Hello! Advanced winger learning to DW SUP Foil.
Trying to understand shimming considerations for getting up on sup foil, specifically. Which is true (Generally speaking when shimming a setup otherwise balanced for wingfoil)?
Stabilizer Shim:
A: More shim (more downforce, more drag) makes it easier to get up since the board wants to come out (nose up torque).
B: Less shim (less downforce, less drag) makes it easier to get up since there is less drag, at the expense of pitch stability. So negative shim as much as you can handle to reduce drag.
Rake Shim:
A: Shim rear bolts makes it easier to get up since the angle of attack of the foil is steeper, which creates more lift at the slow speeds we are going when trying to get up.
B: Shim rear bolts actually makes it harder since the nose will be bogging down in the water.
Thoughts?
In my case, I have a Cabrinha H series mk2 1050, an 107L DWSUP and I’m finding impossible to flatwater start and very difficult to start on but the steepest wind swell. I’m getting pretty proficient at sup foil surfing and have a few DW runs under my belt where I’m on foil like 10% of the time. I’m fit, 150lbs, and experienced with watersports. My goal is to getup earlier and easier on this front wing.
I’m looking at ways to tune my setup… I have not tried it yet but received some rake shims. I’m thinking a bit of increased angle of attack (1 deg) will suit the low-speed sup foil getting up.
I’m new to sup downwinding and sup in general but a 1050 seems like a very small foil to flatwater start or even learn paddle up on swell. I myself am similar weight and am just starting to get consistent flatwater starts using a PNG1300 (1700cm) and only getting some flat water lifting from an ARTPro 1201(1300cm) but unable currently to pump out without immediately stalling.
What interested me also about your post is just this last weekend I tried a buddies Kujira 1440, and expected to be able to get reasonable results. It to me felt quite draggy and I could not get more than a tiny bit of lift with a lot of effort. He mentioned the Kujiras often need baseplate shim which was installed but I wonder if it may not have been right for my board and may have had the foil at too low an angle making flatwater much more difficult than if it had optimal angle, whatever that is.
Cool man, and yeah I know 1050 is small, for a beginner especially, but right now that’s the front wing I have so I’m trying to make it work. Also, I’m really dialed with it once I’m up, and especially for sup foil surf, I would be hesitant to size up to lose shredability.
Flat water start is not that important to me, I’m just looking for ways to tweak my setup for maybe a 10% gain in ease of start.
Regarding your Kujira experience. that’s exactly the type of puzzle I’m trying to solve… you could shim baseplate to reduce drag but then the foil has less angle of attack so you will need more speed for the same board angle… kind of a catch 22.