Author Topic: Foot placement over mast.  (Read 7340 times)

Badger

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Foot placement over mast.
« on: February 12, 2023, 03:14:04 PM »
Where should my rear foot be in relation to the mast? Some people ride with their foot over the leading edge of the mast, others over the trailing edge, and some directly over the mast. Is one way better than the other? Is it just personal preference, or does it have more to do with the board/foil combination?

I learned to ride with my foot over the leading edge just because I was more comfortable there. Now with my new Kalama, my foot wants to be farther back. I don't want to develop any bad habits. Is there an optimal spot over the mast where I should be trying to keep my foot?
Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

Hdip

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Re: Foot placement over mast.
« Reply #1 on: February 12, 2023, 09:54:54 PM »
Balance the board as best you can. Straddle the center of lift (the front foil) after it's all balanced up. A lot of brands are moving the placement of the front wing in comparison to the fuse, so you might have to move your mast placement. Worry about the front foil in regards do your feet, not the mast.

Dontsink

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Re: Foot placement over mast.
« Reply #2 on: February 12, 2023, 11:42:09 PM »
The front wing is what holds you up.

It is better to set your position using the front wing as a reference point,not the mast.

The center of lift is  about 1/3 of the width  from the leading edge.
A stance that straddles that CofLift is a good starting point as Hdip wrote.



A Takuma foil will place the mast further back than a Naish or Armstrong.But the front wing will be roughly in the same place for all brands.

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Re: Foot placement over mast.
« Reply #3 on: February 13, 2023, 01:50:51 AM »
The front wing is what holds you up.

It is better to set your position using the front wing as a reference point,not the mast.

The center of lift is  about 1/3 of the width  from the leading edge.
A stance that straddles that CofLift is a good starting point as Hdip wrote.



A Takuma foil will place the mast further back than a Naish or Armstrong.But the front wing will be roughly in the same place for all brands.

Even using these estimations is misleading.  The centers all change when sweep, margin, area, volume, etc change.  This calculator is great for watching them move.  https://www.ecalc.ch/wingdesigner.htm.  And theat is just for the front foil. 

Best practice, avoid all of these rules of thumb.  This really blew us up as new riders. 
« Last Edit: February 13, 2023, 03:38:08 AM by Admin »

Badger

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Re: Foot placement over mast.
« Reply #4 on: February 13, 2023, 06:28:30 AM »
Awesome info, thanks. I knew there had to be a better way to visualize it.

Unlike the Naish board, the new Kalama requires the Axis mast plate to be all the way forward for equal foot pressure. I'm using a single extra-long front foot strap set all the way forward. Centering my stance over the center of lift puts my rear foot directly over the mast which seems perfect. I can't wait to try it again with this new understanding.



Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

Dontsink

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Re: Foot placement over mast.
« Reply #5 on: February 13, 2023, 12:36:37 PM »
The front wing is what holds you up.

It is better to set your position using the front wing as a reference point,not the mast.

The center of lift is  about 1/3 of the width  from the leading edge.
A stance that straddles that CofLift is a good starting point as Hdip wrote.



A Takuma foil will place the mast further back than a Naish or Armstrong.But the front wing will be roughly in the same place for all brands.

Even using these estimations is misleading.  The centers all change when sweep, margin, area, volume, etc change.  This calculator is great for watching them move.  https://www.ecalc.ch/wingdesigner.htm.  And theat is just for the front foil. 

Best practice, avoid all of these rules of thumb.  This really blew us up as new riders.

Cannot agree...
First of all this rules of thumb are an initial setup method.
KdMaui balance method to place the mast in the boxes, straddle the CofLift to place straps if you use them.You will be in the balllpark with most brands and foil/board combos.

Fuse,stab,shims,sweep,Armstrong kinkiness... are going to need further adjustment but most foils are pretty similar and will need little tweaking.

IMHO what really screwed beginners (and still does)  is  the fact that foils are not intuitive, understanding the forces they create takes new knowledge for most people,and for the first years most distributors,shop owners,pros etc... could ride the things really well but understod little of why or how to explain it.

So they stencilled those blasted markings on the foil box (more wind-less wind :(  ) and got busy selling them things.

Rant over,sorry...

Badger

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Re: Foot placement over mast.
« Reply #6 on: February 13, 2023, 01:57:38 PM »
If my mast plate is all the way forward in the tracks and I find that I still don't have enough front foot pressure, would adding a mast plate shim help?
Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

Califoilia

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Re: Foot placement over mast.
« Reply #7 on: February 13, 2023, 04:08:35 PM »
If my mast plate is all the way forward in the tracks and I find that I still don't have enough front foot pressure, would adding a mast plate shim help?
If I'm understanding you correctly, if you have too much lift from your wing and mast position (...don't have enough front foot pressure), you need to move your mast rearward to take out lift, before adding any shims to your mast or rear tail.

Edit: If I read that wrong, and you meant that you don't have enough lift in order to use your front foot to pressure the nose of the board down for better pitch control of the board/foil throughout your runs...then yes, if you're all the way forward, you could start by shimming the stab so from level, the trailing edge is higher than the leading edge.

I'd try that before starting to trim the baseplate, which more or less just changes the ride level of the board when the foil is riding flat/level, and doesn't change the overall riding lifting characteristics of the foil as shimming the tail does.
« Last Edit: February 13, 2023, 04:18:49 PM by Califoilia »
Me: 6'1"/185...(2) 5'1" Kings Foil/Wing Boards...7'10 Kings DW Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

Badger

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Re: Foot placement over mast.
« Reply #8 on: February 13, 2023, 05:02:01 PM »
If my mast plate is all the way forward in the tracks and I find that I still don't have enough front foot pressure, would adding a mast plate shim help?
If I'm understanding you correctly, if you have too much lift from your wing and mast position (...don't have enough front foot pressure), you need to move your mast rearward to take out lift, before adding any shims to your mast or rear tail.

Edit: If I read that wrong, and you meant that you don't have enough lift in order to use your front foot to pressure the nose of the board down for better pitch control of the board/foil throughout your runs...then yes, if you're all the way forward, you could start by shimming the stab so from level, the trailing edge is higher than the leading edge.

I'd try that before starting to trim the baseplate, which more or less just changes the ride level of the board when the foil is riding flat/level, and doesn't change the overall riding lifting characteristics of the foil as shimming the tail does.

I was rear-foot heavy with the mast in the back of the tracks. I moved the mast forward to help equalize the pressure of both feet ending up with the mast all the way forward.

I will try the +1-degree shim in the stab and see if that helps. Thanks for the suggestion.   8)

Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

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Re: Foot placement over mast.
« Reply #9 on: February 14, 2023, 01:51:48 AM »
The front wing is what holds you up.

It is better to set your position using the front wing as a reference point,not the mast.

The center of lift is  about 1/3 of the width  from the leading edge.
A stance that straddles that CofLift is a good starting point as Hdip wrote.



A Takuma foil will place the mast further back than a Naish or Armstrong.But the front wing will be roughly in the same place for all brands.

Even using these estimations is misleading.  The centers all change when sweep, margin, area, volume, etc change.  This calculator is great for watching them move.  https://www.ecalc.ch/wingdesigner.htm.  And theat is just for the front foil. 

Best practice, avoid all of these rules of thumb.  This really blew us up as new riders.

Cannot agree...
First of all this rules of thumb are an initial setup method.
KdMaui balance method to place the mast in the boxes, straddle the CofLift to place straps if you use them.You will be in the balllpark with most brands and foil/board combos.

Fuse,stab,shims,sweep,Armstrong kinkiness... are going to need further adjustment but most foils are pretty similar and will need little tweaking.

IMHO what really screwed beginners (and still does)  is  the fact that foils are not intuitive, understanding the forces they create takes new knowledge for most people,and for the first years most distributors,shop owners,pros etc... could ride the things really well but understod little of why or how to explain it.

So they stencilled those blasted markings on the foil box (more wind-less wind :(  ) and got busy selling them things.

Rant over,sorry...

The problem is that this type of advice can easily (and often does) set you off by 3-6 inches (in a game where cm.s matter) on front wing sweep alone.  It is all dependent on the entirety of the rig and having an incorrect reference as a beginner can set you way back. 

bigmtn

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Re: Foot placement over mast.
« Reply #10 on: February 14, 2023, 04:48:38 PM »
Unlike the Naish board, the new Kalama requires the Axis mast plate to be all the way forward for equal foot pressure. I'm using a single extra-long front foot strap set all the way forward.

Strap all the way forward? try moving front strap back, you're on a SUP you should have room to play around a bit. bring your front foot closer to foil if you can't bring foil closer to front foot

Badger

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Re: Foot placement over mast.
« Reply #11 on: February 16, 2023, 04:13:05 AM »
Unlike the Naish board, the new Kalama requires the Axis mast plate to be all the way forward for equal foot pressure. I'm using a single extra-long front foot strap set all the way forward.

Strap all the way forward? try moving front strap back, you're on a SUP you should have room to play around a bit. bring your front foot closer to foil if you can't bring foil closer to front foot

I'll definitely try that but might end up having to bring my rear foot forward as well to stay centered over the foil. Hopefully, I can get out for a test on Sunday.

I'm considering drilling out the Axis base plate if necessary to give me an extra inch in the tracks. It seems easy enough to do since the threaded holes are already there. What are those threaded holes for anyway? Does anyone know?




Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

Beasho

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Re: Foot placement over mast.
« Reply #12 on: February 16, 2023, 08:51:20 AM »
I can't tell whether you are all in agreement or disagreement at this point.

BUT that eCalc website is awesome and it helped define a few things.

1st off - The Aerodynamic Center of lift is at the 1/4 chord, or 25% back from the leading edge.  Google it.  No ambiguity.  I think Adriaan Roper once said it was at the 1/3 chord, BUT this is where the rule of thumb(s) start.

I replicated the design of my new favorite Axis 1300 wing (this is probably worth another post) and it calculates the CG should be 5.3 cm back from the leading edge with an 18 cm root chord.  This DOES work out to ~ 1/3  :o but this is because of the wing sweep.  The 1/4 chord point moves steadily back as the wing sweeps making the AVERAGE 1/4 chord further back from the dead center leading edge of the wing.  Hence why this software is great. Add some downforce from the tail and this would move the requisite CG forward.  But likely between 0 cm (leading edge of foil) and 5 cm.  ~ 2 inches of play.

That would be the center of the stance.  Go WIDE for beginner (maybe 26" or 13" forward, 13" back) and narrower for expert or downwind.   
« Last Edit: February 16, 2023, 08:53:35 AM by Beasho »

Califoilia

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Re: Foot placement over mast.
« Reply #13 on: February 16, 2023, 09:17:50 AM »
I'm considering drilling out the Axis base plate if necessary to give me an extra inch in the tracks. It seems easy enough to do since the threaded holes are already there. What are those threaded holes for anyway? Does anyone know?
I never did ask why they were threaded (which never made any sense to me either), but I did receive a new baseplate a few months back, and was happy to see that the holes were no longer threaded, and that an 8mm bolt slipped right on through.

Me: 6'1"/185...(2) 5'1" Kings Foil/Wing Boards...7'10 Kings DW Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

Badger

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Re: Foot placement over mast.
« Reply #14 on: February 16, 2023, 07:49:09 PM »
I can't tell whether you are all in agreement or disagreement at this point.

BUT that eCalc website is awesome and it helped define a few things.

1st off - The Aerodynamic Center of lift is at the 1/4 chord, or 25% back from the leading edge.  Google it.  No ambiguity.  I think Adriaan Roper once said it was at the 1/3 chord, BUT this is where the rule of thumb(s) start.

I replicated the design of my new favorite Axis 1300 wing (this is probably worth another post) and it calculates the CG should be 5.3 cm back from the leading edge with an 18 cm root chord.  This DOES work out to ~ 1/3  :o but this is because of the wing sweep.  The 1/4 chord point moves steadily back as the wing sweeps making the AVERAGE 1/4 chord further back from the dead center leading edge of the wing.  Hence why this software is great. Add some downforce from the tail and this would move the requisite CG forward.  But likely between 0 cm (leading edge of foil) and 5 cm.  ~ 2 inches of play.

That would be the center of the stance.  Go WIDE for beginner (maybe 26" or 13" forward, 13" back) and narrower for expert or downwind.

Do you mean CG or CL?

My stance is comfortable around 24". With the mast all the way forward in the tracks, measuring back from the Aerodynamic Center of Lift (25% of the chord from the leading edge of the foil), centering my stance places my front foot perfectly in the front foot strap and my rear foot directly over the mast. In theory, I should be well-balanced. If not, I'll just use the other base plate holes and bring the mast a bit more forward.


Kalama E3 6'1 x 23" 105L
Axis HPS 980 / PNG 1300
Sunova Flow  8'10 X 31"  119L
Me - 6'0" - 165lbs - 66yo

 


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