by Pierre Milutin
Previous article from the same series: Speedsurfing Tuning Tips 4
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11. Fin trim
There are a lot of fins on the market. The best thing to do is do your reaserch on the net. Check up web sites and other gps sailers to see what's goin on.
You need a fin that you can trust and off course you have to go through the hard yards to test these fins. So, be prepared.
In speedsailng there is no law in what fin size you have to use to make the board effective. This is something you have to try out, to see what works in what conditions.
For example, on my Mistral speed 55 wide I will use a 28 cm from sail sizes 6.3 to 7.0 and maybe even a 7.8 which i still have to try out. But on a 5.6, I would go down to 23 to 26 cm fin.
Always remember: the lighter the wind gets the bigger the fin you have to take. Alos, the choppyer the water, the bigger the fin you have to go to. Speeding in choppy waters with a very small fin and very well powered up, is a death wish.
In lighter winds you have to go bigger due to board lift. If you are on a small fin in light winds you dont get board lift, so your board sticks to the water too much and that causes drag. You have to go bigger to get the board out of the water and get it smoking on the tail.
The next thing is fin stiffness. A good fin has some decent flex in the tip, while the mid section is stiffer. Why? When you drive the fin with your back foot it will bend the fin tip to give you lift. The mid section holds that constant lift.
A too soft fin will break down and you will loose the power and create drag on you board, so it can't hold on to the power.
A too stiff fin will create a lot of lift and then you loose controll of your power and equipment especially in chop.
So, if you are a heavy rider, then a stiffer fin will work better for you in flat water and also choppy water. However, it all depends how stiff it is, so if you can't gain controll your equipment then your fin is too stiff. Of course, that is valid only if you got the right setup for the right conditions.
So, this ends up doing the hard yards in testing and buying fins. It can get costly if you want the top preformance.
Wide based fins are only good in flat water, but I dont think they are faster, due to too much profile area. And they are dangerous in choppy waters. They only work to a certain degree in choppy waters. For me, up to 38 kts, maybe 40 kts, they work. Above that… I wish you luck.
12. Body postion
The most common body position and the most effective is to sit in your harness. Meaning, you use your weigth to sit in the harness and keep the upper body straigth, not leaned out. Front leg locked, in and the back leg with a little bit of a bend or more "personal choice".
With this kind of stance, your lower body from waste down holds the rig. It is not your arms holding it, and at the same time you produce the power through your legs onto the board giving perfect trim and explosive consistant power.
Why have the upper body straight? Because you put more weight onto holding the rig with your body and putting more weight onto the board means giving it control in choppy waters and producing more speed and power. This comes down to more drag racing and slalom technique.
As for speed, it's the same principle, but once your nearly off the wind, then you have to be light on the feet. The more pressure you put on the board the more drag you create. In speedsailing, your weigth is only there to be able to hold the sail down and have total controll over it. That makes you go faster. That's why you see big guys wearing weight jackets and the weight sits all on "top of the shoulders". On that way you can hold the sail in mega gusts with your body, and not with your arms, but still light as possible on your legs.
If the sail is ripping out of your arms, the couse of that is not enough weight on your shoulders, or the sail is to big for the conditions you are out in!
Speedsailing is a special discipline, so you have to take into account some important info and tunning to get the top speed.
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The end of the series Speedsurfing Tuning Tips by Pierre Milutin
Previous article from the same series: Speedsurfing Tuning Tips 4
_____
11. Fin trim
You need a fin that you can trust and off course you have to go through the hard yards to test these fins. So, be prepared.
In speedsailng there is no law in what fin size you have to use to make the board effective. This is something you have to try out, to see what works in what conditions.
For example, on my Mistral speed 55 wide I will use a 28 cm from sail sizes 6.3 to 7.0 and maybe even a 7.8 which i still have to try out. But on a 5.6, I would go down to 23 to 26 cm fin.
Always remember: the lighter the wind gets the bigger the fin you have to take. Alos, the choppyer the water, the bigger the fin you have to go to. Speeding in choppy waters with a very small fin and very well powered up, is a death wish.
In lighter winds you have to go bigger due to board lift. If you are on a small fin in light winds you dont get board lift, so your board sticks to the water too much and that causes drag. You have to go bigger to get the board out of the water and get it smoking on the tail.
The next thing is fin stiffness. A good fin has some decent flex in the tip, while the mid section is stiffer. Why? When you drive the fin with your back foot it will bend the fin tip to give you lift. The mid section holds that constant lift.
A too soft fin will break down and you will loose the power and create drag on you board, so it can't hold on to the power.
A too stiff fin will create a lot of lift and then you loose controll of your power and equipment especially in chop.
So, if you are a heavy rider, then a stiffer fin will work better for you in flat water and also choppy water. However, it all depends how stiff it is, so if you can't gain controll your equipment then your fin is too stiff. Of course, that is valid only if you got the right setup for the right conditions.
So, this ends up doing the hard yards in testing and buying fins. It can get costly if you want the top preformance.
Wide based fins are only good in flat water, but I dont think they are faster, due to too much profile area. And they are dangerous in choppy waters. They only work to a certain degree in choppy waters. For me, up to 38 kts, maybe 40 kts, they work. Above that… I wish you luck.
12. Body postion
With this kind of stance, your lower body from waste down holds the rig. It is not your arms holding it, and at the same time you produce the power through your legs onto the board giving perfect trim and explosive consistant power.
Why have the upper body straight? Because you put more weight onto holding the rig with your body and putting more weight onto the board means giving it control in choppy waters and producing more speed and power. This comes down to more drag racing and slalom technique.
As for speed, it's the same principle, but once your nearly off the wind, then you have to be light on the feet. The more pressure you put on the board the more drag you create. In speedsailing, your weigth is only there to be able to hold the sail down and have total controll over it. That makes you go faster. That's why you see big guys wearing weight jackets and the weight sits all on "top of the shoulders". On that way you can hold the sail in mega gusts with your body, and not with your arms, but still light as possible on your legs.
If the sail is ripping out of your arms, the couse of that is not enough weight on your shoulders, or the sail is to big for the conditions you are out in!
Speedsailing is a special discipline, so you have to take into account some important info and tunning to get the top speed.
_______
The end of the series Speedsurfing Tuning Tips by Pierre Milutin
Many thanks for your comments Pierre (and posting it Adrian), I am about to enter my first speed national event at age of 49! It was about time! Regards, Pioneer Pete.
ReplyDeleteGood luck and great speed, Pete! (It's never too late and 49 is still young!)
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