Author Topic: Are there any good, hydrodynamic reasons NOT to wing on a 90cm mast?  (Read 1733 times)

wingdingjoe

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Been kite foiling 4 years. Just beginning my journey into wing ding. Have several 90cm alu masts. Had been thinking about the 75 to 80 cm range on any new foil setup ive been researching. However my ultimate goal is to be able to just switch up the front wing to be able to change between a kite sesh and a wing sesh.

I understand that the "pumping up onto foil" dynamic is very different between kite and wing.. And ive yet to try winging on a 90cm mast.. However some videos of guys in big surf seem tu show them using 90s.

Any reason why pumping up onto foil might be EASIER on 75s and 80s or is just "convention" of wing surf at this point that everyone uses 75s?

Last question... Anyone with experience using the NEW 2020 FANATIC HA Aero foils?

Thanx and good winds to all!

Dwight (DW)

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When riding waves winging, you can carve rail to rail quicker on a short mast. Long will force you to make kite foiling type turns.


container

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Shorter mast is easier to pump, less drag due to the fact youre pushing less shit thru the water to start with, and even less drag cause the foils under less water (lower ambient pressure) at non foiling speeds

wingdingjoe

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Thanx guys.. Exactly the answers I was looking for. Love this forum.

Admin

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Does a tapered mast add to lift?  It feels like it does.  If there is added drag on the Axis 96 (over 76) that is not equaled or outdone by added lift then I am not feeling it.  A week of sessions on the 96 and it seems to take off easier, even in really light wind.  The overall freedom advantage is awesome.  It took me a day to adjust and 3 days to not want to go back.  This has me wondering about 100 plus.  Anyone tried 105 or similar?
« Last Edit: June 21, 2020, 03:20:04 AM by Admin »

PonoBill

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The tapered mast reduces drag a little, which increases speed a little. Speed is the most important factor in terms of it's effect on lift.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

Solent Foiler

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What about buoyancy of a large carbon mast? Presumably that might help in take off?
I'm 5'10", 65kg riding:
Gong Flint 5'6 95L
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Gong Pulse - 4m, 5m
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Admin

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The tapered mast reduces drag a little, which increases speed a little. Speed is the most important factor in terms of it's effect on lift.

But no direct lift from the mast itself?

container

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In order to have lift you must have a pressure differential, in this case on a vertical axis. if there was any adverse pressure around the foil (mast) it would have to be on on side or the other, which would make you crab sideways. Any increase in lift you feel will be due to a reduction in drag, thus increasing the efficiency of the foil

Admin

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In order to have lift you must have a pressure differential, in this case on a vertical axis. if there was any adverse pressure around the foil (mast) it would have to be on on side or the other, which would make you crab sideways. Any increase in lift you feel will be due to a reduction in drag, thus increasing the efficiency of the foil

Thanks Container.  It must be that. 

supnorte

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A lot of my friends have both the 75 and 90 cm masts. A 90 cm seems better for dealing with chop and goin high speeds.

Here's a friend of mine last weekend going full speed on a 90 cm mast (900 wing and standard fuse): https://www.facebook.com/axisfoilsportugal/videos/396500671275650/

Fishman

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The tapered mast reduces drag a little, which increases speed a little. Speed is the most important factor in terms of it's effect on lift.

But no direct lift from the mast itself?
Going thorough the water it'd have more resistance at the top, less resistance at the bottom. So possibly give it more of tendency to want to increase the angle of attack, giving the feeling of more lift.
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Admin

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George at Delta https://www.deltahydrofoil.com/ seems super knowledgeable so I had asked him this same Q about mast lift. 

Me: You seem super knowledgeable about all things foiling. Do we get any lift from the mast itself?

George: Very little if any.  Consider the leverage of the strut on the board,  if the strut were generating lift you would need to stand off the centerline to counter the torque. 
 
Me: Hi George, thanks so much.  What accounts for the difference in windsurf foiling?.  Is it the way the rider pushes horizontally against the strut (or the fin)?

George: There is a big horizontal force from the windsurf rig that must be opposed and the board is ridden relatively flat.    That is not the case with kites or hand held wings.  In windsurf foiling the strut generates lift and the straps are set near the rail.

I thought that was really interesting particularly in terms of stance and pre-take off board angle when winging. 
« Last Edit: June 23, 2020, 04:37:23 AM by Admin »

AlexFun

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Imo for open water foiling everything speaks for the 90  mast, more room for overfoiling in choppy waters.
But when you start launching in shallow places or riding small waves,  especially beach breaks the 75 mast has significantly more "room for error" aka hitting the sand bank or reef.

PonoBill

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Okay, I was completely out to lunch on this issue. I've had a 90CM mast in my truck for about 6 months and never really gave it a try. I'm an idiot. I had an awesome session this afternoon. Admin has been telling me that the 90cm mast is hugely superior to the 75CM, but I assumed he was just talking about overfoiling. Holy shit, I can't believe it took me this long to yank off the training wheels. It's pretty much indescribably better in every way--shocking. So much more maneuverable, quicker turning, forgiving. Overfoiling is the least of it. I'm getting very close to nailing switchfoot jibes with just this single change. Unbelievable. 

75CM is dead to me. I'll think of something to make from my shorter masts, but I'm not foiling on them again any time soon. Maybe for surfing, but not for wingfoiling.
« Last Edit: June 24, 2020, 07:41:59 PM by PonoBill »
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

 


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