I've been windfoiling for 2 seasons with freeride gear, still a lot to learn and only on flat & choppy waters so far.
I've always wanted to use my wave sails (Goya Banzai) in sizes as small as possible to get me going. Not interested in max speed and racing.
from the start I have trimmed the sails with minimum downhaul and low outhoul (using upper clew ring for tighter leech) so the leach remains tight (only slight looseness between top 2 battens) and battens that protrude well ahead of the mast.
while this works for getting on the foil I soon feel that the sail becomes unstable this way and very back-handed which makes it difficult to control when going downwind. Need to switch to smaller size quickly but then its often hard to get going. I foil in the Netherlands on gusty spots below 20 knots.
probably overdoing it on the low-wind trim.
when trimmed like I do for wavesailing it feels like there is too little power to get up and go in the light winds that I foil in.
I use sizes 5.0 4.7 4.2

Hmm...
Rigging for foil is so much personal preference. I don't really alter the downhaul between fin and foil on my wave sails anymore. The only thing I tend to do when I go foil is add outhaul (~1 inch), and switch to upper clew eyelet if I have one. Seems to me that outhaul can be adjusted way more than downhaul without making the sail unstable.

^^^agree with that^^^
it seems like the right thing to do, but I've found trying in the past that running a significant amount less downhaul just destabilises the sail too much. Foil sails I've found, are made to the correct shape everywhere else with a tighter leech. On a normal sail you're better off just setting the downhaul to spec pretty much.

I use a Goya Fringe and use about 1/2 the recommended down haul on the 3.7 and 3.0. The deep luff powers up quickly and it's such a small sail, doesn't seem to affect stability. However, if I'm over powered, i use the out haul to flatten the luff. This last week I was on my 3.0 in 30 knots, but it got up to 41 knot gusts and I was in survival mode nothing helped in that situation. On my 5.3 a deep luff is too much and I get over powered quickly in the gusts, so I use full downhaul and shallow luff for that setup. The larger sail size can be a handful for me on free ride gear. Our gusts are almost always double the average wind speed so I rig for the gusts. If that means slogging between the wind lines. So be it. The fun for me is in the gust with small sails.

Select to expand quote

thedoor said..
Hmm...
Rigging for foil is so much personal preference. I don't really alter the downhaul between fin and foil on my wave sails anymore. The only thing I tend to do when I go foil is add outhaul (~1 inch), and switch to upper clew eyelet if I have one. Seems to me that outhaul can be adjusted way more than downhaul without making the sail unstable.

Thx for the views. you do mean ADD outhaul when foiling? As I always try to get the sail as full as possible so would figure you reduce outhaul for foil vs fin?

I have rigged Fringe similar to how I rig it for light wind or comfortably powered wave riding. The same way as Levi rigs here in this clip.

And if you do release the downhaul significantly, be prepared to add some outhaul to compensate.

Hi tom ; i am Bart also from Holland; where do you live? I foil a lot at schokkerhaven with my horue foilstyle board combined with several freekfoil sails. Here we have a couple of nice guys who foil al lot at schokkerhaven. Maybe we meet there?

?si=--9jlnfBealJ7-12

Greetings from Bart

I use extra downhaul on my wave sails when foiling. Unless you are way powered the foil doesn't create enough load to open the sail up so the leach stay too tight. Extra downhaul puts more static twist in the sail so it works better lightly loaded. Result is better acceleration and better glide at the expense of a little less bottom end grunt.

Select to expand quote

TomDW said..

thedoor said..
Hmm...
Rigging for foil is so much personal preference. I don't really alter the downhaul between fin and foil on my wave sails anymore. The only thing I tend to do when I go foil is add outhaul (~1 inch), and switch to upper clew eyelet if I have one. Seems to me that outhaul can be adjusted way more than downhaul without making the sail unstable.

Thx for the views. you do mean ADD outhaul when foiling? As I always try to get the sail as full as possible so would figure you reduce outhaul for foil vs fin?

Reduce downhaul to get the upper leech a little tighter so that it is less reactive and shifts less in gusts. More outhaul to keep the center of pressure more stable, especially when you have a lot of apparent wind on foil pushing close to 45 deg.

Highly recommend trying adjustable outhaul to feel the difference because it's immediate and you notice a small 1/2cm change can make a world of difference going upwind vs. reaching or downwind.

Agree with most here, less downhaul makes the sail feel heavy once you get going. Do you try pumping to get on the foil ?

Select to expand quote

powersloshin said..
Agree with most here, less downhaul makes the sail feel heavy once you get going. Do you try pumping to get on the foil ?

Clearly not pumping enough yet. @Bart: I sail in Zeeland, that's a little far away from where you're at

Select to expand quote

TomDW said..

thedoor said..
Hmm...
Rigging for foil is so much personal preference. I don't really alter the downhaul between fin and foil on my wave sails anymore. The only thing I tend to do when I go foil is add outhaul (~1 inch), and switch to upper clew eyelet if I have one. Seems to me that outhaul can be adjusted way more than downhaul without making the sail unstable.

Thx for the views. you do mean ADD outhaul when foiling? As I always try to get the sail as full as possible so would figure you reduce outhaul for foil vs fin?

Yeah I add outhaul for foiling. I like a flatter sail, it does mean that I carry a 1/2 size up but that helps water starting. I believe I like flatter because It seems to be more controllable when pointing, and it seems to me that I get more out of my pumps with a less baggy sail. I reckon I am an outlier thou.

Finally had a foiling session today after a couple of weeks off due to persisting cold and low wind in Northern Europe. Took advice here at heart and trimmedthe Banzai 5'0 like Levi does and how I used to trim it for waves. Took half a metre more than I normally would have, sail handled much better in the 9-10m/s gusts. Sail wasindeed more pumpable than when rigged baggy. I initially followed advice in this forum when I started to yrs ago to always rig baggy but clearly that's not suitable for the gusty conditions I usually ride in.
enjoyed it!!

Select to expand quote

TomDW said..
Finally had a foiling session today after a couple of weeks off due to persisting cold and low wind in Northern Europe. Took advice here at heart and trimmedthe Banzai 5'0 like Levi does and how I used to trim it for waves. Took half a metre more than I normally would have, sail handled much better in the 9-10m/s gusts. Sail wasindeed more pumpable than when rigged baggy. I initially followed advice in this forum when I started to yrs ago to always rig baggy but clearly that's not suitable for the gusty conditions I usually ride in.
enjoyed it!!

Nice!