Forums > Kitesurfing Foiling

Shim specifics

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Created by AquaPlow > 9 months ago, 15 Nov 2018
AquaPlow
QLD, 1051 posts
15 Nov 2018 10:10PM
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I am plannng on putting a shim on my stabiliser while I learn.
I was thinking using various thicknesses of O-rings.
This is will be trial and error... In search of a short cut
What should I be aiming to achieve?
A 3 degree angle change less or more?
I realise that the length of the fuselage on a different setup to mine will be a factor but some knowledge will be better than my vacuum
So, can anyone who has done this fill me in on what you used and how you setup each change or did you trial and error?

Thanks
AP

Kamikuza
QLD, 6493 posts
16 Nov 2018 12:33AM
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I think it's Alpine does stock shims in 0.5, 1, 1.5 degrees ... so 3 degrees is huge.

Assuming your foil is actually "trimmed" for neutral to begin with
then
if you put a "shim" under the rear bolt of the stabilizer
you're going to:
Increase the effect of the stabilizer. And all that implies ...

You're (most likely) going to experience:
Increased front foot pressure
Draggy feeling from the stabilizer
Lower top speed
More aggressive nose-up attitude at low speed, especially before a stall
Instability due to improper fore/aft balance.

Best thing IMO you can do is trust the foil designer and leave the shimming alone. I really think they're either a crutch for a crap design or they have a very specific purpose for a very specific user ie. not 99% of riders. And yes before anyone asks, I've played with shims too.

Oh, if you're going to shim the mast, that would be a different thing. Pretty sure all you're going to affect is the angle of the board to the water ... but don't quote me on that.
You should also assume that if you have a matched board/foil set, then the strap holes are about perfectly centered for the foil and any issues you have are your own lack of experience. You can correct that deficiency by ... getting out on the water and putting the hours in.

If you can adjust the mast in the rails, start with it moved back some, if not all the way (depending on the foil type).

If you can't adjust the mast, move the front strap(s) forward as far as they'll go, and aim to put your back foot in the center or slightly forward between the strap holes.

When you can ride some, pay attention to feedback from your feet.
Should really feel equal pressure between front and rear when riding. If you have to lift your front leg or there's too much pressure on the rear foot to keep foiling, move the foil forward in the rails -- 1cm at a time.
Should feel silky smooth, no "rumble" from the foil, which would mean there's drag or turbulence down there, most likely from the stab not being neutral.
Trim shouldn't change as your speed increases, without a change in your balance.

You need to ride at the cruising speed of the foil, which will feel faster than you've done on the TT or directional before. Trying to go slow is like trying to ride a bicycle very slowly -- you have to work hard and fight to keep balance the whole time. Easier to go faster, so the gear balances itself. Honest.

airsail
QLD, 1241 posts
16 Nov 2018 5:04AM
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Just use a stainless washer, put it under the front of the stab screw. This will hold the nose down, and help stop the bunny hopping beginners often get. Once your comfortable skipping along on the surface without getting too much height you can remove the washer and learn height control.
Moving the mast to the rear of the tracks has a similar effect.

RAL INN
VIC, 2880 posts
16 Nov 2018 7:07AM
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Sometimes the best shortcut is to stop looking for shortcuts and focus on the task at hand.
if the task is to , say, stop the bunny hopping/ porpoises. Then this is caused by a rhythm of Lift-stall-lift
too much Aoa at time of lifting up on to foil. The focus for this is to build more speed before lift

warwickl
NSW, 2173 posts
16 Nov 2018 7:39AM
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Select to expand quote
AquaPlow said..
I am plannng on putting a shim on my stabiliser while I learn.
I was thinking using various thicknesses of O-rings.
This is will be trial and error... In search of a short cut
What should I be aiming to achieve?
A 3 degree angle change less or more?
I realise that the length of the fuselage on a different setup to mine will be a factor but some knowledge will be better than my vacuum
So, can anyone who has done this fill me in on what you used and how you setup each change or did you trial and error?

Thanks
AP


Before anyone can advise you we need to know what equipment you have including picturers of your current set up.
This topic has been discussed many times with many conflicting views. Naturally I know I am right.
When advice is given to shim we need to know if your rear wing is on top or under the fuselage for example.

bigtone667
NSW, 1502 posts
16 Nov 2018 9:51AM
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Select to expand quote
AquaPlow said..
I am plannng on putting a shim on my stabiliser while I learn.
I was thinking using various thicknesses of O-rings.
This is will be trial and error... In search of a short cut
What should I be aiming to achieve?
A 3 degree angle change less or more?
I realise that the length of the fuselage on a different setup to mine will be a factor but some knowledge will be better than my vacuum
So, can anyone who has done this fill me in on what you used and how you setup each change or did you trial and error?

Thanks
AP


The O-ring is quite an interesting way to do it. I suspect you will end up with a looseness in your ride as result of certainly amount of flexibility remaining in the rubber even after you tighten it down.

warwickl
NSW, 2173 posts
16 Nov 2018 9:53AM
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Naish do not have shims instead they provide an easy adjustment by simply loosen the bolt and tilt back wing noting position to yellow line.
This back wing (stabaliser) is on the bottom of the fuselage some other foils it's on top.

Fly on da wall
SA, 725 posts
16 Nov 2018 12:02PM
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Select to expand quote
RAL INN said..
Sometimes the best shortcut is to stop looking for shortcuts and focus on the task at hand.
if the task is to , say, stop the bunny hopping/ porpoises. Then this is caused by a rhythm of Lift-stall-lift
too much Aoa at time of lifting up on to foil. The focus for this is to build more speed before lift

Dam straight..
Good advice here, I'd listen carefully.
Unless you have a foil that uses shims, you don't need them just time on the foil. Do foil academy to get yourself programmed as to how to foil step by step..

warwickl
NSW, 2173 posts
16 Nov 2018 2:01PM
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Select to expand quote
Fly on da wall said..

RAL INN said..
Sometimes the best shortcut is to stop looking for shortcuts and focus on the task at hand.
if the task is to , say, stop the bunny hopping/ porpoises. Then this is caused by a rhythm of Lift-stall-lift
too much Aoa at time of lifting up on to foil. The focus for this is to build more speed before lift


Dam straight..
Good advice here, I'd listen carefully.
Unless you have a foil that uses shims, you don't need them just time on the foil. Do foil academy to get yourself programmed as to how to foil step by step..


Do not go fully with that logic, however, agree with the time on the foil part and the how to bit.
My view and experience
* If people have a closed mind to experiment then there would be no progress, so no new design foils etc
Trying a shim is simple so why not try, if no go then nothing lost.
* My experience with Zeeko foils - with the standard freeride blue/white foil wing it worked well with out shims. How do I know this, because I tried shims and it worked better without shims. I purchased the optional Carver wing and found it a little odd even after a few sessions. I added a ss washer, instant improvement in stability and overall performance. Same board ie Shinn Jackson in all cases.

Several brands that once did not provide shims or other aoa adjustments now do.
Guys who race often shim, sand etc to get the most out of their foil.
My general comment and not directly at you -
Have a closed mind to experiment, it is your choice but do not put restrictions on others.
Make statements based on ones own experience but not on just what one thinks. Encourage others to experiment, safely of course.

AquaPlow
QLD, 1051 posts
16 Nov 2018 6:46PM
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Thank you all..
There are lots of references to doing the shim but not detail of design.
I have heaps of ss washers they looked a bit harsh but good to know .. will give this a crack..

The master of homemade - Plummett - referred to gaffa tape in one post mmmm. Got to admire the home builds..
There is a really good example of terrific but still basic carbon foil DIY build in the Windsurfer foiling section (If I loose or bust this weapon I will definitely try this ).. JIC Scroll down to the DIY windfoil bit www.seabreeze.com.au/forums/Windsurfing/Foiling/Foil-wing-build

As usual the best comment is U need more time trying.. ahhhh!!

The last few times I have been out with the foil my 12m Reo has been falling out the sky or boarder line (red arrow days are
resident a lot recently)

Last time = borderline conditions and I found foot position (rear) too prone to moving too far back and was bronco'ed a fair bit.

So the combination of big kite and pendulum board... It is my problem to solve, basically I have traded an easy handling board (so when you are handling it) with a get up and going learners bouyant platform (re-purposed Sector 60).
So its table manners are nothing like the videos.

I am fixing 3 things - dial the kite size down (poor low wind smaller kites in the inventory), shim the lift down. Plus making an EVA back foot stop (a WIP).


I did a meniscus mucking about 2 up on a TT with one of my kids - all good now but straps are out.
I have SS foot hooks on the front. (Profile has a couple of photos)

I need to maximise the return for effort each time I get out there!!
FWIW I like the Progression Videos but they are not free.

Duke's comments about snowboarding in powder - yaaaahhh bring it on..
At this point I wish I could say that Eppo had stole my thunder re his delightful Axis (Glitter fanboy joined at the hip with Edging froth!!) stoke post in the equipment review..

Some major home renos are proving worthy downtime distractions till she blews...

Cheers
AP

Kamikuza
QLD, 6493 posts
16 Nov 2018 9:17PM
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You only really need hooks/straps in the beginning for water starts (or if you're lazy). About session three I went over and got stuck in the rear strap and tweaked my ankle ... then I took it off and haven't had one since. I've been over the front a few times, but they don't seem to hold and twist anywhere as insistently as a rear strap does. For me, anyway.

I like those blocks, good idea. Might prove to be stronger and just as effective as hooks too -- and less chance of snagging lines. A lot of guys are breaking those hooks ...

You want kite power in the beginning. You need to be able to start with low-powered kite work (shallow dips into the power zone) then just park it and ride, concentrating on the board. If you have to concentrate on the kite flying, you'll have too much of a hard time. If on the beach, you can park the kite at 11 or 1 and keep it there easily, then you're probably ok to go. The other one is, if you can't (self- or re-) launch the kite or body drag, you're not going to have much fun.

Just like snowboarding deep, dry powder. But different

You want to use board speed to foil, not rear foot pop. Watching the learners here, the thing they are all failing to do is ... go faster. Get the speed up, the foil will fly naturally and then aim to keep it just a couple of inches above the water. If it starts coming up, reduce power and speed (bear off) and let it drop.

No idea what your spot is like, but if you want to maximize results, you gotta get as far from the beach and shallow water as possible, then spend an hour getting back. Get someone to ride your foil way the hell upwind and follow them on a TT or directional then swap, or get a boat ride out. You want like 500 to 800 meters of deep enough water. Assuming it's on-shore wind, of course



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"Shim specifics" started by AquaPlow