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JB said..mcrt said..
To define this speeds* in a different way:
-Stall speed is where flow separation happens,you loose all lift and drop.
-Minimum sink ,just a little faster than stall.If you had 1m of mast above the surface slowing to minimum sink will give you the Longest Time possible before touching down.Could be used to wait for a chop behind you?.
Problem with anything below max L/D is drag increases very sharply so you better have some horsepower in your sleeve (wing,pump,chop) or you are toast.
-Maximum L/D or Best Glide: faster than min sink, with the same 1m of mast above surface this speed will give you the Longest Distance before touching down.I think when pumping we tend to stay at or above Max L/D as it feels lowest drag with good handling,anything below gets very hard to accelerate out of,like getting in a hole,and kind of mushy handling.
If you were towing behind a jetski this would be the speed at which you feel less pull on the rope
*All this speeds are in fact AOA's.They only are fixed speeds at a constant load on the foil.
Change the riders weight,carve a turn or add any up/down acceleration and the speeds will change...but the AOA's at which you get them remain the same for a given foil.
Yep, it is very interesting. I look at the Sink speed giving you an idea of what foil you can get away with at what speed. Obviously we don't know the numbers or have the controlled environment to properly test. Glide ratio is definitely the speed were I think you foil is most efficient, add a tiny bit of power and you what I call "PRIMED" or as some call it foil plaining. Agree, once you go below Sink and towards the theoretical stall, everything gets heavy.
Rider weight, board weight, foilsetup all affect these, but it is an existing terminology to help understand what is going on. Particularly when picking foils. Would be good if foil brands listed the actual scientific Stall, Sink and Glide speeds so we could compare and understand further.
I would really like to know the speeds too but it is a can of worms.
It would be helpful only in comparing foils before buying, but really hard to get significant data.
Even with the same brand using the same testing method you would probably end up with numbers so close together for their models/sizes that they would be confusing.
Add that the speeds will change for every rider weight, that Stab config will significantly affect best L/D and then mix in other brands :) .Mayhem.
I think towing on a calm day can get ballpark results for Vstall and VmaxL/D of your setup/weight but i have never tried it. Once you own the foil you are going to feel this speeds anyway,numbers will be irrelevant.
Thx for the DW tips, it is really hard to write about this but it helps!.
I definitely fall into the trap of going for the big rides when Downwinging,on the other hand it is fun and having the wing to keep going means no price to pay.
Sup DW is very tempting ,i have not tried it yet because i know it is going to be exhausting,humbling and frustrating beyond belief.
You guys make it look so easy, honey trap :)