabilizing the board,, so that I don't have to..dance my way around" to keep balance , like when I used it for the first time last fall. It would be a welcome added bonus.

Not in a significant or noticeable way. A foil, however would as they are significantly longer and, more importantly, heavier. I see all the time 85-95kg guys on 135-145 l. foil boards. For most people with a normal sense of balance, it's a technique issue. I will speak in generalities here since you may already be doing all of the following things. One most be more mindful of (when not planing) keeping their feet on the centerline and not pressing unnecessarily on the heels especially when trying to counter force on the sail. They should remind themselves to press down with the balls of the feet which are towards the middle of the board. Make sure they aren't in the habit of looking down, at the water, at feet, athands, etc but instead looking up and out at horizon level. This is a big part of "balance". Your board is 82cm wide which is a good comfortable width.

4. I was also wondering if the center fin interacts with the longer rear fin. Should it be kept on or removed, if I use a 40 or 48 cm rear fin?

Not in any way different than it does a shorter rear fin. We used to race longboards all the time with 44-48cm fins. However, a longer rear fin should be sufficient for going upwind. Unless you are going out on a day when you are sure you aren't going to plane, I'd leave off the front fin as, imho, it will make board handling a bit strange, add drag and not really improve things overall in any conditions where there is a chance you'll plane. Most of us sailing shortboards, even smaller ones, are fine without any sort of center fin.

A last note - it seems in looking at the specs of your board that the center and rear fin were intended for pretty early in the learning curve and they assumed, as the user increased skill level, they would be transitioning to a windfoil. Similar width Bic/Tahe boards such as the Techno 148 and 293OD came with 46-48 cm fins.

Thanks Paducah. Good advice.
I think the mistake I was making when trying out the new shortboard , was the front foot position. I was keeping the ball of the foot towards the edge of the board, near ( or in) the outer footstrap. and this was probably tipping the board to the side and throwing me off- balance, because I didn't have sufficient speed to compensate ( like on bicycle)

I even wonder if,when subplaning , I should worry about the footstraps at all and keep the feet, rather , on the centerline, near the mastfoot. The rear foot is OK because I have only one footstrap in the back near the centerline. THis is what I had always being doing when sub-planing on the Bic Windsup.

I think you are right when you say that I should perhaps remove the front fin when subplaning. In fact, a few times I had the weird sensation that the board was kind of turning under my feet, unable to keep a straight course . In other words the board would not respond to the tack or gybe. Perhaps this is what is called a spinout.
I thought that it was because the rear fin was too short and tended to come off the water with the board bobbing up and down in the chop.

Thanks for the input

Francone

I work on guys method -

seems to work for me.