slake wrote: ↑Thu Mar 17, 2022 12:12 pmSand.....I meant sand and wrote file. Maybe I should have used the word 'fairing'!

Don't sand the foil...take a file and add a small bevel (~45 deg) to the bottom of the trailing edge of the HA195 stabilizer. A couple of passes using a file should work. I did this and the humming went away.

Or try this.

bwd wrote: ↑Thu Mar 17, 2022 1:02 pm Don't sand the foil...take a file and add a small bevel (~45 deg) to the bottom of the trailing edge of the HA195 stabilizer. A couple of passes using a file should work. I did this and the humming went away.

Well crap...I guess I will be fairing.

bwd wrote: ↑Thu Mar 17, 2022 1:02 pm Or try this.

Them things waterproof? Do I need a leash?

Can some confirm screws on an old "A System" fuse with an upgraded A wing/any mast A+ or not/TTF/stabilizer: The upgraded A wing has a 25 mm fore and 28 mm/barrel nut aft. The old fuse still needs 2x 25 mm to attach to a mast, right? The 28 mm screws seem to bottom out on the old fuse. There is an Armstrong video on this topic but he doesn't mention screw length with old fuses. I got a small parts box for all these screws, and want to avoid getting these 25 mm and 28 mm screws mixed up.

Here's the video:

The humming went away at 12.3 knots? That's like saying my wheel shake is gone in a school zone.

Max 14knots. He was avoiding a ticket.

Haha…ouch

If whistling bothers you for 2s then you need to see a therapist. 100m is a good test. Wish I could afford a gps. Or gas.

It's great if a file works, I have only sanded one foil setup (moses usually comes razor sharp on the TE), full 2000g and noticed what felt like less resistance (more of that 'nothing' the kitefoilers used to talk about). I'm think most guys, especially those with more money than time, shouldn't bother. Especially if you want to keep the resale value. But I enjoyed the process and hope to do a proper 2K spray and sand on all my foils.

I am looking for a bit of advice. I am 6 sessions into wing foiling and slowly making progress, I have had some "semi" controlled runs on the foil and am able to work on foot placement and balance.
My biggest problem at this point is whenever I am on foil I need to put apply a lot of front foot pressure and I still can't keep the foil from eventually breaching. I have moved the mast track all the way to the rear and moved both feet quite far forward on the board.
I have a Quatro Wind Drifter 115L with a Konrad 1600 foil set up. Do I think about shimming or is the over foiling due to bad technique?
Cheers
Jason

Technique always has something to do with it. You can't go by the quatro footstrap holes, I find they're placed more for neutral foils. By the looks of it, the konrad 1600 is a slow, high lift foil. Put your front foot where it needs to go.

Like I said, it's a slow foil, so ride it slow. Do this by sheeting out on the wing once you're up and only sheet in as much as you need to keep flight. Even let go of the back hand and just glide back down to the water.

The cheapest fix is to put a positive shim. Find a 0.5 degree shim and insert it so that it flattens the stabilizer. Not only will this give you about 1-2" of equivalent mast-back movement, but it the setup will be faster and pump better.

The next option is to buy a smaller stabilizer. I've found that, which can give you another 1-2" of mast-back movement. But it will be more twitchy and make things like learning flying foot switches a lot harder. This is actually the a good option for a cheaper "next step" feel than buying new front wings.

Depending on how much you weigh, you might need a different front wing. I'm about 100kg in the winter and can hold down anything (2400cm2), even in high winds. In the same conditions where I can ride a 1000cm2 ha. But I know lighter riders get overpowered, which makes a lot of sense. As we can put all that extra weight on the nose of the board, imagine what a 40lb weight on the front of your board. It's part of the reason Winddoc goes faster than BWD on the same gear. Extra weight equals high speed/lift control.

Do the shim thing first.

I've got the same board, but with a Moses 1100 foil setup. Also just taking first flights but found similar to you hard to keep nose down. I moved mast all the way back in the track which really helped. Played with shimming a bit, but felt really loose in yaw.

I've found I just have to concentrate on getting weight on front foot, especially when on goofy foot tack on my non-dominant foot. I also found the footstrap holes end up being well behind where I need to stand on the Quattro. There seems to be quite a big variance in board and foil brands and where the balance points end up so mixing and matching needs some tuning of mast and foot placement. You might also be experiencing what you think is overfoiling/breaching, but I realized was happening to me was try to pump onto foil too early (ie before attaining flight speed). I'd get big dynamic lift shooting the board up, but then unable to weight shift and recover a flight height before the foil stalled out and I crash down. So maybe try just planing faster before coming up on foil more gradually.

Hydrodynamically, shimming stabilizers is same as adjusting aircraft elevator trim, which is done dynamically varying with rider (plane) weight, flight speed, etc. The center of mass moment ahead of the neutral point determines longitudinal stability; which foiling is perceived as how 'pitchy' or stable the foil feels. As you move your body backwards toward the mast, you get closer to the neutral point (reducing what's called the static margin and reducing stability). Shimming the foil sets up what angle of attack the foil flies at, which also changes the overall lift and drag of the foil system. So shimming the foil to reduce the angle of attack of the stabilizer (rotating the leading edge of the stabilizer up toward the board, as the lift on a stabilizer is actually downward), is going to lower the drag and lift coefficient of the main foil, meaning you fly faster to generate the same lift. At the same time, you're reducing the moment of the stabilizer which your body mass is leveraging against around the aerodynamic center of the foil (~1/4 way along the main foil). This means you move your feet backward on the board and/or shift the net pressure on your two feet toward the rear foot. So overall, shimming changes your net stance, reduces the stability of the foil system and will lead to you flying faster all else being equal. Switching to a smaller stabilizer would have a similar effect. Foils and stabilizers all have different designs (e.g. foil camber, built-in relative angles of incidence, etc) affecting the 'feel' of a given system.

Of course all of this is my real problem; as an engineer I overthink as I try to fly!

Flight speed? Ever heard of step-off dock starts? Trust me, I have a lot of time on Sab gear (especially the 1100) and either your feet are too far back and/or your balance fore aft and technique need tweaking.

Likely your body is stiff and your pulling the wing toward you and following the momentum backward. Just like people learning to kite are always leaning back against the power on the waterstart. You need to be on your front foot more while pumping the hand wing and jumping your whole body forward and into the hand wing. Bringing the back foot a few inches forward for initial pumps will help too. If you have enough power to wheelie you have more than enough speed to pump up and sustain flight.

If you want to keep the quatro board, the 700hs fuselage significantly reduces the front foot pressure. You'll have to drill out the 1100. Or get the 399 tail, it's the go to for most moses/sab foils anyway. The 1100 can go much quicker than you think before getting overfoiled. I've actually only felt like it was too much lift in shoulder plus swell.

Gybing wingfoil.
Seems like first step it to learn how to ride switch comfortably. Switch is when you’re facing upwind with the wing off to your downwind side, correct? I’ve tried to start foiling in that position and it feels so unstable I can’t seem to get any speed as I struggle to balance.
Riding my Onewheel, always left foot forward. So that’s my preferred stance. Is that what I should keep trying? Trying to foil on starboard switch? Or something else I should do first?
I’m using a windfoil board, a Naish Hover 122. Would it be much easier if I picked up a wingfoil specific board?

Also, when you do gybe, do you centerline both forward and back feet? Or do you move your front foot from old windward to new windward when you sheet in on new side?

Gotta get my gybes down.

Winging, especially in lighter winds, is all about balance. The only way to get that is more time on the board.

Switch is right non-dominant foot forward. What you're talking about is toeside. You don't actually ever have to ride switch, gybing from heelside to toeside, never moving your feet. This will burn out one leg and arm more than making the switch. And while you can ride upwind toeside, you'll go significantly more upwind in switch.

The naish hover 122 looks like a long board. From my experience, when there's a lot of board in front of the mast, without a longer fuse and bigger foil to compensate, gybing is much harder. On the water balance is much easier on a long board, so even if you can't fly, it's good to taxi in switch and toeside for building those stabilizer muscles. As far as a next board goes, you already have a big board, so go for something close to your weight (with a wetsuit) in kg.

One thing a lot of beginners don't realize about switch is that the wing tends to sit further in the window due to the twisted body position. Try really focusing on pushing the wing back with your left arm. And sheeting hard with the backhand, more so than in a heelside stance. I notice my left triceps is much more sore after a lot of switch upwind riding. Usually because I'm in a situation where I don't want to risk falling by switching feet.

I personally only ride with gybe straps, so my stance is always offset. My back foot varies from closer to centerline on faster small foils, and toes closer to the rail on bigger foils. The nsi vee strap is lightweight, but not too grippy that you're locked in on a fall. Look for boards with a center hole that allows for vee straps.

Once you're able to gybe and ready to foot switch watch (or listen to) this interview with Gunnar:


I don't know exactly where in the interview, but he talks about a proper foot switch. Don't do the shuffle. If kitefoilers can step forward in one move on 400cm2 foils than so can we. I became much more consistent (especially at higher speed) once I switched to strap to strap foot switches, love doing them from switch to toeside right before a big swell, and gybe on the swell to help with any speed I might have lost on the swap.

I find riding toes to windward is useful after a gybe until you get your foot switches dialed. It buys you time to foot switch when you're ready or when the waves are right. I'm not comfortable riding toes to windward for an extended time.

Foot switches: My experience was that a larger board was easier to learn foot switches on a flying gybe because is was less twitchy/less responsive to shaky foot movement. When I switched to a smaller board, it took a session to relearn and refine my foot movement and positioning because little mistakes caused more dramatic board movement. When learning, larger was easier. I started on a ~6' 115l board (Thanks ULR!) and then went to a 5'4" 90l board. Can't comment on a 7'+ wing board - never tried one. I imagine if the taxi foot position is a lot different from the foiling foot position on a longer board that makes it harder. If the foil tracks are in the right spot, that shouldn't be the case.

I think of my foot switch as a quick bunny hop - pop the nose of the board up and a quick hop with the feet to put the new front foot in position first, then the rear foot lands at the back. I ride with my feet offset from the centreline. I find I don't have enough leverage on the foil to carve the board with my feet on the centreline.

I mentioned the size of the "sweet" spot for your feet in my earlier version of this post as a function of board size, but I think that might have more to do with the foil configuration (foil sizes and fuse length). As I've changed my foil configurations, I've had to relearn maneuvers as well.

Thanks. So, I’ll try taxiing toeside and try to get foiling from that point, try to get some runs, as step 1. Step 2, Once comfortable, attempt flying gybes from frontside to toeside. Step 3 get the footswitch down.
In the vid, about 30-35 mins is when Gunnar is talking footswitches.
Thanks again guys.

AJ, I'd skip step 1. If you are board on the water, a foot switch is easier, so starting from the water in an uncomfortable position isn't really necessary. Even on a partial flying gybe, if my board touches down, I take advantage of the additional stability of the board in the water, to switch my feet.