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Mast Position vs Adding Shims

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Lamilu
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Mast Position vs Adding Shims

Postby Lamilu » Fri Jan 21, 2022 8:13 pm

Moving off Fone Mirrage…1000 Carbon
Where my best equilibrium was mast totally back…
It was a “no adjustment” foil.
Mast back also gave me “more” board to land and make a transition landed…
Just about to recieve a Sabfoil set and a new variable comes into play… (W695+S399)
Shims.
How should I go about this…
Try to see where to put the mast and no Shim?
Keep the mast in familiar position and try to compensate if necessary?
I hear Gunar say “this foil with this stablizer I use 0.5 degrees”…
Is that a given? Always true? Start by that?
Anyways, I know they reduce speed and should be avoided.
Just dont want to waste more energy than needed.
How should I go about this?
Does anybody use the same Sabfoil set?
Thanks

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Re: Mast Position vs Adding Shims

Postby drsurf » Sat Jan 22, 2022 1:11 pm

Simple.
Get the foil, attach it to the board in the middle of the track without shims and go out and see how it feels and make adjustments to suit your needs and conditions.

There are way too many variables to make hard and fast decisions on your new setup. There are personal preferences for the way different people like to ride, there are variable wave and wind conditions, skill level and so on. You might find the first time you try the foil it's perfect for you but over time your preferences and skill level may change. Or you might find the foil challenging but with use you learn to ride it better as you get used to its specific characteristics.

Considering you are going from a 1000 sq cm freeride foil to a 770 sq cm wing that according to SAB is: "An advanced wing, full of speed and maneuverability. The W695 is the perfect choice for all those riders who aim to jump high and do maneuvers at high speed," at 110kg you're going to need more wind and skill to get the best out of this new setup.

Do the forum a favour by trying your equipment first and then provide feedback or questions then as many of us have done over the years. That way everyone benefits.

Lamilu
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Re: Mast Position vs Adding Shims

Postby Lamilu » Sat Jan 22, 2022 9:01 pm

:thumb:
Correct...
Will do...
Forgive my lazy anxiety...

grigorib
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Re: Mast Position vs Adding Shims

Postby grigorib » Sun Jan 23, 2022 1:15 am

With 91/101/111 masts you’d want you back foot big toe to be behind line of rear holes of mast plate. If you’re using 82/92 or RDB 70/90 masts you should have you back foot big toe in front of the line of rear holes of the mast plate.

If you can’t move the mast any further forward and still have too much back foot pressure (or not enough foil playfulness) - shim stabilizer a bit down. 1mm plastic washer on the front bolt between the stabilizer and the fuselage would do. You can cut out and sand down a pretty shim out of an old credit card

Don’t use shims if you can move mast to an ideal position.
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Cefirmeza
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Re: Mast Position vs Adding Shims

Postby Cefirmeza » Sun Jan 23, 2022 11:51 am

grigorib wrote:
Sun Jan 23, 2022 1:15 am
With 91/101/111 masts you’d want you back foot big toe to be behind line of rear holes of mast plate. If you’re using 82/92 or RDB 70/90 masts you should have you back foot big toe in front of the line of rear holes of the mast plate.

If you can’t move the mast any further forward and still have too much back foot pressure (or not enough foil playfulness) - shim stabilizer a bit down. 1mm plastic washer on the front bolt between the stabilizer and the fuselage would do. You can cut out and sand down a pretty shim out of an old credit card

Don’t use shims if you can move mast to an ideal position.
What if there is plenty of mast placement but I want to reduce induced drag from the stabilizer and add more speed and looseness feel?

There is no information about how it is possible to improve performance and glide of the foil just by tuning the incidence angle of rear wing more neutral.

Depending on the foil use and personal preference shims can be used not just for mast and feet placement.

grigorib
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Re: Mast Position vs Adding Shims

Postby grigorib » Sun Jan 23, 2022 11:58 am

Cefirmeza wrote:
Sun Jan 23, 2022 11:51 am
grigorib wrote:
Sun Jan 23, 2022 1:15 am
With 91/101/111 masts you’d want you back foot big toe to be behind line of rear holes of mast plate. If you’re using 82/92 or RDB 70/90 masts you should have you back foot big toe in front of the line of rear holes of the mast plate.

If you can’t move the mast any further forward and still have too much back foot pressure (or not enough foil playfulness) - shim stabilizer a bit down. 1mm plastic washer on the front bolt between the stabilizer and the fuselage would do. You can cut out and sand down a pretty shim out of an old credit card

Don’t use shims if you can move mast to an ideal position.
What if there is plenty of mast placement but I want to reduce induced drag from the stabilizer and add more speed and looseness feel?

There is no information about how it is possible to improve performance and glide of the foil just by tuning the incidence angle of rear wing more neutral.

Depending on the foil use and personal preference shims can be used not just for mast and feet placement.
That’s a good point. As far as I know Moses 450 was their only stabilizer with messed up AoA - pointed too much down and it needed such correction to ride it normally.
Otherwise I’d rather be choosing thinner and/or smaller one instead, usually race stabilizers come into picture for that and they improve things more than shimming. What I mean you can shim 483 all you want but good old 425 will be better anyways for more speed and play. Folks riding waves and looking for least yaw stability pick 370 or similar flat stabilizers.

On the opposite side - if I want a wing to go slower, even a freeride wing like 695 or 730, I replace my good old 425 with RDB 310 and it has effect of almost a larger surfier wing. I know Gunnar is not in favor of that view but I tried riding 720 wing with 325 vs 450 stabilizers side by side and difference in take off speed and ease was very much there. As well as overall stability and reversely cruising speed

Ultimately, a monowing gets very smooth not having stabilizer at all - I posted a quick feedback on Hoverglide H4 ridden without stabilizer few years back.

Yet to original question - the 695 is not a race wing, you won’t achieve more speed by reducing AoA of a stabilizer and 399 is racy as it can be, I wouldn’t shim it unless I can’t move the mast

There’s very little official info on most of kiting gear, which leaves room to buy it experiment, post feedback and learn from others who post theirs
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Cefirmeza (Sun Jan 23, 2022 12:21 pm)
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Re: Mast Position vs Adding Shims

Postby Peter_Frank » Sun Jan 23, 2022 7:37 pm

I would also say, that shimming the stab closer to neutral to get less drag thus more speed, the change in drag is minimal and not possible to feel, almost non existent IMO.

Whereas having it shimmed neutral means you can handle a lot more power and speed changes, in balance, thus you are able to ride faster because of that :thumb:

8) Peter

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Re: Mast Position vs Adding Shims

Postby taiguy » Mon Jan 24, 2022 5:35 pm

I've been riding the W695 with the S421 and a small plastic washer as a shim. I'm about your weight and can get it moving pretty easily compared to the W590 (and needs more than the W633). I ride a 42" KS board and have the mast in the forward position with the W695. Strapless, so mast position can be compensated by moving feet around.
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grigorib
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Boards: Spleene RIP 37, Flysurfer Radical6 138, Flysurfer Flydoor5 XL, Slingshot/Moses/RDB 70/90/101cm masts with 1200/860/800/730/600 kitefoil or 2200/1700/1400 wingfoil wings and 310/230/425 stabilizers, Naish MicroChip 80cm, 36" Woody, Slingshot Dwarfcraft Micro 100, MBS Comp 95x

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Re: Mast Position vs Adding Shims

Postby grigorib » Tue Jan 25, 2022 2:20 am

taiguy wrote:
Mon Jan 24, 2022 5:35 pm
I've been riding the W695 with the S421 and a small plastic washer as a shim. I'm about your weight and can get it moving pretty easily compared to the W590 (and needs more than the W633). I ride a 42" KS board and have the mast in the forward position with the W695. Strapless, so mast position can be compensated by moving feet around.
Where is your back foot toe positioned compared to the mast plate rear bolts line?

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Re: Mast Position vs Adding Shims

Postby taiguy » Wed Jan 26, 2022 5:39 pm

grigorib wrote:
Tue Jan 25, 2022 2:20 am
taiguy wrote:
Mon Jan 24, 2022 5:35 pm
I've been riding the W695 with the S421 and a small plastic washer as a shim. I'm about your weight and can get it moving pretty easily compared to the W590 (and needs more than the W633). I ride a 42" KS board and have the mast in the forward position with the W695. Strapless, so mast position can be compensated by moving feet around.
Where is your back foot toe positioned compared to the mast plate rear bolts line?
It changes frequently since my front foot position isn't in the same spot every time. I aim for center of the back pad and go from there.


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