Wind picks up and you replace wing with a smaller wing of the same class (freeride for freeride), do you need to change the mast base position to keep the board balanced?

Sure, if the coe of each wing is different.
I need to move the mast forwards by 1.5" when changing from the 1220 to the 600 wing.

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LeeD said..
Sure, if the coe of each wing is different.
I need to move the mast forwards by 1.5" when changing from the 1220 to the 600 wing.

When you say " mast", do you mean sail mast or foil mast?
Interesting, was thinking you would move the mast back, if anything, for the smaller wing, thanks LeeD

I use Naish Jet wings (1050 & 1250) on a 120L Naish Hover Crossover and weigh 84kgs. Been Windsurf foiling 3 days a week since i started 7 weeks ago. I'm progressing well & going out in up to 25knts. (25knts being gusts not average) . So far when i change up or down in front wing size i've found no need to move my mast. It feels fine all the way back in far rear position for both wings. Having said that there have been days where i have felt under lifted / underpowered and could have moved it forward a tad. I still need to try this. No doubt it will do the trick. I also had a thought.... Instead of rigging say a 4.2 with my mast all the way back in slots, i could maybey rig a 3.7 instead and move the mast forward. It might be nice to have this option some days if your feeling lazy or just want to slow things down. This is something else i want to try. Obviously in more consistent wind than less.

So for me, everything still feels balanced when changing wings without changing mast position. This might not be the case though with gear different to mine. Experimenting is always a good idea. It's good when you try something and it makes something better. If it doesn't at least now you know. That's my my 2 cents worth.

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Sambo # said..
I use Naish Jet wings (1050 & 1250) on a 120L Naish Hover Crossover and weigh 84kgs. Been Windsurf foiling 3 days a week since i started 7 weeks ago. I'm progressing well & going out in up to 25knts. (25knts being gusts not average) . So far when i change up or down in front wing size i've found no need to move my mast. It feels fine all the way back in far rear position for both wings. Having said that there have been days where i have felt under lifted / underpowered and could have moved it forward a tad. I still need to try this. No doubt it will do the trick. I also had a thought.... Instead of rigging say a 4.2 with my mast all the way back in slots, i could maybey rig a 3.7 instead and move the mast forward. It might be nice to have this option some days if your feeling lazy or just want to slow things down. This is something else i want to try. Obviously in more consistent wind than less.

So for me, everything still feels balanced when changing wings without changing mast position. This might not be the case though with gear different to mine. Experimenting is always a good idea. It's good when you try something and it makes something better. If it doesn't at least now you know. That's my my 2 cents worth.

Thanks Sambo, so when you say "mast", do you mean the sail mast or the foil mast?

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Sandman1221 said..

Sambo # said..
I use Naish Jet wings (1050 & 1250) on a 120L Naish Hover Crossover and weigh 84kgs. Been Windsurf foiling 3 days a week since i started 7 weeks ago. I'm progressing well & going out in up to 25knts. (25knts being gusts not average) . So far when i change up or down in front wing size i've found no need to move my mast. It feels fine all the way back in far rear position for both wings. Having said that there have been days where i have felt under lifted / underpowered and could have moved it forward a tad. I still need to try this. No doubt it will do the trick. I also had a thought.... Instead of rigging say a 4.2 with my mast all the way back in slots, i could maybey rig a 3.7 instead and move the mast forward. It might be nice to have this option some days if your feeling lazy or just want to slow things down. This is something else i want to try. Obviously in more consistent wind than less.

So for me, everything still feels balanced when changing wings without changing mast position. This might not be the case though with gear different to mine. Experimenting is always a good idea. It's good when you try something and it makes something better. If it doesn't at least now you know. That's my my 2 cents worth.

Thanks Sambo, so when you say "mast", do you mean the sail mast or the foil mast?

Foil mast

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Sambo # said..

Sandman1221 said..

Sambo # said..
I use Naish Jet wings (1050 & 1250) on a 120L Naish Hover Crossover and weigh 84kgs. Been Windsurf foiling 3 days a week since i started 7 weeks ago. I'm progressing well & going out in up to 25knts. (25knts being gusts not average) . So far when i change up or down in front wing size i've found no need to move my mast. It feels fine all the way back in far rear position for both wings. Having said that there have been days where i have felt under lifted / underpowered and could have moved it forward a tad. I still need to try this. No doubt it will do the trick. I also had a thought.... Instead of rigging say a 4.2 with my mast all the way back in slots, i could maybey rig a 3.7 instead and move the mast forward. It might be nice to have this option some days if your feeling lazy or just want to slow things down. This is something else i want to try. Obviously in more consistent wind than less.

So for me, everything still feels balanced when changing wings without changing mast position. This might not be the case though with gear different to mine. Experimenting is always a good idea. It's good when you try something and it makes something better. If it doesn't at least now you know. That's my my 2 cents worth.

Thanks Sambo, so when you say "mast", do you mean the sail mast or the foil mast?

Foil mast

okay, that is what I thought. Do you move the sail mast base?

You don't have to if you already have a comfortable stance. That's the beauty of the us foil slots. When you move the foil mast position it will increase or decrease lift in relation to your stance. So no need to move foot straps or sail mast base. This applies to my gear at least anyway. Moving sail mast base and and foot straps will also affect lift too. Watch this video

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Sambo # said..
You don't have to if you already have a comfortable stance. That's the beauty of the us foil slots. When you move the foil mast position it will increase or decrease lift in relation to your stance. So no need to move foot straps or sail mast base. This applies to my gear at least anyway. Moving sail mast base and and foot straps will also affect lift too. Watch this video

Thanks, I have a DT box so no moving the foil, and my sail mast base iis all the way back in the track. So concerned if I get a smaller wing and need to move sail mast base back to balance the board.

Moving your feet affects balance much more than moving sail mast.
But moving feet might require removing 6 screws.
Higher aspect foil like more distance from front foot to sail mast base.
Turny foils turn better with less distance.

When changing to a smaller wing I move my sail mast base forward, am using fixed position deeptuttle foils.

The physics (well, my physics ): the lifting force of a foil is always in front of the frontwing due to the stab providing downward lift, creating a moment. A smaller frontwing means relatively the backwing increases in lift (downwards), thus the upward moment will shift forward. A well designed range of wings have COE's in similar positions, so the lever doesnt change.

If the smaller wing has the COE further back, then it depends on the overall geometry what would happen, appearantly the backward shift in COE position for LeeD's naish foil is so big the moment moves back.

Hi Sandman,
where is your mast base with the big wing?
As you know, I've been sailing the AFS 700 A so far. Still haven't used the 800 in lieu of wind and of course I'm wondering how this will impact all the settings.
On the slalom board I sail, the base doesn't go any further back than 128ish. This is just okay, although in marginal conditions I feel I would have to go further back as I do have to press with my back foot a lot. Also, sails up to 6,4m? seem to fit well, my 8m? freeride sail makes the whole thing sticky and hesitant to take off as well as instable once flying.
My guess would be that I can get away with this setup and the bigger wing better. WhiteofHeart's physics seem logical to me.
Let's keep each other updated on the respective experiences with the small/big wing.
The new AHD Compact apparently have their mast base at a miniumum distance from the tail of 122cm, so this would probably be ideal for the AFS freeride foils.

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WhiteofHeart said..
When changing to a smaller wing I move my sail mast base forward, am using fixed position deeptuttle foils.

The physics (well, my physics ): the lifting force of a foil is always in front of the frontwing due to the stab providing downward lift, creating a moment. A smaller frontwing means relatively the backwing increases in lift (downwards), thus the upward moment will shift forward. A well designed range of wings have COE's in similar positions, so the lever doesnt change.

If the smaller wing has the COE further back, then it depends on the overall geometry what would happen, appearantly the backward shift in COE position for LeeD's naish foil is so big the moment moves back.

Thanks WhiteofHeart, that is good information, yeah, the AFS F800 and F700 wings are part of the same range, I just do not have any room in the sail mast base track to go back further, was concerned if going to the F700 would make me want to do that. Will order the F700 and see, moving the sail mast base forward would be fine.

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ZeeGerman said..
Hi Sandman,
where is your mast base with the big wing?
As you know, I've been sailing the AFS 700 A so far. Still haven't used the 800 in lieu of wind and of course I'm wondering how this will impact all the settings.
On the slalom board I sail, the base doesn't go any further back than 128ish. This is just okay, although in marginal conditions I feel I would have to go further back as I do have to press with my back foot a lot. Also, sails up to 6,4m? seem to fit well, my 8m? freeride sail makes the whole thing sticky and hesitant to take off as well as instable once flying.
My guess would be that I can get away with this setup and the bigger wing better. WhiteofHeart's physics seem logical to me.
Let's keep each other updated on the respective experiences with the small/big wing.
The new AHD Compact apparently have their mast base at a miniumum distance from the tail of 122cm, so this would probably be ideal for the AFS freeride foils.

Thanks ZeeGerman, my sail mast base is all the way back with the Wind95 foil/F800 wing on a Goya Bolt Pro 135L and is perfectly balanced (108.5 cm from center of mast base to front foil box screw and 119.5 cm to rear foil box screw). The F700 and F700a wings look similar but are very different, including that the F700a weighs ~220 grams more, presumably due to a thicker dihedral. According to Bruno Andre at AFS the F700 is faster and more stable at high speeds versus the F700a. I am looking to use the F700 with my 7.2 and 5.8 Aerotech Freespeed sails (no cambers) in 18+ knot winds.

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LeeD said..
Moving your feet affects balance much more than moving sail mast.
But moving feet might require removing 6 screws.
Higher aspect foil like more distance from front foot to sail mast base.
Turny foils turn better with less distance.

Thanks LeeD, I have my foot straps all the way back, and board is balanced, was just concerned if I had to move anything further back with the F700 wing, but according to WhiteofHeart will need to do the opposite, which is fine.

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Sandman1221 said..

ZeeGerman said..
Hi Sandman,
where is your mast base with the big wing?
As you know, I've been sailing the AFS 700 A so far. Still haven't used the 800 in lieu of wind and of course I'm wondering how this will impact all the settings.
On the slalom board I sail, the base doesn't go any further back than 128ish. This is just okay, although in marginal conditions I feel I would have to go further back as I do have to press with my back foot a lot. Also, sails up to 6,4m? seem to fit well, my 8m? freeride sail makes the whole thing sticky and hesitant to take off as well as instable once flying.
My guess would be that I can get away with this setup and the bigger wing better. WhiteofHeart's physics seem logical to me.
Let's keep each other updated on the respective experiences with the small/big wing.
The new AHD Compact apparently have their mast base at a miniumum distance from the tail of 122cm, so this would probably be ideal for the AFS freeride foils.

Thanks ZeeGerman, my sail mast base is all the way back with the Wind95 foil/F800 wing on a Goya Bolt Pro 135L and is perfectly balanced (108.5 cm from center of mast base to front foil box screw and 119.5 cm to rear foil box screw). The F700 and F700a wings look similar but are very different, including that the F700a weighs ~220 grams more, presumably due to a thicker dihedral. According to Bruno Andre at AFS the F700 is faster and more stable at high speeds versus the F700a. I am looking to use the F700 with my 7.2 and 5.8 Aerotech Freespeed sails (no cambers) in 18+ knot winds.

I guess it will be great fun. The F700A is fun, too, although it might not be that stable. Can't compare yet. You're right, it is really heavy. So in contrast, the F800 feels unnaturally lightweight.

Alright, just ordered the F700 direct from AFS, hopefully get in time for Christmas, cause that is what Santa got me! Tried to get from a US dealer but could not.

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ZeeGerman said..

Sandman1221 said..

ZeeGerman said..
Hi Sandman,
where is your mast base with the big wing?
As you know, I've been sailing the AFS 700 A so far. Still haven't used the 800 in lieu of wind and of course I'm wondering how this will impact all the settings.
On the slalom board I sail, the base doesn't go any further back than 128ish. This is just okay, although in marginal conditions I feel I would have to go further back as I do have to press with my back foot a lot. Also, sails up to 6,4m? seem to fit well, my 8m? freeride sail makes the whole thing sticky and hesitant to take off as well as instable once flying.
My guess would be that I can get away with this setup and the bigger wing better. WhiteofHeart's physics seem logical to me.
Let's keep each other updated on the respective experiences with the small/big wing.
The new AHD Compact apparently have their mast base at a miniumum distance from the tail of 122cm, so this would probably be ideal for the AFS freeride foils.

Thanks ZeeGerman, my sail mast base is all the way back with the Wind95 foil/F800 wing on a Goya Bolt Pro 135L and is perfectly balanced (108.5 cm from center of mast base to front foil box screw and 119.5 cm to rear foil box screw). The F700 and F700a wings look similar but are very different, including that the F700a weighs ~220 grams more, presumably due to a thicker dihedral. According to Bruno Andre at AFS the F700 is faster and more stable at high speeds versus the F700a. I am looking to use the F700 with my 7.2 and 5.8 Aerotech Freespeed sails (no cambers) in 18+ knot winds.

I guess it will be great fun. The F700A is fun, too, although it might not be that stable. Can't compare yet. You're right, it is really heavy. So in contrast, the F800 feels unnaturally lightweight.

You will really like the F800, it is stable and fast but very maneuverable too, should help with your carving/foiling jibes.

I sail the AFS-2 with both F700 and F800 wings on a formula board with fixed-position DT finbox and fixed-position footstraps. The only adjustment is the sail mast base. I set the sail mast base at 42" forward of the front fin bolt for a 6.4 sail. Fine-tune for different sail sizes to balance the mast base pressure exerted by the sail.

The center of lift of both the F700 and F800 wings is exactly in the same place. I can swap them without having to change anything else.

Like mentioned above, changing your foot position is hugely more noticeable than changing the sail mast base position.

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segler said..
I sail the AFS-2 with both F700 and F800 wings on a formula board with fixed-position DT finbox and fixed-position footstraps. The only adjustment is the sail mast base. I set the sail mast base at 42" forward of the front fin bolt for a 6.4 sail. Fine-tune for different sail sizes to balance the mast base pressure exerted by the sail.

The center of lift of both the F700 and F800 wings is exactly in the same place. I can swap them without having to change anything else.

Like mentioned above, changing your foot position is hugely more noticeable than changing the sail mast base position.

Thanks segler, that is exactly what I needed to know! When I saw your post I was worried for a second since I just ordered the F700 wing. I know about foot position, have that dialed in, but can not move sail mast base back any further, so that was my main concern with going from the F800 to F700 wing. I have been keeping the sail mast base at the same position (42-3/4" center-to-center mast base/front foil box screw) for all my sails (9.0-5.8) and feel balanced, but can not go closer. You weigh more than me so moving sail mast base to 42" would give you more lift.

WofH's physics explain why when I switch from my i99 to my i76 riding a 2018 Wizard (DT) the lift goes way forward. Double whammy: smaller wing means rear stab is exerting relatively "more control" and the i76 has a neck that pushes the CofL forward. I'm iced up here in Ohio but I can't wait to experiment next spring with moving sail mast forward and shimming the stab for less down lift. Foot straps are in full forward position. 180 lbs./82kg.

Got the AFS F700 wing today! DHL took care of everything and I did not have to pay a tariff or import duty.