Sorry to correct You again. But in my opinion You are still wrong about the shims. The shims do not change the angle of attack on the frontwing. Ist is just about the downforce of the backwing.
+ shims create more angle of attack on the backwing, so more downforce on the backwing, what generates more pressure on Your frontfoot (board is pushed up against the front foot, so more lift). Think of the mast as the axis of rotation.
-shims create less lift. In theory this flatter backwing is faster, but You need a certain amount of downforce on the backwing to stay in control.
it works like this:
Select to expand quotecad184 said..
Sorry to correct You again. But in my opinion You are still wrong about the shims. The shims do not change the angle of attack on the frontwing. Ist is just about the downforce of the backwing.
+ shims create more angle of attack on the backwing, so more downforce on the backwing, what generates more pressure on Your frontfoot (board is pushed up against the front foot, so more lift). Think of the mast as the axis of rotation.
-shims create less lift. In theory this flatter backwing is faster, but You need a certain amount of downforce on the backwing to stay in control.
it works like this:
Thanks for clarifying cad184! Happy to be corrected here.
I'm no hydrodynamics engineer and I'm new to foiling. It's great to get a more experienced description over my basic 'feels' description. Thank you!
adding to what Cad said: I believe the degrees in the shims is in relationship with the front wing. So, zero degree means the front and back wing are at the same angle. Positive shim degrees means that the stab has more angle of attack so you have more power. Negative shim degrees mean that the stab has lees angle of attack so there is less drag (more speed but less power. remember that when you are looking at your foil while the board is on the ground, you need to flip/think about everything upside down for it to make sense.
Just to chime in as someone was asking for feedback on the M mast version. I have the M mast and alu fuselage nad all i can say is it is still very fast and stable. Cant realy compare to the S mast as have not tried it, but for pure speed it was stated that the S has 1-2 knots of top speed over the M mast. Now if that means that the S mast has a top speed of 37kt the M mast should be around 35kt i have no idea but its still plenty fast for me, and the issue is not in the gear but myself. So far my top speed is 28.5kt with the 550h wing. The wind was around 15-17kts so there is definitely room to go faster but i also need to grow bigger bals :D
Select to expand quoteKarbonko said..
@Karbonko
good speed, what shim setup and mastbase position are You using? I use +1 with the 195 backwing and +1,5 with the 160, but will try the +1,75 next time.
Select to expand quotecad184 said..Karbonko said..
@Karbonko
good speed, what shim setup and mastbase position are You using? I use +1 with the 195 backwing and +1,5 with the 160, but will try the +1,75 next time.
My board is the 91 patrick comp v2. Mastbase set in the midle of the track. Dont know what that measures to. I use around 3,5 degrees of rake. Less if its flat. Will hovever also get a 85 for next season as i feel the 91 gets a bit uncofortable when the wind picks up. Could be just the back strap position.
With the 100V2 fuse i use the 750 front wing as my light wind settup with the 195 back and a +1 shim. I can get this settup to around 26 knots, After that the lift starts to get uncomfortable, but im sure someone better could make it go faster.
With the 550 i use the 160 back wing with +1.5 shim. I have tried the +1.75 shim, but it feels to much when going fast.
