This is one of the best videos I’ve seen explaining tail shimming and tuning. The only thing I feel is missing is the effects of shimming on feel, pitch sensitivity, turning, and speed. Negative shimming may turn better and be faster but also pitch sensitive and harder to ride, etc.
Thanks, happy that it helps you! You're right, it's a fine line between lower drag and being too pitch sensitive when reducing angle on the stabilizer. You can be faster with more angle / a more draggy system because of better control and the ability to push harder. Of course it also depends on your riding level what's best for you personally. Better riders can get away with a more nervous setup and enjoy the extra turning it offers them. Lower level riders will be better off with a more stable system to unlock their best. Cheers, Klaas
Remember that this advice applies to stabilizers mounted on the board side of the fuselage. The effect would be reversed for a brand where the stabilizer is mounted on the opposite side.
Hi Jerome - Could you please tell me how much shim I should use to make the 216C feel like the older 215 from the Windsurf foil set? (To me the 216 looks and feels much flatter/pitchier.) Thanks. (I can 3D print any angle shim.)
Hi, the 216 stab has about -2.0deg AoA in the center, compared to -2.3deg AoA on the 215 stab. You should thus use a 0.3deg shim on the 216 stab to make it similar to the 215. The thick part of the shim should be on the trailing edge side.
I’m not sure I understand the front foot pressure concept. Doesn’t this just depend on where I’m standing? All foils generate more lift as speed increases. If I find the front foot pressure increasing too much doesn’t that just mean I’m standing too far back or the mast is too far forward?
All front wings will generate more lift as speed increases IF the fuselage stay at exactly the same angle of attack. Remember that we have not only the front wing generating lift upwards but also the stabiliser which is generating an opposite force and thus subtracting lift from the front wing as speed increases. We explain that in more details in our other video "foil basics" ua-cam.com/video/b_bL2ksu_kA/v-deo.html
If your front foot pressure doesn't stay similar if you change speeds (accelerate), but pushes your front foot up more and more and you have to bring your weight forward the faster you go, then you might want to try decreasing your angle of your stab with the use of a negative shim to keep it more balanced throughout the different speeds you're riding. Some riders prefer to have the "safety" of the front foot pressure building up, as it's usually more controlled at high speeds to have a bit of front foot pressure to push into. Play around to see what's actually faster for you and your level of riding. Hope this helps!
Great work guys! My question is : What effects does a negative Shims have while riding a wave? Example: if I ride a one meter wave without thickness and the foil tends to come out of the water, if I insert (negative) shim while riding the same wave will the foil tend to stay in the water longer? If so, will this happen at the expense of delayed flight departure? I hope I was clear
Hi, yes a negative shim could help you in that case, definitely worth trying it and check if it solves the problem you are having. One adverse effect from using a negative shim though, could be that your setup becomes too pitch sensitive. If that is the case, you might want to try a smaller size stabilizer without any shims. Lastly it could also be that the foil you are using is too big and generating too much lift once on a wave. If you give me you exact setup description and your weight, I might be able to have a more accurate tuning solution to your problem.
@@BonieuxJerome Thank you in advance for your availability but I just needed to understand how the shims work in the waves. Sometimes I find myself in the situation I described above and moving the mast is an increasingly delicate operation.
Great that you are doing this tech talk. I really appreciate all the infos about your equipment!
This is one of the best videos I’ve seen explaining tail shimming and tuning. The only thing I feel is missing is the effects of shimming on feel, pitch sensitivity, turning, and speed. Negative shimming may turn better and be faster but also pitch sensitive and harder to ride, etc.
Thanks, happy that it helps you! You're right, it's a fine line between lower drag and being too pitch sensitive when reducing angle on the stabilizer. You can be faster with more angle / a more draggy system because of better control and the ability to push harder. Of course it also depends on your riding level what's best for you personally. Better riders can get away with a more nervous setup and enjoy the extra turning it offers them. Lower level riders will be better off with a more stable system to unlock their best. Cheers, Klaas
Remember that this advice applies to stabilizers mounted on the board side of the fuselage. The effect would be reversed for a brand where the stabilizer is mounted on the opposite side.
Good point! We should have specified that in the video ;)
Hi Jerome - Could you please tell me how much shim I should use to make the 216C feel like the older 215 from the Windsurf foil set? (To me the 216 looks and feels much flatter/pitchier.) Thanks. (I can 3D print any angle shim.)
Hi, the 216 stab has about -2.0deg AoA in the center, compared to -2.3deg AoA on the 215 stab. You should thus use a 0.3deg shim on the 216 stab to make it similar to the 215. The thick part of the shim should be on the trailing edge side.
I’m not sure I understand the front foot pressure concept. Doesn’t this just depend on where I’m standing? All foils generate more lift as speed increases. If I find the front foot pressure increasing too much doesn’t that just mean I’m standing too far back or the mast is too far forward?
All front wings will generate more lift as speed increases IF the fuselage stay at exactly the same angle of attack. Remember that we have not only the front wing generating lift upwards but also the stabiliser which is generating an opposite force and thus subtracting lift from the front wing as speed increases. We explain that in more details in our other video "foil basics" ua-cam.com/video/b_bL2ksu_kA/v-deo.html
At 3:50 , instead of "as you accelerate" did you mean "when you are riding at high speed" ?
If your front foot pressure doesn't stay similar if you change speeds (accelerate), but pushes your front foot up more and more and you have to bring your weight forward the faster you go, then you might want to try decreasing your angle of your stab with the use of a negative shim to keep it more balanced throughout the different speeds you're riding. Some riders prefer to have the "safety" of the front foot pressure building up, as it's usually more controlled at high speeds to have a bit of front foot pressure to push into. Play around to see what's actually faster for you and your level of riding. Hope this helps!
Great work guys! My question is :
What effects does a negative Shims have while riding a wave?
Example: if I ride a one meter wave without thickness and the foil tends to come out of the water, if I insert (negative) shim while riding the same wave will the foil tend to stay in the water longer? If so, will this happen at the expense of delayed flight departure?
I hope I was clear
Hi, yes a negative shim could help you in that case, definitely worth trying it and check if it solves the problem you are having. One adverse effect from using a negative shim though, could be that your setup becomes too pitch sensitive. If that is the case, you might want to try a smaller size stabilizer without any shims. Lastly it could also be that the foil you are using is too big and generating too much lift once on a wave. If you give me you exact setup description and your weight, I might be able to have a more accurate tuning solution to your problem.
@@BonieuxJerome Thank you in advance for your availability but I just needed to understand how the shims work in the waves. Sometimes I find myself in the situation I described above and moving the mast is an increasingly delicate operation.