Lots of fuselages are spec'd like: 110+7 or 115+10. I get that this is moving the front wing forward but I wonder what this accomplishes? Could be more stability from increasing the distance between the front wing and stabilizer. It would also move a person's center of mass forward on the board but I'm not sure how that helps or if thats just the side effect of using +10 for more stability.

Are there any rules of thumb in terms of a lighter person would benefit more/less/same as a heavier person with something like +10?

Very very basic rule of thumb would be:

The more forward the front wing is and the less stab (angle or size) you'll need to be stable and balanced (not having the nose going down or having to push a lot on the rear foot).

The downside is: the more forward and away from the mast the wing is, the more your mast and/or will twist and the less control you will have (with a possible drag increase). Not so a problem if you go at low speed in light wind or if you have a super mega stiff mast and fuselage.

If you want to simplify even more: the more the wing is forward, the more your foil is going to be powerful. From that, you can assume what it does for someone light or heavy, in light or strong breeze.

The way I see it: a longer fuselage gives you better stability (pitch control). The wing further forward gives you power.
for example, starboard 115 black fuselage and the 115plus are both 115 cm long but the 115plus has the front wing further forward and that gives you more power.

All other things being equal (such as the 115 fuselage length, choice of wing and stab, stab shimming, footstrap position, sail size and type, and sail base position), moving the wing further forward of the foil mast (such as the + and ++) quite simply moves the balance point forward. Nothing else.

At any given speed, the front wing generates the same amount of lift no matter where it is positioned. If you position it further forward you get an increase in lever length and resultant stronger moment arm lifting up. Basic physics.

There is no change in actual power, but there is a change in the location of the power. If you perceive it as increased power, it means you are having to press harder with your front foot.

If you want to use a + or ++ fuselage for freeride foiling, just mount it to a board that has the finbox further aft (such as most of the old slalom boards out there). The whole point is balancing the up lift of the front wing.

A friend of mine runs a SB 115 race foil on an old SB slalom board and is nicely balanced. I run a SAB race foil on a custom Roberts with the finbox far aft and am nicely balanced.

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segler said..
If you want to use a + or ++ fuselage for freeride foiling, just mount it to a board that has the finbox further aft (such as most of the old slalom boards out there).

Not necessary. There are so many adjustments available. Shim, moving mast base, footstrap, etc. That's how IQFoilers use the same kit for slalom and up/downwind. Even with the IQ (+) I'm only running the mast base from 104-110cm from the front screw depending on what shim I'm using.

Further forward (on freeride kit) helped a lot in jibes. I can ride with the front wing further back but it took a lot of rear pressure to maintain lift. My jibes improved a lot with using a jack plate to keep moving the wing until that wasn't as much of a problem. Still working on getting them consistent though.

But, with where I have that set up I can fly comfortably upwind or downwind out of the rear footstrap, just the foot in front, for about a mile or so without too much rear leg burning. It does help to be further back and in the rear. I think a lot of people with really aft front wings aren't using rear straps and get their rear foot pretty far back there.

But with the forward wings I do tend to fly zigzag more instead of reaching. Way better upwind/downwind angles when coupled with a cammed foil sail.

Same with IQFoil kit, going an extra +0.5 helped in the jibes. I was running with 0 shim and it was not as easy to jibe. Especially in light wind. High wind is a different story and the speed and jibes are easier to pull off even with imperfect technique. Haven't tried race gear with a less forward front wing (105+ fuse) in a while but I imagine I'll have to move the mast base further back to stay up in the jibes, as when I kept the mast base in the same spot as with the 115+ I was killing my back legs to stay upwind.

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segler said..
All other things being equal (such as the 115 fuselage length, choice of wing and stab, stab shimming, footstrap position, sail size and type, and sail base position), moving the wing further forward of the foil mast (such as the + and ++) quite simply moves the balance point forward. Nothing else.

At any given speed, the front wing generates the same amount of lift no matter where it is positioned. If you position it further forward you get an increase in lever length and resultant stronger moment arm lifting up. Basic physics.

There is no change in actual power, but there is a change in the location of the power. If you perceive it as increased power, it means you are having to press harder with your front foot.

Friend of mine and I both tested SB IQ 105 vs 115+ fuselage. 115+ gives us more more power and better lift on low wind days. 115 is more stable as mentioned by others. However, 115+ compared to the 105, moves the location of the power forward which for me using the 1000 wing was not possible since I had to step on above or forward of the frontstraps on my racefoil board (FMX slalom foil)

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SA_AL said..

segler said..
All other things being equal (such as the 115 fuselage length, choice of wing and stab, stab shimming, footstrap position, sail size and type, and sail base position), moving the wing further forward of the foil mast (such as the + and ++) quite simply moves the balance point forward. Nothing else.

At any given speed, the front wing generates the same amount of lift no matter where it is positioned. If you position it further forward you get an increase in lever length and resultant stronger moment arm lifting up. Basic physics.

There is no change in actual power, but there is a change in the location of the power. If you perceive it as increased power, it means you are having to press harder with your front foot.

Friend of mine and I both tested SB IQ 105 vs 115+ fuselage. 115+ gives us more more power and better lift on low wind days. 115 is more stable as mentioned by others. However, 115+ compared to the 105, moves the location of the power forward which for me using the 1000 wing was not possible since I had to step on above or forward of the frontstraps on my racefoil board (FMX slalom foil)

Did you either change shims or move the mast base forward when you used the 1000/115+? I use it all the time with the Millineum without a problem and I'm on the small side of things.

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shmish said..
What does the "+10" on a fuse do?

Adds a bit of safety if you're in the artillery corps

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Looks like we have a replacement for D-lee
Funny thing is mark was one of the outspoken people that got D-LEE blocked
now he spits out the same type dribble

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Gwarn said..
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Looks like we have a replacement for D-lee
Funny thing is mark was one of the outspoken people that got D-LEE blocked
now he spits out the same type dribble

Just a bit of humor something this world desperately needs

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Gwarn said..
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Looks like we have a replacement for D-lee
Funny thing is mark was one of the outspoken people that got D-LEE blocked
now he spits out the same type dribble

Just when I was going to reply with something like the +0 fuses were a "blast", "really blew up", etc.

That was, imho, funny and clever. Even better is that his comment wasn't at the expense of someone else. What got LeeD blocked was repetitively posting and telling everyone they were wrong because he used to be a pro in 1988.

A fun trip down memory lane on the very same topic featuring LeeD: www.seabreeze.com.au/forums/Windsurfing/Foiling/Starboard-Fuse-115-vs-115-?page=2