Distance from Foil to Mast foot

I tried the most back position possible with JP 150 foil board at 100cm and it felt nice with the 8.6 severne overdrive.
Much better than in middle position. Earlier lift and good control.
The 85cm from Balz is for his very small board and sail. But the note to try moving it back is good.

Rather than one specific location, perhaps the NEED should be considered.
Track forwards should be more stable and slower to fly.
Track back is more responsive and quicker earlier flight
What does the sailor need?

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tbwonder said..
I got my original setup information from the Slingshot Foil Academy. The suggestion is that the sweet spot is 43" (109cm) from the front Tuttle screw to the centre of the mast foot. Now I see in the Balz Muller video he is suggesting that 85cm is the place to be! This is a huge difference. Just wondering what distance are you finding to be the sweet spot and with what size sail. I am currently at 104cm with a 6.5m sail and about 101cm with 5.5m using the Slingshot Ghost Whisperer 101 foil

I think what Balz is trying to point out, is not to go by the exact measurements that he mentioned, but more the balance of the foot pressure on the board and just making a point of thinking about getting a lot of lift out of the foil and in the same time control it. Mostly with your front foot.

So in general it is better to go for more front foot pressure, than back foot pressure.
Maybe even the total opposite ratio of front and back foot pressure, compared to normal windsurfing?

The front foot pressure ensure you are more 'on top of the gear' and control is better.
If you need more lift / or if the wind drops, then you have room to move back a bit to get more lift and if you hit a gust standing more upright and forward, then it is easier to sheet the sail out and have control and push the board down.

If you have a set up where a lot of back foot pressure is required (and also the need to have the sail raked more back), then from this position it can easily get more out of control. - Like Balz pointed out,,

Also I think it is important to point out that this style is aimed more towards the freeride / wave / freestyle / cruising foils

For full race set up with faster foils / narrower wings and much wider boards with straps near the rails + big rigs, it is all a slightly different story,,

Tbwonder: I do have the Slingshot Ghost Whisperer 101 as well on my 125 Wizard board. It'is such a easy and slippery set up,,
Compared to the Hoverglide setup 76cm infinity wing, that I also use a lot (that I normally run in the middle of the track with a 5.9 / 5.3), I do run the Ghost Whisperer another 4-5 cm back. Not sure of the measurement, as I do all this trimming by feeling. If I go smaller sail sizes then approx 1-2cm further back again.

Don't get 'trapped' in the numbers to much as we all have different foils / rigs / boards / weight etc.
But yes, it is indeed a good tip to go back in the track until you get the balance right, whatever that measurement is.

The foil Balz is using on the video is the same as the Slingshot Ghost Whisperer 101 carbon by the way,,

It will definitely be variable, but you need a starting point. I have noticed that the combination of (1) front wing at the midpoint between front and rear feet (footstraps), and (2) 44" (inches) from the foil mast leading edge to the sail mast base position, gets you a good starting point. You adjust from there. That is for a 6.4 sail. For a bigger sail, go further back, for smaller, further forward. The point is to balance the mast base pressure, which is crazy critical for windfoiling.

I made this youtube 16 months ago. The settings work as a good starting point.

Well my set up is totally different. I had not measured it I just went off what felt right and gave me 50/50 leg pressure. Reading this thread made me get the tape measure out. So the stats are.
Board is a 7'8" Smik sup I had converted to a sup/windfoil board.
The foil is a cheap Chinese knock off ( I fattened up the front wing considerably.
The board has tracks and for sup surfing I ride it all the way forward. My first sail I put the foil all the way back. This was horrible as to fly I had 90%back leg pressure. After 4 sessions I now windfoil with the foil in the same positson as sup surfing. It measures 80cm from the centre of the mast to dead centre of the mast track. I usually run it all the way back. Got any tips for a newbie to foiling. I am unable to line up the leading edge of the foil with the mid point between the straps but it works ok

I ride my mastfoot at 82.5cm (most backward position for me, my foilboards' 25cm track ends where the one in my slalomboard begins haha) currently with most sails, independent of foil (Lok? LK1 Race, or F-One Levo Freeride), the Lok? is quite front foot powered (more frontfoot than Starboard GT for ex.), the F-One a little backfoot on a normal slalomboard. I recently recieved a proto which has the backmost position a pinch further forward than Im used to, but I asked for the track to be moved back in the next version for it feels stretched and am gonna hopefully try a track starting at 75cm soon. Have to say I ride single backstrap right on top of the tuttle (so also a little further back than Balz), and my strap spacing at 38cm (normal is 42). Very compact, very nice for pumping / flying early / jibing / downwind and upwind 360s etc. Max sailsize 4.9 from about 10kts up, down to 3.0 and recently even 2.5m2.

I rode a Slingshot on Tenerife and felt personally the "adviced" setup is too backfooted, I like more front foot power. (I can fly balanced on both feet with my front foot about 20cm in front of the front strap and the backfoot halfway between the straps)

I spoke with Balz 2 years ago when we were both designing our own foilboards and exchanged settings with him, at that time he had his backfoot further back aswell, makes me wonder whether the current position is due to construction problems (we ran into those) or because he likes it a little further forward / maybe closer to the frontstrap. He said he liked his frontstraps where they were, only 20cm behind the masttrack.

When racing I have the mastfoot further forward, between 105 - 111 cm, depending on wind, using 8.6 freerace or 9.9 foilrace sails on a formula, but I keep the straps in the backmost positions and quite narrow.

i put the bigger sails further forward, otherwise the stance feels funky (harness lines over the backstrap hahaha). This does mean I compensate by using my most powerful foil with a lot of rake on the stab to max out power.

p.s. Got a little heavier with 88kg's all muscle for my 192cm length ;).

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Bender said..

Paducah said..
What's your stab angle? What size sails are you using?

My stab is level. I use 4.7, 5.3 and 5.8m wave sails

So... 0 degree angle to the wing? Sorry if my question seems repetitive, I want to make sure I understand correctly before launching unnecessarily into something.

There is a way to measure the stab angle with respect to the front wing:

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Paducah said..

Bender said..

Paducah said..

Bender said..

Paducah said..
What's your stab angle? What size sails are you using?

My stab is level. I use 4.7, 5.3 and 5.8m wave sails

So... 0 degree angle to the wing? Sorry if my question seems repetitive, I want to make sure I understand correctly before launching unnecessarily into something.

yes

0 makes it more difficult for level and stable flight - even ignoring the front/back issue. I've measure several prodution foils and they seem to be around 2.5 degrees (up elevator ie front edge pointing down) and my Starboard GT was more (may not have been accurate).

Read this thread why neg stab angle is necessary for stable flight both on airplanes and foils (look for CJW's comment): www.seabreeze.com.au/forums/Windsurfing/Foiling/Does-a-longer-fuselage-make-a-more-stable-ride-?page=1#13

or get google to translate this glissattitude article for you if your French is like mine:
marseille.glissattitude.com/blog/windfoil-calage-des-stabs-en-foil.html

Thanks to segler for posting that video so I don't have to dig it up. Many cell phones can be used as a digital level with free/cheap apps, btw. No need to spend money on one.

Thanks a bucket load for that info.It makes a lot of sense. I will have a play with some washers tonight

...I'm not a fan of modifying the stab angle. I creates drag at higher speed. The video did provide some nice insights on measuring stab angles; but wouldn't getting better technique compensate for all that? I guess I'll be swimming like the dolphins.

Thanks for the help. I used a free level app on my phone. With two washers the stab angle is 2.5deg now. Looking forward to testing it out tomorrow
I will leave all the other settings as is and see what difference it has made. Once again thanks for the advice
I'm still very new to foiling. Cheers Bender

Looks like the foil mast could be longer than the board

Bruce Peterson (Sailworks) and I measured stab angles for several production windfoils. 2 to 3 degrees down angle is typical. Some foils (LP and NP and others) actually let you adjust this. When all is said and done, it is still 2 to 3 degrees down angle that works.

The stab, by pushing DOWN, functions to lift the board and rig in front of the front wing, which acts as a big fulcrum.