Used to use a two bolt mast base, but early on in foiling became convinced that I needed base farther back on a Goya Bolt 135, so got a one bolt base and have it as far back as mast track will allow, 42-5/8" (108 cm) from center of one bolt mast base to center of front DT box screw. Two bolt mast base is 1-1/4" (3 cm) farther forward when as far back as possible (111 cm from center of mast base to center of front DT screw). Going to try moving single bolt base 1-1/4" (3 cm) forward next time to see how it affects foil, because I am now wondering if with all I have leaned if I still need single bolt mast base all the way back. Would rather use two bolt base.

Assumption is that moving mast base forward will make it harder to get up on foil, will see, but wondering if anyone else who is experienced has done this experiment.

I have been doing these experiments since 2017 with an old formula board that I have marked up (it's now pretty ugly). Beginning in the old days of formula racing, we all stopped using 2-bolt bases because they did not offer enough fore and aft movement. We all went to one-bolt bases. I have never gone back.

For me the magic number is sail mast base center at 42" in front of the front fin screw head (deep tuttle mount). Tweak from there. All the riders at Sailworks use this starting number as well. The range ends up being 41"-44" depending on sail size/weight, footstrap positions, and front wing position.

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segler said..
I have been doing these experiments since 2017 with an old formula board that I have marked up (it's now pretty ugly). Beginning in the old days of formula racing, we all stopped using 2-bolt bases because they did not offer enough fore and aft movement. We all went to one-bolt bases. I have never gone back.

For me the magic number is sail mast base center at 42" in front of the front fin screw head (deep tuttle mount). Tweak from there. All the riders at Sailworks use this starting number as well. The range ends up being 41"-44" depending on sail size/weight, footstrap positions, and front wing position.

Got it, thanks segler, will have to try, two bolt base will keep me within 44", ~43-7/8" at the minimum. I used the two bolt base for foiling, and got up, but there were other factors affecting lift at the time including a foil with wing and stab. that were out of alignment with each other and not at 90 degrees to mast.

I think there are many major (dominant) factors that affect mast base placement for foiling and the placement will vary greatly even for one sailor:
1) Sail size (MBP)
2) Sail weight (MBP)
3) Sailor Weight
4) specific Front Wing position (that you stand over) you are using at the time
5) footstraps position
6) Are you in winds closer to 100% foiling or 50%/50% Slogging ?
7) Board type (weight/volume distribution)

So for example for "Heavy Dude" going with larger sails in relatively lighter winds the double bolt quick disconnect chinook plate goes max aft (for max lift) therefore distances (between center of chinook plate and center of first foil mast screw) for my boards I use for foiling look like this:
Exocet RF91 (155L) 113.5cm
SB Go 200 113.5cm
SB FW167 (182L) 109.5cm
Exocet RF81 109.5cm
SB Go 180 109.0cm
SB Race 100 107.5cm
SB Race 100 (mod) 99.0cm (See the Note 1)
Slingshot Flyer 280 85.0cm

Note 1: For picture what Modified Chinook Plate Extender (moving MB aft beyond track) looks like, check:
www.seabreeze.com.au/forums/Windsurfing/Foiling/Impressions-of-new-Windfoil-boards-for-super-heavyweights#2809771

Interestingly enough, when you have much more lightweight person going with much smaller sails in stronger winds like Darius L (Racing in Winduro 2019), on the same SB FW167 Board, He moves the plate max forward and actually uses the Modified Chinook Plate Extender Forward !
BTW: Darius made curvature to support to the bottom of the board. Like in the picture below from 2019 Winduro.
I actually shaped (shaved off) thick plywood piece to remove that curvature to use that Mod on SB Race 100 (see in the link above) for the area of flat surface on the board.

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mareks360 said..
I think there are many major (dominant) factors that affect mast base placement for foiling and the placement will vary greatly even for one sailor:
1) Sail size (MBP)
2) Sail weight (MBP)
3) Sailor Weight
4) specific Front Wing position (that you stand over) you are using at the time
5) footstraps position
6) Are you in winds closer to 100% foiling or 50%/50% Slogging ?
7) Board type (weight/volume distribution)

So for example for "Heavy Dude" going with larger sails in relatively lighter winds the double bolt quick disconnect chinook plate goes max aft (for max lift) therefore distances (between center of chinook plate and center of first foil mast screw) for my boards I use for foiling look like this:
Exocet RF91 (155L) 113.5cm
SB Go 200 113.5cm
SB FW167 (182L) 109.5cm
Exocet RF81 109.5cm
SB Go 180 109.0cm
SB Race 100 107.5cm
SB Race 100 (mod) 99.0cm (See the Note 1)
Slingshot Flyer 280 85.0cm

Note 1: For picture what Modified Chinook Plate Extender (moving MB aft beyond track) looks like, check:
www.seabreeze.com.au/forums/Windsurfing/Foiling/Impressions-of-new-Windfoil-boards-for-super-heavyweights#2809771

Interestingly enough, when you have much more lightweight person going with much smaller sails in stronger winds like Darius L (Racing in Winduro 2019), on the same SB FW167 Board, He moves the plate max forward and actually uses the Modified Chinook Plate Extender Forward !
BTW: Darius made curvature to support to the bottom of the board. Like in the picture below from 2019 Winduro.
I actually shaped (shaved off) thick plywood piece to remove that curvature to use that Mod on SB Race 100 (see in the link above) for the area of flat surface on the board.

Man I like that mast base adapter mareks!, what material did you make it out of?, I see the black top layer and tan bottom layer. Would really like to move mast base farther back and have a two bolt base to use with an adapter, only want maybe 3-4 cm of extension.

With my two bolt Streamlined base and an adapter, I could move mast 2-1/2 cm further aft, which would be perfect. That is with one screw on the adapter and the forward mast base screw going through the mast base and adapter (just need to replace the forward screw with a longer screw to go through adapter).

I can get a piece of starboard to make an adapter from, but do not know if it would be strong enough. I can get scrap 3/4" thick starboard, guessing it should be strong enough on that short of a section.

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Sandman1221 said..

Man I like that mast base adapter mareks!, what material did you make it out of?, I see the black top layer and tan bottom layer. Would really like to move mast base farther back and have a two bolt base to use with an adapter, only want maybe 3-4 cm of extension.

With my two bolt Streamlined base and an adapter, I could move mast 2-1/2 cm further aft, which would be perfect. That is with one screw on the adapter and the forward mast base screw going through the mast base and adapter (just need to replace the forward screw with a longer screw to go through adapter).

I can get a piece of starboard to make an adapter from, but do not know if it would be strong enough. I can get scrap 3/4" thick starboard, guessing it should be strong enough on that short of a section.

Original Mod comes from Darius L. The material seems to be similar to what the chinook plate is from. I added the plywood to make it usable on SB Race 100 also at full surface contact (while still could use it on SB FW 167L).


Next version for the SB Race 100 "My Mod Chinook double bolt quick release extension plate" will be thinner and made of bottom plywood and top stainless steel plate (next phase 2).
Here is what I am thinking. Just need to get larger stainless plate.
I am lucky because Tacoma Screw Store is like less than 2 miles away and they pretty much have any bolt I wished with exact length I needed. No need to cut it. Sweet!




BTW: If you want single bolt base and get extra few cm, there used to be Chinook asymmetrical base. I bought one like 20 years ago.
Not sure if anybody manufactures anything like this anymore.
I am so happy with Double bolt Chinook Quick Disconnect plates and their reliability that, as I said, all my boards now have them.
Also all my UJs have hex (Allen) key in the pin so no need to carry any separate hex key for adjustments.
That is another brilliant solution.



Now if you wonder how much Extension am I getting ?
Have a look.
Another brilliance of this solution is that original hole of chinook plate is still holding on to the track, just with a longer bolt.
I only marked the board with black pen so I know where it is still safe to tighten the bolt (max aft position).



For people who have perfect wind conditions for 100% foiling or want to wait until "white caps" appear, stock gear may work well.
For those of outside above categories, also for "heavier weights" - "life will find a way" - have to be Innovative / Creative.

Huge thanks mareks for a great idea and design!, just made a mast base aft extension out of 3/4" starboard for my two bolt Streamlined mast base which elevates mast base so it will not hit Goya Bolt concave deck ridge AND extends mast track aft 2-1/2 cm compared to a single bolt base! I always wanted to know what that would do for balancing the foil. Andy Brandt did comment he had to be standing all the way back with both feet when doing foiling gybes on my kit (though he weights a good bit less than me), will see what 2-1/2 cm does, hopefully will be too much, so I can move it forward some. Scrap starboard cost $7 from marine surplus (can make more if needed) and needed a SS Nylox nut for rear screw at $1.39, had the other screws.

Now it just occurred to me that I could use a longer piece of starboard, and bolt the mast base to the starboard, and then have two screws going through just starboard with both anchoring into mast track (with neither going through base). Starboard is pretty strong, but I like having one bolt going through mast base and attaching to mast track. Will have to see how the foil balances with mast base 2-1/2 cm more aft first.

I am always glad when I can help fellow Windsurfers/Windfoilers directly or indirectly.
Often it is not about exactly the same solution but often about "food for thoughts".
Or sharing what works for you, what conditions and how - then someone can take it to the next level.
Everyone gains having another "tool" available and tested for the "toolbox".

First impression of the Goya Bolt and AFS W95 foil with the mast base extended 2 cm aft, the board came up on foil more easily without having to deliberately use rear foot pressure, and when on foil it felt like the wing was right between my feet (which it always was) but now I had this solid feeling of being on top of the wing. Also, when the wind dropped did not have to be back footed to stay up, though was still going slow of course. So now the question is what if I moved it back farther?, because it is not back too far right now "I think". Will get out on it more first, really want to see/feel what it does for my foiling gybe, still only doing them on flat water for now, so need winds out of the North.

So what does it feel like when you move the mast base too far back? segler guessing you have done that.

Center of mast base is 41-3/4" (106 cm) to center of front DT screw, so just under 42" which was the magic number for segler.

And then I realized I could switch out the mast base extender front M6 bolt, that goes through just the starboard, with an M8 bolt and bolt both Streamlined mast base bolts to the starboard, then I could move the mast base aft another 2-1/2" (6 cm), that would get me to 39 inches (99 cm). And could always go back to using two bolts on the mast base extender. Then I could stick with the mast base extender that I have already made. Only question is if the starboard is strong enough, but will have only 1-1/2" between front edge of Streamlined mast base and M8 mast track bolt, and the starboard is 3/4" thick so thinking I should be good.

Okay, had a little more room, moved mast base back 1/4", so now at 41-1/2" mast base to front DT screw, forecasted to have N winds today, will see if I get out and how it affects foiling gybe.

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Sandman1221 said..
Only question is if the starboard is strong enough.

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WillyWind said..

Sandman1221 said..
Only question is if the starboard is strong enough.

That is a beauty WillyWind! How thick is the aluminum or is it stainless steel?, and how much metal did you have to remove to recess the M8 bolt on the bottom?

Of course, I needed a 3/4" spacer so the starboard did that, plus starboard is corrosion proof, just saying

Here are pics of mine bottom and top, had to jam in a steel pick to keep Nylox nut from turning when tightening screw on topside. And want to make sure the Nylox nut and screw end are both completely recessed, otherwise will get pressed into board deck.

Okay, called around, Bruce at Sailworks is very familiar with AFS foils and said if I move the sail mast base too far back I will become front footed because nose of board will want to go up. So I was not there yesterday, will see what an extra 1/4" aft does, before turning mast base extender into a single bolt extender to get an extra 2" of aft extension, which should put me past the balance point.

I love this "Internet On-line Age" for couple of things. Obviously, Forums like Seabreeze.com.au for knowledge sharing.
But also for some on-line Companies.
Can you imagine. I ordered Custom size Stainless Steel Plate on-line. past 6pm Thursday. Got order confirmed be e-mail at 10pm.
2 Plates were cut and shipped on Friday (next day). UPS delivered today (Saturday) just afternoon.
The Company website is: OnlineMetals.com
Yes, they are in Seattle WA, USA. Not sure if you have any similar Service in Europe and "Down Under".
You go online select the material (steel, aluminum, any metal, even plastic). then you select the shape.
Then you select the size. Standard size is e.g. 12"*12" and many others
BUT there is also an option for "Custom" order:
So I entered exactly the dimensions for my plate: 7.75" * 4.75" and you get the price. In my case for $34.20 a piece for 0.075" Stainless Sheet 316/316L Cold Roll 2B.
Only need to cut/grind to round the edges for my desired shape and drill holes.
Here is the picture:




The idea to use this Company does not come from me. It comes from my Freind, Darius L, he made the original plate for his SB FW 100.5 167L Board. I bought from him board with the plate that had holes for Slingshot M10 bolts.
When I wanted to have 2nd plate just for M6 bolts for Power Plate and Starboard Masts, I ordered another 2 plates from them.
I still use with the Power Plate mostly.
Here is the picture:

Nice mareks, thanks for the online shop. And I realized a single bolt mast base extender could get rotated by an offset mast base. So decided to make a second two bolt mast base extender from starboard, with both Streamlined mast base bolts attached just to the starboard. This one gives me 3.5 more inches of aft extension compared to a single bolt base. I want to move the mast base aft until I feel board nose want to lift, and then adjust forward till balanced.

I was out today in 8-9 knots average and was getting up pretty easily with an 8.0 sail and 490 mast on AFS F1080 cm2 wing, but was a little back-footed going into the gybes (but better than with a single bolt base), will have to see if more aft extension reduces the back foot pressure in light winds.

When I first started foiling I asked Bruno at AFS how far his mast base was from the DT box, he said 41"/104 cm from front DT box screw to "middle" of foil board mast track, that was for an AFS foil and AFS foil board. With my new mast base extender the most aft position is at 39.5"/100.5 cm to front DT screw, will see today if that position makes board nose want to lift and makes me front footed.

Now in 18-30 knots with the S670 cm2 wing and 4.5 Phantom, I had the single bolt mast base all the way back at 42-7/8"/109 cm and that was good because I was not noticeably front footed and the foil did not want to breach. But in 8-10 knots with F1080 cm2 wing and 8.0 Freespeed I am back-footed most of the time at 42-7/8", and when I used 1st mast base extender to move mast base back to 41-7/8" definitely was less back-footed and got up easier, so will be interesting to see how moving mast base back even further affects back foot pressure and foiling gybes in 8-10 knots. In 10-15 knots I use F1080 and F770 cm2 wings 7.2 and 5.8 Freespeeds, and then I am back footed on the low end of the wind range for the 4 different wing/sail combinations and that reduces when I can go into a gybe balanced or front-footed. Hopefully with the new mast base extender I be more balanced or front footed, without increasing risk of breaching.

The big question is will the 3/4" starboard mast extender hold up to sail mast foot pressure, only one way to find out! But thinking I will see stress lines in starboard before it breaks.

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Sandman1221 said..
The big question is will the 3/4" starboard mast extender hold up to sail mast foot pressure, only one way to find out! But thinking I will see stress lines in starboard before it breaks.

Here is what I am thinking about it:
If it was just Windsurfing, the most pressure would be downward (MBP) and that is why in my solutions I make sure that the extender sits properly flush on the board with full contact -meaning no stress on extender material nor board nor bolts.
Also using M8 bolts eliminates any force concerns in my case.
Second force in Windsurfing is forward but that is not a problem using 2 bolt attachment.
Sideway rotation forces is not an issue when even the original plate is so wide (e.g. from chinook).

Therefore the only concern from my side for starboard material is when you fall in the water holding to the boom while the boards hydrofoil may act as the anchor holding it the other way.
I think there is no way of telling. I do not know the starboard material, you are using, bending/breaking properties.
Using stainless steel (on top of plywood or other material) would at worst only bend it but not break it.

So my thoughts are:
a) M8 bolts give you more strength than M6
b) 3 bolt solution where one still goes through the original plate to the board has more strength (unlike 4 bolt longer extender)
c) if 4 bolt extender, you do not want to use neither stainless steel nor aluminum, can you somehow use a leash like we use for hydrofoil ?
Or alternatively use the webbing ribbon going between second and third bolt (suspected breaking point).
I am talking about the same type of ribbon used in Chinook Hourglass UJs like on my Chinook asymmetrical - picture I provided earlier.

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mareks360 said..

Sandman1221 said..
The big question is will the 3/4" starboard mast extender hold up to sail mast foot pressure, only one way to find out! But thinking I will see stress lines in starboard before it breaks.

Here is what I am thinking about it:
If it was just Windsurfing, the most pressure would be downward (MBP) and that is why in my solutions I make sure that the extender sits properly flush on the board with full contact -meaning no stress on extender material nor board nor bolts.
Also using M8 bolts eliminates any force concerns in my case.
Second force in Windsurfing is forward but that is not a problem using 2 bolt attachment.
Sideway rotation forces is not an issue when even the original plate is so wide (e.g. from chinook).

Therefore the only concern from my side for starboard material is when you fall in the water holding to the boom while the boards hydrofoil may act as the anchor holding it the other way.
I think there is no way of telling. I do not know the starboard material, you are using, bending/breaking properties.
Using stainless steel (on top of plywood or other material) would at worst only bend it but not break it.

So my thoughts are:
a) M8 bolts give you more strength than M6
b) 3 bolt solution where one still goes through the original plate to the board has more strength (unlike 4 bolt longer extender)
c) if 4 bolt extender, you do not want to use neither stainless steel nor aluminum, can you somehow use a leash like we use for hydrofoil ?
Or alternatively use the webbing ribbon going between second and third bolt (suspected breaking point).
I am talking about the same type of ribbon used in Chinook Hourglass UJs like on my Chinook asymmetrical - picture I provided earlier.

Thanks mareks, the starboard is high density polyethylene, like what is used in cutting boards in the kitchen. Did a catapult today when mast base was all the way aft at 39.5" and the mast base extension looked good, no obvious stress lines.

From Wikipedia
HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE.[7] The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures (120 ?C/248 ?F for short periods).

So got out today on Goya Bolt 135 (2019 model year) purposely under-sailed on a 5.8 Freespeed and AFS W95 F1080 cm2 wing with the two bolt mast base extender, set it as far aft as possible so 39.5"/ 100.5 cm from mast base to front DT box screw. What I noticed right away while on the water in waves is the nose of the board started lift when I loaded up the sail, got up easily, but could feel the kit was very sensitive to gusts, also I did not need to have my rear foot so far back. Was just too touchy, so moved mast base 1" forward to 40.5" and then it felt good, board stayed level while I pumped it up, back foot was still farther forward which was good, and in-flight it was easier to maintain a level flight through gusts and lulls, especially the lulls when normally I would come down (unless I pumped the sail or foil) but now stayed up going slowly of course!, really surprised by that. Did have a catapult when it was initially all the way back, and starboard looks fine, so I think it will be okay for this purpose, it can bend a certain amount without cracking.

So single bolt mast base was 42-7/8" from front DT box screw when all the way back, while two bolt extender mast base at 40-1/2" was good for todays conditions. So mast track would be better for foiling if it was 2-1/4" further aft. Now I have been using the Bolt for almost 4 years with a single bolt mast base, and it has been good, but on gusty days it can get tiring to keep a level flight. Today was 3rd day in a row foiling, and while I was assisted by two cups of expresso, it was a much more relaxing and less fatiguing session!

Select to expand quote

Sandman1221 said..

mareks360 said..

Sandman1221 said..
The big question is will the 3/4" starboard mast extender hold up to sail mast foot pressure, only one way to find out! But thinking I will see stress lines in starboard before it breaks.

Here is what I am thinking about it:
If it was just Windsurfing, the most pressure would be downward (MBP) and that is why in my solutions I make sure that the extender sits properly flush on the board with full contact -meaning no stress on extender material nor board nor bolts.
Also using M8 bolts eliminates any force concerns in my case.
Second force in Windsurfing is forward but that is not a problem using 2 bolt attachment.
Sideway rotation forces is not an issue when even the original plate is so wide (e.g. from chinook).

Therefore the only concern from my side for starboard material is when you fall in the water holding to the boom while the boards hydrofoil may act as the anchor holding it the other way.
I think there is no way of telling. I do not know the starboard material, you are using, bending/breaking properties.
Using stainless steel (on top of plywood or other material) would at worst only bend it but not break it.

So my thoughts are:
a) M8 bolts give you more strength than M6
b) 3 bolt solution where one still goes through the original plate to the board has more strength (unlike 4 bolt longer extender)
c) if 4 bolt extender, you do not want to use neither stainless steel nor aluminum, can you somehow use a leash like we use for hydrofoil ?
Or alternatively use the webbing ribbon going between second and third bolt (suspected breaking point).
I am talking about the same type of ribbon used in Chinook Hourglass UJs like on my Chinook asymmetrical - picture I provided earlier.

Thanks mareks, the starboard is high density polyethylene, like what is used in cutting boards in the kitchen. Did a catapult today when mast base was all the way aft at 39.5" and the mast base extension looked good, no obvious stress lines.

From Wikipedia
HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE.[7] The difference in strength exceeds the difference in density, giving HDPE a higher specific strength. It is also harder and more opaque and can withstand somewhat higher temperatures (120 ?C/248 ?F for short periods).

Here is a breakdown of the tensile strengths of some common woods:
Oak has a tensile strength of 9,000 psi (~62 MPa), making it a great choice for projects that need a lot of strength and durability.
Birch has a lower tensile strength of only 4,000 psi but is still a strong choice for many projects.
Alder has a tensile strength of 4,000 psi and is a great choice for projects that need a lot of strength like tables, cabinets and bookcases.
Cherry is a very hard wood, with a tensile strength of 2,000-7,000 psi.
Walnut has a tensile strength of 1,500-4,000 psi.

So starboard/HDPE with a tensile strength of 38 MPa, is stronger than all of the above woods, with a Cherry average psi of 4.5 psi, except oak.

Probably should of checked that information out before building the mast base extender

Also remember that you can get the nose down by angling the windward rail down.
typically need a wide board setup to do this not so sure how easy that is for a carving design

and an alternative to getting the mast base back would be to mount the front wing further forward..? No adapters needed then A few thoughts in the video below. Maybe not all for this topic but it might help. Speed needs control.
SPEEEED - How to WindFoil - Fast !

Select to expand quote

berowne said..
Also remember that you can get the nose down by angling the windward rail down.
typically need a wide board setup to do this not so sure how easy that is for a carving design

and an alternative to getting the mast base back would be to mount the front wing further forward..? No adapters needed then A few thoughts in the video below. Maybe not all for this topic but it might help. Speed needs control.
SPEEEED - How to WindFoil - Fast !

Thanks berowne, great video!

And I would add as your speed increases the mast base needs to move forward to offset the increased lift by the foil, Bruce from Sailworks told me that, and I am now experiencing it with the ability to move my mast base more aft. I know in 18-30 knots with an AFS S670 cm2 wing and Phantom 4.5 sail the kit is perfectly balanced with a single bolt mast base all the way back in the factory track at 42-3/4" with no foiling out and pretty equal foot pressure, but in 12-14 knots with an AFS F1080 cm2 wing and Freespeed 5.8 sail the kit is perfectly balanced at 40-1/2" using the mast base extender. So that is a big difference in mast base position! (2-1/4") and something I could never of tested without the 3-1/2" aft mast base extender. I think the biggest improvement will be in foiling in light winds, because it was easier getting up, maintaining a level flight, and staying up in lulls, in 12-14 knots at 40-1/2".

Question is in 8-10 knots where should the mast base be, know with the first shorter mast base extender I made (see above) that at 41-3/4" with an AFS F1080 cm2 wing and Freespeed 8.0 sail with 490 mast I was getting up with some pumping in 8-10 knots and having long stable flights, while a guy who weights the same and on a foil board with an i84 wing and 6.0 sail could not get up!, the i84 wing is almost double the surface area of the F1080 wing. Looking forward to reducing my light wind minimum, cause I do live in an area where the year round average wind speed is 8.7 knots.

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Sandman1221 said..

Question is in 8-10 knots where should the mast base be, know with the first shorter mast base extender I made (see above) that at 41-3/4" with an AFS F1080 cm2 wing and Freespeed 8.0 sail with 490 mast I was getting up with some pumping in 8-10 knots and having long stable flights, while a guy who weights the same and on a foil board with an i84 wing and 6.0 sail could not get up!, the i84 wing is almost double the surface area of the F1080 wing. Looking forward to reducing my light wind minimum, cause I do live in an area where the year round average wind speed is 8.7 knots.

In my pursue of lightest wind windfoiling, the "Eureka moment" came in 2020 after watching first 2 minutes of Tiesda You (Starboard) with Britt (NB Windsurfing Florida) introduction to Supercruiser video.
He explains that there are 2 Types of Windfoiling:
a) large foils, smaller sails, up right, (often even no harness needed) - going directly from slogging to full foiling
b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !) going from slogging through planing first then full foiling.
Interestingly enough, he was mentioning minimum wind for both at around 6kt of wind.



Since then I worked a lot on pushing the boundaries for "Heavy Dude" in "Light Winds" (5-10mph or 4-9kt) but I mentioned it in another Topic on Seabreeze and provided extra links:
www.seabreeze.com.au/forums/Windsurfing/Foiling/Impressions-of-new-Windfoil-boards-for-super-heavyweights#2809771

Select to expand quote

berowne said..
Also remember that you can get the nose down by angling the windward rail down.
typically need a wide board setup to do this not so sure how easy that is for a carving design

and an alternative to getting the mast base back would be to mount the front wing further forward..? No adapters needed then A few thoughts in the video below. Maybe not all for this topic but it might help. Speed needs control.
SPEEEED - How to WindFoil - Fast !

Berowne,
Your Video and also your post about Working towards (and breaking) 30kt speed on windfoil is Absolutely Outstanding !
Actually that is amazing that there is so much in common going for max speed with trying to get the earliest flights in the lightest winds.
Why ?
1) it is all about Efficiency,
2) That comes also from that we are still in the same category of windfoiling meaning:
b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !)

So the contradictions come when for example "Sam Ross" or "Riding along with Cookie" are talking about windfoiling and speed in the aspect of:
a) large foils, smaller sails, up right, (often even no harness needed)

Select to expand quote

mareks360 said..

berowne said..
Also remember that you can get the nose down by angling the windward rail down.
typically need a wide board setup to do this not so sure how easy that is for a carving design

and an alternative to getting the mast base back would be to mount the front wing further forward..? No adapters needed then A few thoughts in the video below. Maybe not all for this topic but it might help. Speed needs control.
SPEEEED - How to WindFoil - Fast !

Berowne,
Your Video and also your post about Working towards (and breaking) 30kt speed on windfoil is Absolutely Outstanding !
Actually that is amazing that there is so much in common going for max speed with trying to get the earliest flights in the lightest winds.
Why ?
1) it is all about Efficiency,
2) That comes also from that we are still in the same category of windfoiling meaning:
b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !)

So the contradictions come when for example "Sam Ross" or "Riding along with Cookie" are talking about windfoiling and speed in the aspect of:
a) large foils, smaller sails, up right, (often even no harness needed)

b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !)
a) large foils, smaller sails, up right, (often even no harness needed)

Mareks I actually mix b) and a) all in the same day on the same kit using one or more of my mid to higher aspect AFS wings (F1080, F770, S670 cm2) and usually the same sail.
a) hooked in leaning out with short forward harness lines to pull sail over while heading upwind or crosswind
b) when a lull comes I stand upright and head crosswind until next gust comes, and can also start pump the foil too unhooked standing upright when I am using F1080 wing.
c) on downwind runs I am unhooked and ripping while getting my lower body out over the water to balance the partially sheeted out sail.

Some people do try to simplify it, but does not hold true in my experience!

And just a heads up, the mast base extender does trap water against the board deck, so I remove it after each session. I also make sure the centerline on the extender is aligned with the board centerline, since with the mast-base offset from the two mounting screws it is easy to get the mast base off of the board centerline when tightening up the mast base extender screws.

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Sandman1221 said..

b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !)
a) large foils, smaller sails, up right, (often even no harness needed)

Mareks I actually mix b) and a) all in the same day on the same kit using one or more of my mid to higher aspect AFS wings (F1080, F770, S670 cm2) and usually the same sail.
a) hooked in leaning out with short forward harness lines to pull sail over while heading upwind or crosswind
b) when a lull comes I stand upright and head crosswind until next gust comes, and can also start pump the foil too unhooked standing upright when I am using F1080 wing.
c) on downwind runs I am unhooked and ripping while getting my lower body out over the water to balance the partially sheeted out sail.

Some people do try to simplify it, but does not hold true in my experience!

Sandman,
I do the same mix a) & b) even at the same time using 10.8m race sail rigged on 550cm 100% carbon mast using Starboard Race 100cm wide (208L) while the foil is the biggest shovel Slingshot Infinity i99 (2371cm2) but only if I expect wind to be in 5-10mph (4-9kt) main wind.
If more wind expected, I I would do more mileage on Starboard Race foil M1000/115+/255(-2), using other components unchanged.
I rather change foils than sails.
However, when discussing complex issues, there is a Wisdom:
"Divide (or separate) complex larger issues into smaller more distinct issues that can be well understood".
or
"Q: How to eat an elephant ? A: One bite at a time".

Was nice to exchange some thoughts with you !

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mareks360 said..

Sandman1221 said..

b) smaller foils (HA & highly efficient), larger sails, hanging out in the harness - (great if you like traditional windsurfing !)
a) large foils, smaller sails, up right, (often even no harness needed)

Mareks I actually mix b) and a) all in the same day on the same kit using one or more of my mid to higher aspect AFS wings (F1080, F770, S670 cm2) and usually the same sail.
a) hooked in leaning out with short forward harness lines to pull sail over while heading upwind or crosswind
b) when a lull comes I stand upright and head crosswind until next gust comes, and can also start pump the foil too unhooked standing upright when I am using F1080 wing.
c) on downwind runs I am unhooked and ripping while getting my lower body out over the water to balance the partially sheeted out sail.

Some people do try to simplify it, but does not hold true in my experience!

Sandman,
I do the same mix a) & b) even at the same time using 10.8m race sail rigged on 550cm 100% carbon mast using Starboard Race 100cm wide (208L) while the foil is the biggest shovel Slingshot Infinity i99 (2371cm2) but only if I expect wind to be in 5-10mph (4-9kt) main wind.
If more wind expected, I I would do more mileage on Starboard Race foil M1000/115+/255(-2), using other components unchanged.
I rather change foils than sails.
However, when discussing complex issues, there is a Wisdom:
"Divide (or separate) complex larger issues into smaller more distinct issues that can be well understood".
or
"Q: How to eat an elephant ? A: One bite at a time".

Was nice to exchange some thoughts with you !

Mareks,
Enjoyed exchanging ideas with you too, am so glad to have a mast base extender to test out more aft mast base positions, already seeing some good improvements in my foiling, and I owe that to your post!

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segler said..
For me the magic number is sail mast base center at 42" in front of the front fin screw head (deep tuttle mount). Tweak from there. All the riders at Sailworks use this starting number as well. The range ends up being 41"-44" depending on sail size/weight, footstrap positions, and front wing position.

Segler, did you and everyone else use mast base extenders to check outside of the range of the factory mast track? I ask because 40-1/2" was really good for my kit and conditions the other day (Goya Bolt 135, Freespeed 5.8 sail, AFS foil with F1080 wing and no stab. shim., in 12-14 knots). But on that day went from 39-1/2" (max aft position) which gave too much lift, to 40-1/2" which felt so good that I did not try adjusting it more. 40-1/2" is 2-1/4" farther aft than what I can get with a single bolt base in the factory mast track (42-3/4"). My measurements are from the center of mast base to center of DT box front screw.

You have an AFS foil so I am surprised you found 42" to be the sweet spot. For sure, with my AFS foil and S670 wing and 4.5 Phantom sail in 18-30 knots 42-3/4" seemed to be perfect in the past with even foot pressure and the foil not wanting to breach, though in retrospect maybe it did take a little too much effort to get off the water, but will revisit that now I have the mast base extender since I really will not know until I go too far aft and increase the lift too much. Not looking forward to trying that experiment in 18+ knots, but from the other day I should be able to tell on the water if it is too far aft from how the nose of the board behaves, i.e., when I power up the sail, if the nose of the board rises off the water while the rest of the board is still on the water, that tells me I have mast base too far back. In contrast, when the mast base position is good and I power up the sail on the water, the board lifts off the water evenly (excluding the effects of a passing wave of course). Obviously preliminary results from one day with the two bolt 3-1/2" aft mast base extender, so will have to see after more TOW.

And with the current design of the mast base extender, the max. forward position of the mast base is 41-3/4", can change that by moving the mast extender front track screw more aft, will have to see on a ~18+ knot day when I can use the S670 wing which was limited to a max. aft position of 42-3/4" in the past using the factory mast track and a single bolt mast base.

I bet now that your mastbase is in a more reasonable spot for foiling you won't have to do so much adjusting of the harness lines. With the base as far forward as you had it you'd really have to keep the boom way high and really rake the sail back for trim when flying, so lines which worked for blasting wouldn't work for slogging at all.

I like 40.5-41.25 for almost every sail in the quiver, except when really overpowered when I'll go as far as 42.5-43".