Shimm vs Mast Track Placement

[Lamilu]

Can anybody explain in a few words…like to a 10 year old… …what is the relationship between shimm and mast track positioning…if any
For example…
I personally use W695+S399, all the way back, no shimm, I imagined all the way back would give me more board space to keep the nose down…and sinnce it worked fine from the start…didnt mess arround with it.
Now tried for the fist time in terribly gusty strong conditions a W799+S330 paired in HS fuselage.
Sabfoil recomends -1 degree Shimm to start (nose up shimm)…but hay…let me put it all the way back again and see if I can avoid the draggy unecessary plastic.
It works…but with less front foot pressure…sometimes verry little…
Does putting the mast forward an inch correct that feeling?
Mast position compensates for shimm?
Just trying to waste less effort in testing so many variables.
Thanks

[Peter_Frank]

No, mast position does not compensate for shimm.

Mast position is only relevant for your trim - do you ride with straps?
As if strapless it doesnt mean anything, you just position your feet accordingly.

Shimming can make a foil more neutral, or front foot heavy at higher speeds (nose down versus nose up shimm)

So because you havent shimmed the new wing, it does not tend to seek "nose up", especially at higher speeds.

If you like this feel, but want a tad more front foot pressure, move the mast a bit forward.

Peter

[airsail]

Moving the mast forward will increase foot pressure throughout the speed range.
Adding a stabiliser shim will increase foot pressure at higher speeds but little effect at lower speeds.

If you find your foil starting to dive at higher speeds, try adding a shim, but if your rear leg is constantly getting tired at all speeds, move the mast.

[Lamilu]

Moving the mast forward will increase foot pressure throughout the speed range.
Adding a stabiliser shim will increase foot pressure at higher speeds but little effect at lower speeds.

If you find your foil starting to dive at higher speeds, try adding a shim, but if your rear leg is constantly getting tired at all speeds, move the mast.

Perfect…the sensation was foil starting to dive at speed…very little front foot pressure.
Thanks a Lot

[pecmajor]

Moving the mast forward will increase foot pressure throughout the speed range.
Adding a stabiliser shim will increase foot pressure at higher speeds but little effect at lower speeds.

If you find your foil starting to dive at higher speeds, try adding a shim, but if your rear leg is constantly getting tired at all speeds, move the mast.

Hi Airsail,

I have the issue with my rear leg constantly getting tired at all speeds. I am a beginner who can say up on foil both directions forever only stopping to turn due to rear leg tired, still need to get in the water for turns. My buddies also tell me I am constantly riding with the nose of my board too high and board not flat. Do you think moving mast forward will help my rear leg issues and perhaps help me ride the board flatter.

[airsail]

Moving the mast forward will increase foot pressure throughout the speed range.
Adding a stabiliser shim will increase foot pressure at higher speeds but little effect at lower speeds.

If you find your foil starting to dive at higher speeds, try adding a shim, but if your rear leg is constantly getting tired at all speeds, move the mast.

Hi Airsail,

I have the issue with my rear leg constantly getting tired at all speeds. I am a beginner who can say up on foil both directions forever only stopping to turn due to rear leg tired, still need to get in the water for turns. My buddies also tell me I am constantly riding with the nose of my board too high and board not flat. Do you think moving mast forward will help my rear leg issues and perhaps help me ride the board flatter.

You should have no rear leg pressure, definitely move your mast forward. As your only learning I doubt if your getting a lot of speed so stabiliser shining won’t be an issue, yet.
If the board seems nose high, don’t worry about it, better than nose low as touchdowns will be easier to manage. You probably can’t feel it anyway. Just work on getting the foil more balanced, getting rid of the rear leg pressure.
A mate of mine rides with a lot of front leg pressure, so much that many others would struggle riding his foil. But he’s into interesting tacks and gybes, that front foot pressure allows him to almost dance around the front of the board.

[pecmajor]

Thanks for the advice airsail! I will move mast forward and see how it goes.