I was corresponding with someone here about how to keep mast base pressure by using the front hand to sheet out (thank you, Sebastian K?rdel). I know that, functionally, it's the equivalent to sheeting out with the backhand - the sail pivots around the... ahem, balanced harness line.

Well, on a finned board they are equivalent but why does sheeting out with the front hand seem to me to work so much better on a foil. As I was writing, I imagined the actions and it struck me. On a finned board, small variations of downward pressure on the boom are inconsequential. There's too much else going on not to mention if you vary the length of the planing flat a few cm back and forth, not much changes. Or, if it does, the results aren't as drastic as scratching your nose on a foil seems to be.

I should preface this by saying that after years on finned boards of having an underhanded grip on the front hand, I adopted an overhand grip when foiling. That was a pretty big change in itself in getting more downforce on the boom.

When we sheet out with the back hand, we extend it (the back hand) further away from our body. The further the back hand is from our body, the less leverage we have to push down on it. Imagine pushing down on something right next to you, say an annoying tot's head, vs pushing something down that's at arm's length. So, if we sheet out with the back hand, it's not enough to keep the same "pressure" (really our effort) on the boom, we actually have to exert more force to keep the same amount of downward overall pressure on the boom.

If, instead, we sheet "out" by bringing the front hand closer, we actually increase our leverage to apply downforce on the boom and it's easy to keep the same overall downforce or even increase it in a gust.

I know it seems like a subtle distinction but when getting whacked by a big gust it's the difference in plowing through it vs having things go all sideways. Thoughts? Or should I go ahead and get the admins to delete this and save myself shame?

at 5:21

Seems to make sense. Confounding this is the tendency to load the foot with the corresponding hand.

So sheet in with front: tends to load front foot and drop nose.
Less mast base pressure from sail but more downward force on hand and push on front foot... At least that's what it seems

I rarely use any back hand on foil. My lines are setup balanced or even a little rearward. This keeps the sail upright, far away from the sailor and helps load the front foot.
Nothing but advantages from my perspective.

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Paducah said..
I was corresponding with someone here about how to keep mast base pressure by using the front hand to sheet out (thank you, Sebastian K?rdel). I know that, functionally, it's the equivalent to sheeting out with the backhand - the sail pivots around the... ahem, balanced harness line.

Well, on a finned board they are equivalent but why does sheeting out with the front hand seem to me to work so much better on a foil. As I was writing, I imagined the actions and it struck me. On a finned board, small variations of downward pressure on the boom are inconsequential. There's too much else going on not to mention if you vary the length of the planing flat a few cm back and forth, not much changes. Or, if it does, the results aren't as drastic as scratching your nose on a foil seems to be.

I should preface this by saying that after years on finned boards of having an underhanded grip on the front hand, I adopted an overhand grip when foiling. That was a pretty big change in itself in getting more downforce on the boom.

When we sheet out with the back hand, we extend it (the back hand) further away from our body. The further the back hand is from our body, the less leverage we have to push down on it. Imagine pushing down on something right next to you, say an annoying tot's head, vs pushing something down that's at arm's length. So, if we sheet out with the back hand, it's not enough to keep the same "pressure" (really our effort) on the boom, we actually have to exert more force to keep the same amount of downward overall pressure on the boom.

If, instead, we sheet "out" by bringing the front hand closer, we actually increase our leverage to apply downforce on the boom and it's easy to keep the same overall downforce or even increase it in a gust.

I know it seems like a subtle distinction but when getting whacked by a big gust it's the difference in plowing through it vs having things go all sideways. Thoughts? Or should I go ahead and get the admins to delete this and save myself shame?

at 5:21

Nice video. Now I am wondering if I am unconsicously doing this

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Grantmac said..
I rarely use any back hand on foil. My lines are setup balanced or even a little rearward. This keeps the sail upright, far away from the sailor and helps load the front foot.
Nothing but advantages from my perspective.

Same here
only time I ever use the back hand is to pump the board up in really marginal winds with small sails.
Otherwise it's all about balanced lines and front hand for flight control

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Paducah said..
I was corresponding with someone here about how to keep mast base pressure by using the front hand to sheet out (thank you, Sebastian K?rdel). I know that, functionally, it's the equivalent to sheeting out with the backhand - the sail pivots around the... ahem, balanced harness line.

Well, on a finned board they are equivalent but why does sheeting out with the front hand seem to me to work so much better on a foil. As I was writing, I imagined the actions and it struck me. On a finned board, small variations of downward pressure on the boom are inconsequential. There's too much else going on not to mention if you vary the length of the planing flat a few cm back and forth, not much changes. Or, if it does, the results aren't as drastic as scratching your nose on a foil seems to be.

I should preface this by saying that after years on finned boards of having an underhanded grip on the front hand, I adopted an overhand grip when foiling. That was a pretty big change in itself in getting more downforce on the boom.

When we sheet out with the back hand, we extend it (the back hand) further away from our body. The further the back hand is from our body, the less leverage we have to push down on it. Imagine pushing down on something right next to you, say an annoying tot's head, vs pushing something down that's at arm's length. So, if we sheet out with the back hand, it's not enough to keep the same "pressure" (really our effort) on the boom, we actually have to exert more force to keep the same amount of downward overall pressure on the boom.

If, instead, we sheet "out" by bringing the front hand closer, we actually increase our leverage to apply downforce on the boom and it's easy to keep the same overall downforce or even increase it in a gust.

I know it seems like a subtle distinction but when getting whacked by a big gust it's the difference in plowing through it vs having things go all sideways. Thoughts? Or should I go ahead and get the admins to delete this and save myself shame?

at 5:21

Very interesting how we old timers who have spent decades windsurfing have to unlearn certain types of muscle memory in order to foil. This is yet another example. Thanks for sharing the video; it makes sense, and I'll try it next time I'm on the water.

Select to expand quote

Paducah said..
I was corresponding with someone here about how to keep mast base pressure by using the front hand to sheet out (thank you, Sebastian K?rdel). I know that, functionally, it's the equivalent to sheeting out with the backhand - the sail pivots around the... ahem, balanced harness line.

Well, on a finned board they are equivalent but why does sheeting out with the front hand seem to me to work so much better on a foil. As I was writing, I imagined the actions and it struck me. On a finned board, small variations of downward pressure on the boom are inconsequential. There's too much else going on not to mention if you vary the length of the planing flat a few cm back and forth, not much changes. Or, if it does, the results aren't as drastic as scratching your nose on a foil seems to be.

I should preface this by saying that after years on finned boards of having an underhanded grip on the front hand, I adopted an overhand grip when foiling. That was a pretty big change in itself in getting more downforce on the boom.

When we sheet out with the back hand, we extend it (the back hand) further away from our body. The further the back hand is from our body, the less leverage we have to push down on it. Imagine pushing down on something right next to you, say an annoying tot's head, vs pushing something down that's at arm's length. So, if we sheet out with the back hand, it's not enough to keep the same "pressure" (really our effort) on the boom, we actually have to exert more force to keep the same amount of downward overall pressure on the boom.

If, instead, we sheet "out" by bringing the front hand closer, we actually increase our leverage to apply downforce on the boom and it's easy to keep the same overall downforce or even increase it in a gust.

I know it seems like a subtle distinction but when getting whacked by a big gust it's the difference in plowing through it vs having things go all sideways. Thoughts? Or should I go ahead and get the admins to delete this and save myself shame?

at 5:21

Very interesting how we old timers who have spent decades windsurfing have to unlearn certain types of muscle memory in order to foil. This is yet another example. Thanks for sharing the video; it makes sense, and I'll try it next time I'm on the water.

I think this explains why on freeride foils I tend to drop my rear hand and lean into the harness and just tweak with the front unless overpowered. Seems a lot more difficult to drop the front hand and just use the back hand but I also wonder if there's another technique or setup thing that I have wrong.

Interesting. Giving Sebastian's success in foiling, definitely not something to ignore. One peculiar thing is that sheeting out with the front arm can easily reduce mast foot pressure. One example is jibes on slalom gear, where leaving the front arm long definitely gives better jibes. But the difference is that the sail should ideally be fully depowered in the jibe, and sheeting out by pulling in with the front arm actually keeps more power in the sail, which moves your weight backwards ... when you should be standing balanced.
Similar arm movement, very different effect on control!

Front hand sheeting is very useful. You can see me do it in the Speed Video I did, just watch my front arm throughout... But Sebastian's explanation is much better!

And to Aero's point... back hand is vital to keep mast pressusre on. I often increase backhand pressure when overpowered, but use front hand and harness load to keep nose down.

Let me try to explain that. So on a reach fully commited to the windward rail, sail overhead in 'send-it' mode. Then an overpowering gust hits. I keep the body weight in the harness (upto 90%) and add a bit of weight to the back hand to drive the nose down. Then to help NOT accelerate I pull the front hand in towards me (brake as Seb says), and angle my body towards the nose a bit by swinging in the harness. This way I can stay commited, not slow down, but not speed-up too! With the new balance point, I can then accelerate a little more slowly, potentially opening the front hand of the sail, maybe dig the foil windward rail in deeper and make the gust mine.

Played with this same thought today on IQFoil gear. I was expecting 8 to maybe 12kts but the forecast was off of course . Looks like, according to the wind station there, a lot of 15-18kt periods. Maybe it was a few knots high, can't be sure, but I was definitely well powered.

Anyway, yes, mainly front hand support worked very well with weight fully in harness, staying well sheeted, both feet in straps. However, I do think that a lot of my struggles with foiling were having my lines just a bit out of tune. Been noticing that in those well powered gusts it was pretty undramatic as long as I had the outhaul decently tensioned, as I had gotten the lines much closer to balanced than I had them previously. Hiking out dealt with it. On one side I noticed they were slightly aft biased, which I corrected, but usually it looks like I have been running them front biased. Front biased with a 9.0 on a race foil was providing a lot of coupling between gusts and foil lift...

Now if I can just get bigger stones to stay in the rear strap when heading downwind. Tried a bit today but the big gusts were spooking me a bit off the wind. I did notice that I could do the pull up with the back foot and push down with the front foot to head downwind as Berowne noted in this going fast thread. I'm just still...not that fast.

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berowne said..
Front hand sheeting is very useful. You can see me do it in the Speed Video I did, just watch my front arm throughout... But Sebastian's explanation is much better!

And to Aero's point... back hand is vital to keep mast pressusre on. I often increase backhand pressure when overpowered, but use front hand and harness load to keep nose down.

Let me try to explain that. So on a reach fully commited to the windward rail, sail overhead in 'send-it' mode. Then an overpowering gust hits. I keep the body weight in the harness (upto 90%) and add a bit of weight to the back hand to drive the nose down. Then to help NOT accelerate I pull the front hand in towards me (brake as Seb says), and angle my body towards the nose a bit by swinging in the harness. This way I can stay commited, not slow down, but not speed-up too! With the new balance point, I can then accelerate a little more slowly, potentially opening the front hand of the sail, maybe dig the foil windward rail in deeper and make the gust mine.

Interesting thoughts. Seems like the front hand pressure AND position is quite important?In fin mode it seems pretty easy to keep front hand by harness lines and relax with straight arms. On foil, depending on gear, it seems to really change what's going on when you move your front hand forward vs. right on the harness lines.

We are overthinking this, I believe. Sheeting out with the front hand is "basically" the same as sheeting in the back hand since the sail rotates the same way in both instances. (Sail uprightness is another topic.)

The reason sheeting in (back hand pulling) prevents breaching is that it INCREASES mast base pressure. Instructors have been telling this to students for decades. Formula and slalom racers made a fine science of this.

In our sport (windfoiling), if a gust hits sheet IN to keep the nose down. Sheeting out will always lift the nose unless you are quick enough to compensate by weighting the boom more. This is all part of the "new" muscle memory we have had to change from finning.

I windfoil in the Columbia Gorge, which is the gust capital of the world. Sheeting in for gusts has become de rigeur here.

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segler said..
We are overthinking this, I believe. Sheeting out with the front hand is "basically" the same as sheeting in the back hand since the sail rotates the same way in both instances. (Sail uprightness is another topic.)

The reason sheeting in (back hand pulling) prevents breaching is that it INCREASES mast base pressure. Instructors have been telling this to students for decades. Formula and slalom racers made a fine science of this.

In our sport (windfoiling), if a gust hits sheet IN to keep the nose down. Sheeting out will always lift the nose unless you are quick enough to compensate by weighting the boom more. This is all part of the "new" muscle memory we have had to change from finning.

I windfoil in the Columbia Gorge, which is the gust capital of the world. Sheeting in for gusts has become de rigeur here.

I think you are misunderstanding us/me. We are reducing power by pulling the front hand towards us instead of releasing the power the way most windsurfers understand by pushing the back hand away. We are reducing the sail's AoA but still maintaining the appropriate amount of mast base pressure. Many people starting out on the foil have trouble in gusts because as they try to depower the sail, they inadvertently take some downward pressure off the boom which makes the board climb at the precise time they don't want that.

btw, sheeting in to increase mbp works to a point. At some point, there simply is too much power in the sail and it needs to get feathered. In the video above, Sebastian K emphasizes he does it, too.

Other people have gusts, too. Maybe not as big as yours but large enough in variations where one has to pay attention. I was sailing in no white caps to 30+ today.

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segler said..
Sheeting out with the front hand is "basically" the same as sheeting in the back hand since the sail rotates the same way in both instances.

It's only the same with respect to the sail movement, not with respect to forces on the boom (and therefore mast foot). To sheet out with the front hand, you pull, with the elbow pointing down somewhat. To see how this can increase mast foot pressure, consider how the arm movement is similar to a pullup.

In contrast, sheeting out with the back hand is often done by extending the arm, so that the elbow is pointing down less. So you push down less on the boom, and mast foot pressure is reduced.

Those are the typical arm movements, but other ways to sheet out are also possible. They include rotating the upper body; using the shoulders rather than the arms; and to consciously increase downward pressure on the back hand while extending the back arm. I'm sure some racers and experts are using these options, but the "pull with your front arm" is a much more natural movement. That means it's easier to remember and do when things gets hairy...

Good points, all.

I'm also playing around with the idea of shifting the sail forward and not sheeting too much so I can use the extra power and accelerate without breaching... but damn it takes commitment!

When I see a gust coming I move both hands back down the boom then bring the rig forward (to original hand position infront of me) to add mast foot pressure. Balanced harness lines work for me too. I aim to have the mast tall and sail sheeted in and that depends on speed and angle of sailing too.

Shifting hips seems to be the preferred method from watching PWA racing. Some leg/hip angles got pretty extreme during reaches. Sandusana people!