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Huge drag at low speed

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Cefirmeza
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Huge drag at low speed

Postby Cefirmeza » Thu Jun 04, 2020 12:34 am

I am using a Lift 100 osprey wing with a long mast and I feel super draggy after take off and riding at low speeds.
It is like there is some air flowing underneath that feels kinda wobbly until I pump a bit of ride faster and it gets smooth.

I hate it because It holds me down during slow transitions so I have to keep decent speed so it doesnt hold me down.

What may be the cause and how to fix it? Maybe some small scratches at the wing tip is causing this drag or even greasy touch on the carbon?

I also use the slingshot hoverglide with standard wing and once up on the foil it is smooth no matter what speed.

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Peter_Frank
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Re: Huge drag at low speed

Postby Peter_Frank » Thu Jun 04, 2020 6:12 am

Cefirmeza wrote:
Thu Jun 04, 2020 12:34 am
I am using a Lift 100 osprey wing with a long mast and I feel super draggy after take off and riding at low speeds.
It is like there is some air flowing underneath that feels kinda wobbly until I pump a bit of ride faster and it gets smooth.

I hate it because It holds me down during slow transitions so I have to keep decent speed so it doesnt hold me down.

What may be the cause and how to fix it? Maybe some small scratches at the wing tip is causing this drag or even greasy touch on the carbon?

I also use the slingshot hoverglide with standard wing and once up on the foil it is smooth no matter what speed.

The Lift 100 osprey wing is a very low aspect wing.

The very nature of low aspect wings are, when you ride at higher angle of attack, they dont stall like higher AR wings do.

Because they make tip vortices, where the AOA gets lower from the tips, towards the center, meaning a lot more drag when in this state, but able to ride super easy and not stall, which is great for beginners and pushing hard in waves or in general, a lot easier ride.
Besides turning a lot faster because of the low AR.

BUT, these tip vortices when riding slow, and where some part of the wing might be semi stalled while it still rides on, gives some vibrations very often, at certain speeds (resonance).
It feels wobbly, growling sometimes, and eventhough no sound you almost feel you can hear the resonance, as it goes straight through the mast up your body - very noticeable.


What to do?

Well, I experienced this for the very first time, at a small but my first low AR wing in 2015.
Had ridden 3 higher aspect wings the years before that, and when I got this "Wave" wing, I though it was defect at first, whenever I carved around it had this wrong feel, sometimes also when starting at low speeds.

But after a while it totally dissapeared, meaning, my muscle memory got used to the new wing, and it never happened again.

This is very normal, when you get a new wing, no matter which, you (your body actually) can not utilize it fully, meaning not go as slow and low drag as it can.
It will come in time :thumb:

Of course, IF the resonance happens in a situation you ride very often, and it does NOT dissapear over time, you have to get rid of this wing, nothing you can do about it :roll:

The Hover Glide is a similar wing type I can see, but I have an idea you have ridden this quite some, or learned on this one, so built into your muscle memory now.

Then even a slightly different, or a lot different, wing, you have to ride quite a lot, till you can "max it out" in terms of riding slow in particular, but especially this vibration/growling which most low AR wings have at certain angles, will dissapear.

My advice is just to ride on, I think it will dissapear like magic :rollgrin:

8) Peter

Cefirmeza
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Posts: 82
Joined: Fri Aug 14, 2015 8:30 pm
Local Beach: Ceará - Brazil
Favorite Beaches: Ceará, Ibiraquera, Tarifa, Cape Town, T&C, San Andrés.
Style: Freeride
Gear: Slingshot RPMs and SST
Slingshot Hoverglide H5 / H3
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Has thanked: 11 times
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Re: Huge drag at low speed

Postby Cefirmeza » Thu Jun 04, 2020 11:00 am

Very nice explanation. Thank you Peter.


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