Hi all,

I have two different boards (Starboard 85cm and Tabou 91) and a variety of different Starboard foil (fuse and wing) combos. Consequently my boards are not set up for one specific foil. The downside of this is that switching fuselages in particular (from Starboard 109 Evo to 99 Evo) means the optimum footstrap/mast base position s not always the same and I end up doing a lot of moving the mast base on the water to try to get the flight trim right. I can't change the footstraps on the water.

My question is whether anyone has a rule of thumb regarding when to change footstrap position vs moving the mast base? To give an example - My tabou 91 has the front footstraps in the forward-most holes. This is about right for the 109 fuse. But when I change to the 99 fuse (front wing significantly further back) the footstraps could probably go further back. I end up running the mast base as far back in the slot as it can go (about 106cm).

To my way of thinking, footstrap position seems like a 'macro' adjustment, whereas mast base is a 'micro' adjustment. But what do you think? Is it a case of keep moving the mast base back until you run out of slot; if more rear-bias is required, then move footstraps back and reset mast base to middle and adjust from there, etc?

I am interested to hear from others as to what dictates a change in footstrap position vs mast base position?

Thanks,

S

I always run the footstraps as far back as possible and then use the mast base and rear wing shim to find the trim i want/need. I have it set up so that when i crank the sail on fully it levels out my board and gives me max speed & height upwind (VMG) or downwind.

for me in order of micro to macro

mast base -> shim -> foot strap

I'm small and kind of limited on where to put straps on some boards as they seem to be set up for people with wider stances than I'm comfortable with (ie, even with the front straps at the back, the back straps might be in the front holes). Like madlad, I'd bias straps to the back., though, as it's generally easier to increase "nose" pressure vs decreasing it.

I don't use different foil and board combinations, because it makes me sail like **** when I switch. For me the universal to foil mast (or front wing) is a really crucial variable to get the right balance of stability and agility. So I am always looking to keep that in my preferred range. So I start there. Then I would put then I would adjust the footstraps, but if I need more adjust than what is comfortable with my strap position, then I shim

I think you put the straps first so that the center of the front wing is in the middle, then adjust the rest...

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powersloshin said..
I think you put the straps first so that the center of the front wing is in the middle, then adjust the rest...

That kind of works until it doesn't. Exhibit A: using a regular and plus fuse on the same board Exhibit B (just for fun): get the plus plus fuse out of mothballs and use that, too.

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Paducah said..
for me in order of micro to macro

mast base -> shim -> foot strap

I'm small and kind of limited on where to put straps on some boards as they seem to be set up for people with wider stances than I'm comfortable with (ie, even with the front straps at the back, the back straps might be in the front holes). Like madlad, I'd bias straps to the back., though, as it's generally easier to increase "nose" pressure vs decreasing it.

Even if you aren't small. Average height for men is about 175cm, female 160cm. The stance often is still too wide for mid-height people even on the smallest setting. This can be due to minimising board weight by only having two footstrap positions. ( It is only a few-10's of grams to have a few more holes to a row ( imho minimising weight in this aspect isn't a good compromise ).

This sizing issue also applies to boom-cutout's, particularly wave sails... ie: if you see a 175cm sailor using the bottom of the cut-out, then the cut-out is too high.

I'll chime in with my experience.

IQFoil board: Have never changed the gross position of the straps based off the recommended setup. I think maybe the rear straps could move forward a hole to keep from overloading the rear when more downwind.

FoilX 145: I tweaked it some, from outboard to inboard and back again, and tweaking the strap position, but ended up getting most adjustment out of the foil position (moving it as forward as I could). I put the straps back more because it still was diving too much in the jibes for me.

Slingshot Freestyle 115: I moved the straps all the way forward almost from the get-go to keep the board buoyancy towards the center helping me. I put the foil more and more forward to make it more stable during the jibes.

The FoilX had a lot of buoyancy aft which meant that it wasn't as sensitive as something as the Freestyle when moving the straps backward. If I had the Freestyle more aft, at my weight (210lbs), it would just bog down and plow through the water.

Your boards are more on the freerace/racy side so there is probably a sweet spot for those foil setups. When I move from the upwind/downwind fuse vs. the slalom fuse on the IQFoil I don't tweak the straps, but it makes a big difference on my riding style because on the longer fuse it is sketchy to reach when powered up. It's a lot more comfortable on the slalom fuse to sail more reachy. I suppose I could tweak the straps some but it's such a pain I don't bother.

Sometimes, it's better to keep it simple.
As Maciek Rutkowski said in one of his video: set what is harder to change first then what is easier.
E.g: Set your footstraps first, then set your foil, then you can play with the mast base and then you can change your boom heigh anytime on the water.
Everytime you change one thing, it will influence all the others so it can quickly become overcomplicated.

Distance between your backstrap & mastbase is the total distance you can vary your weight across. The wider this is the more stable, the smaller the more manouvrable (or unstable). I'd personally for a race / freerace setup go with the footstraps back and compensate with the mastfoot, as that allows for a wider setup overal e.g. more stability.

This all is under the understanding that you will dedicate to the sail, your harness lines are balanced (no excessive front or backhend pressure as that translates to front / backfoot pressure you're giving instead of mastfoot pressure) & put your weight in the harness, if you dont then the mastfoot ofcourse has much less of an effect on the whole thing and you might have to put the backstrap forward to keep it all under control.

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WhiteofHeart said..
Distance between your backstrap & mastbase is the total distance you can vary your weight across. The wider this is the more stable, the smaller the more manouvrable (or unstable). I'd personally for a race / freerace setup go with the footstraps back and compensate with the mastfoot, as that allows for a wider setup overal e.g. more stability.

I am not totally convinced, but maybe I am wrong?
When You have a wide setup (mastfoot more to the front, straps back) then every small movement of the body has a great impact on the trim, because the leverage is high.
With a narrower setup (mastbase more to the back, straps forward) small movements (weight shifting to the front or back) has less impact on the board trim.
So what is more stable?
Beside that the shim on the stabilizer also effects board trim al lot. You can use more lift on the stabilizer and compensate with mastfoot/straps more forward or less lift on the stabilizer and mastfoot/straps more to the back.

I would start like this:

- mastbase in the middle (depending on the board but normally around 108 to 110 cm from the front screw of the foil on slalom boards). Extreme mastbase positions also effect the stance of the sail, for example if the mastbase is very far forward, You will rake the sail more back, with the lower leech touching the board (close the gap), what is not really recommmended in foiling.
- backwing shim for the stabilizer that is usual (common sense) for Your foil (look at settings here in the forum, what are used by most of the riders, or what is recommended by the foil manufacturer))
- then place the straps, so that You get a stable setup
This is the basic setup!

- then fine tune from there with different mastbase and shim settings, boom height and sail trim (downhaul, outhaul). There are many things to try, so it can take time to find a perfect setup!