Having done a wee search first, I found a plethora of information about windfoil placement specific to various foil types/board footstrap arrangements, but I was hoping to just get ballpark feedback as to whether folks adjust their foil mast position depending on sail size only?
eg
bigger sails, move foil mast back a little bit
vs
smaller sails, move foil mast forward a little bit
or vv; something like that.
Do folks have any experiences with this they'd like to share? ??
FYI it is my wife's JP Freefoil 115 with a Sabfoil W799/W399 899 Fuse. Occasionally uses a JP GlideWind 11 Foil which has a shorter fuse.
No. From 5.8 to 3.3 on slingshot wizard 105 tuttle box.
5.7 to 3.7 on Tabou 97. Only change position for smaller stab moving foil mast forward.
I only move the foil mast for larger or smaller front wings. This is to keep the center of lift in the correct position between your foot straps.
I think the racers will move their sail forward when wind picks up and they don't wanna rig down.
But my experience is that for wave sails of 3.2 to 5.3 I can get away with same mast track position, However, if I go to a single cam freerace sail seems like it produces a lot more mast foot pressure than my wave sails so I feel like I want to move mast track back, but mostly I just slide my front foot a bit aft out of the strap.
As mentioned above different stabs or front wings will shift the center of effort of your foil, but I would much rather use a shim on the stab so that I can keep universal and foil mast in same place.
My guide would be. 
start with mast in the middle
if you struggle to get flying move it back 1cm at a time. 
if you struggle to keep the nose down move it forward 1cm at a time. 
if you are cursing and a gust hits and you accelerate and sheet in and the nose goes down move back 1cm or half. If you are cruising and constantly have to push on the back foot to keep the flight height move back 1cm
if you add a deposed shim maybe move back
if you add a power shim maybe move forward
if you are comfortable at 20 knots but want to go 25 consider moving forward 1cm
but also remember that;
1. body position
2. harness weight
3. boom height
4. foot weight
5 sail type
6. sail tension
7. harness line position
8. board speed
9. wind speed
10. chop
11. board roll (heel) angle
12.
etc all affect mast base position feel. enjoy this complicated sport.
Select to expand quoteberowne said..
My guide would be.
...snip...
etc all affect mast base position feel. enjoy this complicated sport.
@berowne, that is an awesome response, thank you.
We've recently moved it forward a fair bit, in increments, and the balance is getting really nice.
Generally no, once I found an "ideal" foil mast placement for a particular foil setup, I no longer changed that, and when changing the sails I played with the rig's mast foot placement instead. Bigger sails more towards the back, and smaller sails more forward in the track.
But then I discovered there are several ways to achieve the same result. On my board the mast track is very close to the front foot straps, and on such a setup it's actually possible to control how much weight the rig puts to the mast foot by simply leaning the rig forwards or backwards a bit. With the boards that have the mast base further away from the straps the effect is not as big, you would need much bigger sail movement to achieve the same result.
Here are a couple of examples, at first I though that with a light weight 3.0 rig (with a 310 cm super light mast) I needed to move the sail further forward (first clip). But later I discovered an even better setup (2nd clip). I moved the front straps 1 step forward, and after doing so I could use pretty much all sail sizes with the mast base in the same position (further back), and the foil mast in the same place as well.
3.0 m2
Select to expand quoteTaavi said..
Generally no, once I found an "ideal" foil mast placement for a particular foil setup, I no longer changed that, and when changing the sails I played with the rig's mast foot placement instead. Bigger sails more towards the back, and smaller sails more forward in the track.
But then I discovered there are several ways to achieve the same result. On my board the mast track is very close to the front foot straps, and on such a setup it's actually possible to control how much weight the rig puts to the mast foot by simply leaning the rig forwards or backwards a bit. With the boards that have the mast base further away from the straps the effect is not as big, you would need much bigger sail movement to achieve the same result.
Here are a couple of examples, at first I though that with a light weight 3.0 rig (with a 310 cm super light mast) I needed to move the sail further forward (first clip). But later I discovered an even better setup (2nd clip). I moved the front straps 1 step forward, and after doing so I could use pretty much all sail sizes with the mast base in the same position (further back), and the foil mast in the same place as well.
3.0 m2
3.5 m2, with a much more ideal setup.
4.0 m2, also with a new setup, distance between the front straps and the mast base pretty much as small as the board allows, the 3.0 m2 sail works wonderfully in the same position.
5.6 m2, with a different foil setup, but the same principle applies
Agree. I know I do a lot of that joystick thing when unhooked and on swell too. Not sure how much of it I do when hooked in.
Select to expand quoteTaavi said..
Generally no, once I found an "ideal" foil mast placement for a particular foil setup, I no longer changed that, and when changing the sails I played with the rig's mast foot placement instead. Bigger sails more towards the back, and smaller sails more forward in the track.
But then I discovered there are several ways to achieve the same result. On my board the mast track is very close to the front foot straps, and on such a setup it's actually possible to control how much weight the rig puts to the mast foot by simply leaning the rig forwards or backwards a bit. With the boards that have the mast base further away from the straps the effect is not as big, you would need much bigger sail movement to achieve the same result.
Here are a couple of examples, at first I though that with a light weight 3.0 rig (with a 310 cm super light mast) I needed to move the sail further forward (first clip). But later I discovered an even better setup (2nd clip). I moved the front straps 1 step forward, and after doing so I could use pretty much all sail sizes with the mast base in the same position (further back), and the foil mast in the same place as well.
3.0 m2
3.5 m2, with a much more ideal setup.
4.0 m2, also with a new setup, distance between the front straps and the mast base pretty much as small as the board allows, the 3.0 m2 sail works wonderfully in the same position.
5.6 m2, with a different foil setup, but the same principle applies
Thanks for that and the vids btw are awesome, you've got a beaut swell there. My wife's smallest sail is 2.9, then 3.3, 4.0, all combats, so comparable sizing. We're finally finding the sweet spot for swell riding and unhooked she somehow naturally leans the rig like in your videos. Great stuff !! Interesting how far forward that back strap is on your board but it's all relative to CoL plus riding style I guess.
Select to expand quotejksmurf said..
Thanks for that and the vids btw are awesome, you've got a beaut swell there. My wife's smallest sail is 2.9, then 3.3, 4.0, all combats, so comparable sizing. We're finally finding the sweet spot for swell riding and unhooked she somehow naturally leans the rig like in your videos. Great stuff !! Interesting how far forward that back strap is on your board but it's all relative to CoL plus riding style I guess.
Thanks. Definitely it's all relative to the riding style. Every design and configuration likely makes some compromises so it could shine for some type off riding.
