I would like to ask about the relationship between sail size and board width for narrower foil boards. How much less m^2 could a 65cm wide board handle than say a 70cm or 75cm wide board? Is there a limit on what sail sizes you can use with a central rear strap?

-im looking at buying a smaller foil board in the 100-115l range thats more convenient to lug around however I mostly foil in lighter winds, and this would also help me decide if i need to get a liftier foil

Cheers

I think I tend to go a bit to the extreme but also I think it depends on tail width.

I have a 115 slingshot freestyle with center rear strap and when I'm going at the lightest wind I can use a 7.5 gator or 7.0 foil glide. I don't feel super cramped but when sailing upwind I am on the rail with my rear foot, lateral to the center rear strap, and similar on the front.
It feels a lot more appropriate with a 5.6 freek or smaller. I'm a bit large at about 210lbs and 6'1 so it takes a little bit more. Any lighter wind than those sails and I'm on the iqfoil 95cm wide rectangular tail with a 8.0 or 9.0.

I also rode a foilx 145 which has more width in the tail but an 8.0 foil glide felt cramped to me. 7.0 not so much.

Wondering about the largest new r4d 4 batten as a 6.4? may be powerful enough for me on the light days with the freestyle.

I'm wondering the same thing about the new breed of PWA all-around 85 boards. Can they handle 9.0 sails the likes of olympic IQ HGO?

Totally agree that tail width makes the difference, also consider front wing width

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Dishpet said..
I'm wondering the same thing about the new breed of PWA all-around 85 boards. Can they handle 9.0 sails the likes of olympic IQ HGO?

I think it will work, but only with smaller frontwings like a 75 wide, 550. The slalom pros use 650 or 550 as their lightwind setup.

For bigger frontwings like a 800 or a 900 a wider board would make it easier to control the wing, because on the wider board You stand more outside and have more leverage.

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cad184 said..

Dishpet said..
I'm wondering the same thing about the new breed of PWA all-around 85 boards. Can they handle 9.0 sails the likes of olympic IQ HGO?

I think it will work, but only with smaller frontwings like a 75 wide, 550. The slalom pros use 650 or 550 as their lightwind setup.

For bigger frontwings like a 800 or a 900 a wider board would make it easier to control the wing, because on the wider board You stand more outside and have more leverage.

If it's simply a matter of width, yes. Some of the newest boards, however, are a bit thinner so heavier sailors should plan accordingly. Board width originally was more about fin size than sail size. It was not uncommon 25 yrs ago to run 9+ meter sails on <70cm wide boards and raceboards still do it all the time. Many of the brands top out their slalom sails in the mid 8s and their board specs reflect that. You'll also notice that there is no wing recommendations (that I'm aware of) for boards. In fact, Phantom, whose widest current production board is 86 cm is reintroducing a 950cm wing to their product line (along with an existing 800).

Front wing width has pretty much very little to do with board width. I use 80-100cm wide wings all the time on my 75cm/125 l higher wind board and DW wingers use up to 1350mm wings on their sub 60cm wide boards . First, the outside bits of a wide, modern wing aren't really producing lift but reducing drag. Second, the force of the wing is up (ignoring the very minor aspect of any spanwise flow) - it's the foil mast that's exerting a torque. It doesn't matter if the wing is 450 or 1000mm, the force is still up. Wider wings are also (generally) more stable on the roll axis due to their width (why biplane airplanes with their short wings were favored for their maneuverability).

An HGO 9.0 on a JP 135 (similar in size/width to modern PWA boards although likely narrower at the rear strap)

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Dwyryd said..
I would like to ask about the relationship between sail size and board width for narrower foil boards. How much less m^2 could a 65cm wide board handle than say a 70cm or 75cm wide board? Is there a limit on what sail sizes you can use with a central rear strap?

-im looking at buying a smaller foil board in the 100-115l range thats more convenient to lug around however I mostly foil in lighter winds, and this would also help me decide if i need to get a liftier foil

Cheers

Windfoil Board Size Recommendations (my opinion): 5-12kt: Use a 160-200L board.10-16kt: A 130-200L board is suitable. 15-20kt: 100-200L, but the smaller boards work best in stable wind conditions.I am using a 115L setup with a 7m? Severne Glide 2 sail. I can even handle a 10m sail, but it would be somewhat of a masochistic experience. A 7m? sail can be quite heavy and unstable when not levitating in wind conditions around 0-10 knots. Big sail + small board + low wind + pumping technique + straps in the center (yes, they are needed when pumping on such a small board to avoid rolling over) = not a very pleasant session. When levitating, the back footstrap is not needed. I usually place my foot on the edge.Compared to my 91cm board, I get twice as tired on the small board with the big sail in low wind conditions.
I can write a book about how many difficulties arise in that situation. In a nutshell, if you're levitating, it's not that bad, but lack of wind and pumping on a small board is an exhausting struggle.

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Paducah said..

cad184 said..

Dishpet said..
I'm wondering the same thing about the new breed of PWA all-around 85 boards. Can they handle 9.0 sails the likes of olympic IQ HGO?

I think it will work, but only with smaller frontwings like a 75 wide, 550. The slalom pros use 650 or 550 as their lightwind setup.

For bigger frontwings like a 800 or a 900 a wider board would make it easier to control the wing, because on the wider board You stand more outside and have more leverage.

If it's simply a matter of width, yes. Some of the newest boards, however, are a bit thinner so heavier sailors should plan accordingly. Board width originally was more about fin size than sail size. It was not uncommon 25 yrs ago to run 9+ meter sails on
Front wing width has pretty much very little to do with board width. I use 80-100cm wide wings all the time on my 75cm/125 l higher wind board and DW wingers use up to 1350mm wings on their sub 60cm wide boards . First, the outside bits of a wide, modern wing aren't really producing lift but reducing drag. Second, the force of the wing is up (ignoring the very minor aspect of any spanwise flow) - it's the foil mast that's exerting a torque. It doesn't matter if the wing is 450 or 1000mm, the force is still up. Wider wings are also (generally) more stable on the roll axis due to their width (why biplane airplanes with their short wings were favored for their maneuverability).

An HGO 9.0 on a JP 135 (similar in size/width to modern PWA boards although likely narrower at the rear strap)

That's a 7m HG5 on that video. With the IQfoil 900 front wing and 115+ fuselage.
I tried the 9m HGO a few times on that board (JP 135) and although it works, I didn't feel confortable when going upwind.

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jusavina said..

Paducah said..
A bunch of stuff.

That's a 7m HG5 on that video. With the IQfoil 900 front wing and 115+ fuselage.
I tried the 9m HGO a few times on that board (JP 135) and although it works, I didn't feel confortable when going upwind.

In that case, I stand corrected. Appreciate the info! Curious about it upwind, was it the narrower tail?

Are you sure about the foil wing? That doesn't look anything like my 900 and when you originally posted, iirc, you mentioned it was a custom.

My comments about smaller boards and big wings still stand, however.

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Paducah said..

jusavina said..

Paducah said..
A bunch of stuff.

That's a 7m HG5 on that video. With the IQfoil 900 front wing and 115+ fuselage.
I tried the 9m HGO a few times on that board (JP 135) and although it works, I didn't feel confortable when going upwind.

In that case, I stand corrected. Appreciate the info! Curious about it upwind, was it the narrower tail?

Are you sure about the foil wing? That doesn't look anything like my 900 and when you originally posted, iirc, you mentioned it was a custom.

My comments about smaller boards and big wings still stand, however.

Sorry, you are absolutely right about the wing, I was using a custom one that day. I can't remember the size but it was around 900/950.

To answer your question about why it didn't feel right upwind, I would think that's probably due to the narrower tail indeed. It feels harder to sheet in than on the IQ board.

I haven't tried that combo much more because I only use the 9m on the IQ board for racing and the rest of the time, I just rig the 7m with different front wing sizes (from 950 with 1m span to 450) on the JP 135 and go freeriding.

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wrzaskun said..

Dwyryd said..
I would like to ask about the relationship between sail size and board width for narrower foil boards. How much less m^2 could a 65cm wide board handle than say a 70cm or 75cm wide board? Is there a limit on what sail sizes you can use with a central rear strap?

-im looking at buying a smaller foil board in the 100-115l range thats more convenient to lug around however I mostly foil in lighter winds, and this would also help me decide if i need to get a liftier foil

Cheers

Windfoil Board Size Recommendations (my opinion): 5-12kt: Use a 160-200L board.10-16kt: A 130-200L board is suitable. 15-20kt: 100-200L, but the smaller boards work best in stable wind conditions.I am using a 115L setup with a 7m? Severne Glide 2 sail. I can even handle a 10m sail, but it would be somewhat of a masochistic experience. A 7m? sail can be quite heavy and unstable when not levitating in wind conditions around 0-10 knots. Big sail + small board + low wind + pumping technique + straps in the center (yes, they are needed when pumping on such a small board to avoid rolling over) = not a very pleasant session. When levitating, the back footstrap is not needed. I usually place my foot on the edge.Compared to my 91cm board, I get twice as tired on the small board with the big sail in low wind conditions.
I can write a book about how many difficulties arise in that situation. In a nutshell, if you're levitating, it's not that bad, but lack of wind and pumping on a small board is an exhausting struggle.

This matches my experience and you brought up what I neglected to mention: I can take the 7.0 out of my 115 freestyle and it's very fatiguing if the wind drops. That particular board I can waterstart in very little wind because of how it sinks with my weight, but balancing around in chop with no wind is precarious. I can do it, which is why I like that setup, but yes, very fatiguing.

If I expect deep lulls in those conditions it's way better to be on the big board at least. 200l of iqfoil board and any sail is a lot easier to slog around on for sure.

I was not able to do that on the wizard 114 though, at my weight. It was very hard for me to uphaul at that time, vs the 115 freestyle I can uphaul while the board sinks a bit. Some people do a lot better with the chopped no volume nose shapes. I have not yet proven to be one of those people.

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jusavina said..


To answer your question about why it didn't feel right upwind, I would think that's probably due to the narrower tail indeed. It feels harder to sheet in than on the IQ board.

I haven't tried that combo much more because I only use the 9m on the IQ board for racing and the rest of the time, I just rig the 7m with different front wing sizes (from 950 with 1m span to 450) on the JP 135 and go freeriding.

Thanks for that info. I think it helps inform the question about board sizing. Based on that video, I've more often dragged out the JP 135 that was originally for my son and have used it quite often recently since, being an older board, is easier just to chuck in the back of the van. Similarly, 7.0 and 5.2 (I'm on the small size) with various wings.

I thought of that video since it was the one that inspired me to stretch the legs of my board. btw, for the old and slow in the crowd, your race videos are fun to watch.

I've had some great light wind sessions on 8.7 (so almost 9....) on my 85cm wide "PWA" board with 800 front wing. Feels perfectly nice and balanced, and in rough conditions probably less physical than on a 95/100 board. At the margins (ie extreme angles) I had to give a little to the iQ/FW boys, but that was at least in part due to my slightly smaller wing (v. their 900s); speed was good though. Eager to try the new 950 but I suspect the slightly narrower board will still be somewhat less efficient esp upwind. But it is much nicer to sail than the big doors :)

From using some smaller wave sails, the single condition in which I notice lack of width in the tail is trying to crank upwind. 2m sail size difference was not noticeable in the reach, the minute i wanted to get on an upwind angle I felt I wanted my back foot further out, however this is no real issue for cruising around. Seems almost as though the relationship is sail size X degrees upwind^2 = desired width