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Ah another one sees the light: the foil position for SUP foiling is relative to your center of flotation, here approximated via the sweet spot for the front foot while paddling for the Go Foils (instead of the handle for the Gong template), but the idea is similar:
www.standupzone.com/forum/index.php/topic,33427.msg376852.html#msg376852
Note also how recent Dave Kalama SUP foiling boards keep the mast more centered (compared to prone surf foil boards), hence keeping a significant tail part behind the mast. He cleverly adds tons of rocker in a kind of "whistle tail" to ease the pumping/rocking motion on takeoff, but does not move the mast back, to stay at the proper distance of the flotation center.
That's wack!
+1 I'm with JB and hate to burst your bubble Colas and you should have got a tape measure out before boasting about Beasho's post on the Stand up Zone on 25" is the magic measurement from centre of front foot to front bolt on the Tuttle , which it is on my Kalama 7-1 BUT that puts the back of my mast 17" from the tail. I also contacted Dave Kalama asked how he sets them and he simply said I measure from the tail. You previously mentioned that this board was set up wrong by Dave Kalama.
You also seem to forget I did set my mast forward on my Blue D-C 7-6 to test your theory and rode it like that for 6 months. I have just cut the boxes out to move them back to 21". It really did wack it's tail on pumping plus on steep take off's it was incredible hard to keep the foil in without standing way forward which is the last place you want to be on step take off's , but yes my feet didn't shift much on smaller waves but the one pro was far out weighed by the cons. Hence that's why I cut it out.
Yes I did watch the video and I have a lot of respect for Robert & Sam for their constant R&D and sharing it all with us with an impartial view.
Is this the table of measurements you are referring to as complicated ?
I for one value the robust exchanges between Colas and Piros.There is nothing worse than R&D occupying an echo chamber where the occupants
feel compelled to agree with one another.Congrats to both gentleman for their enthusiasm and passion!
JB
I was travelling and found an old Aeronautical engineering book "The Fundamentals of Flight."
This passage explains what is going on with regards to the balance point between the Center of Gravity (c.g.) and the Aerodynamic Center (a.c.) of lift. (This is a INDEPENDENT FROM COLAS OBSERVATION ABOUT THE CENTER OF FLOAT)
"The Airplane center of gravity must be close to the aerodynamic center or excessive moments will be created. The c.g. is usually within 10% of c (Chord Length) of the a.c."
Typically the Center of Lift is ~ 25% of the Chord Length, or wing distance from leading to the trailing edge. The GoFoil Iwa wing is ~ 10 inches. This would mean that the the Center of Lift is 2.5 " from the leading edge. What this also implies is that the center of gravity, your center of mass should be within 1 INCH to maintain Stable Flight "or excessive moments will be created" aka you will get thrown off the back of the foil, or be riding NOSE DOWN.
This is theoretical but starts to explain the Empirical sensitivity of the Foils to Front, and Rear foot placement. More importantly how specific the sweet spot is for stable flight.
When I measure everything lines up nearly perfectly.
I am riding with a 30" stance. The center point is very near, but slightly forward of the Aerodynamic Center of Lift. This is required for all aircraft to fly in a stable configuration. The moment caused by the center of mass being forward of the center of lift is countered with a downforce on the Tailwing. If you look at the GoFoil tail it has a reverse camber e.g. the Tailwing foil is flat on the TOP surface and curved on the bottom.
This may also suggest that there is a LIMIT to how short the "Dinner Tray" Foil-boards can go. It is probably no coincidence that the tiny Dinner Tray boards are ranging from 3' 6" to 4'.
My next observation is that this configuration is set up with the large Blue Tailwing designed for the IWA and Maliko 200. I haven't been able to get my smaller KAI Tailwing on this setup BUT maybe the smaller wing will allow for riding the IWA in larger waves.
Hypothetically the smaller Tailwing should impose LESS down force at speed reducing the Bucking Bronco effect felt when the IWA takes off in larger surf. Mmmmmmm?
Maybe Piros, the Hawaiians, COLAS or someone else has experimented with this potential combination.
Hypothetically the smaller Tailwing should impose LESS down force at speed reducing the Bucking Bronco effect felt when the IWA takes off in larger surf. Mmmmmmm?
Maybe Piros, the Hawaiians, COLAS or someone else has experimented with this potential combination
I know Dave Kalama in the early stages was using the old Maliko with the Kai rear wing with some success and this is where the IWA came from. We tried it here without much success as the rear wing was a bad fit. Also tried the Kai on the back of the new 200 just felt weird . The 200 is a slow wing with mega lift and I know the rear wing is there to create down force for stability but I argue that with GF rear wing tips facing down also creates drive and definetly creates more pump. So what I am saying is that by fitting a smaller rear wing it won't necessarily let you go faster but make you more prone to over foil. IMHO
Through tons of testing , towing and foiling on bigger waves , those big fat lipped GF's definetly have a lower terminal velocity compared to the super refined thin Lift Foils , I think this is far more relevant than shrinking the rear wing. Again IMHO....
My 49th foil session: (I now foil less than once a month).
My 3rd session on the new 400 euros Gong foil, really great (and ships worldwide, wink, wink :-) ), and the 13th on this 6'10" board.
Shame shipping is that steep, cause the foil price is great. How much lift do you think the 80cm Gong foil gives? I'm about 106kg and my Kenalu 775 Iwa doesn't really get me enough to lift off on smaller days. I'm hoping to find something with a little more power without going all the way to a downwind sized foil.
The waves were about 1ft 10 second when I was trying to foil. I was able to catch and ride these waves for about 100 ft, but not enough speed for lift off. I'm still a beginner, so maybe a more experienced person could have pumped on the board onto foil.
Exiled
Get a bigger foil. Even if it's downwind based.
Your water time and enjoyment will increase exponentially.
120 kg here. Surfing tiny waves every day in the Florida summer.
GoFoil Maliko 200 here. Pumpimg back out and getting multiple waves.
Turns just fine for what I need.
Dont waste time on a smaller foil if you dont absolutely have to.
No awards given for the smallest wing or the most pumps.
Bigger wings maximize the fun for big guys like us.
That might have sounded too strong.
But I started on a little GoFoil Kai, the a Pelican, then... and then... and then.
I wish someone had told me from the beginning to go straight toward a "downwind" foil.
There is no trick around it. You need large wings and a thick leading edge if you are a big guy and you want to get up and fly and stay flying on traditional foils.
It would have saved me a lot of time and money if I knew that early on.
No worries, it was well taken. I'm for sure picking up Ke Nalu's larger wing when it comes out, but they have been slow to market. I was just thinking that the Gong foil with its low price point could be a good stop gap and back-up foil. It feels like I'm just a little short of power on my current wing, so the hope was that a wing with an extra 10% of surface area might be enough to make the difference.
For another value option...
Robert / Blue Planet has a big Easy Foiler foil... He says its roughly between the Maliko 200 and the Iwa.
They seem well priced at $1,249 and full carbon.
I havent tried it yet. But Robert's Easy Foiler boards work great... And easy, as advertised. I bet his foil is too.
I just got a 2019 Naish XL today. It arrived... With no plate bolts. I have tons of plate bolts. But Naish uses smaller plate bolts than everyone. Argh.
So no flying it today... Or a few days. Until the bolts get here.
Anyway... Cant stop spending money on these darn things.
So far Maliko 200 gets the most use.
Yeah, if the Ke Nalu 970 ends up being too big I'll probably go over to the Blue Planet set up. It is good to see some in-between sizes showing up in different ranges, gives me hope I can get something dialed in eventually.
