Forums > Windsurfing Foiling

Foil Board Mast Track Position

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Created by Poimax05 > 9 months ago, 18 Jul 2020
Poimax05
46 posts
18 Jul 2020 7:06AM
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Hi,

I just bought a JP freefoil 130, and I started to take some measurement to compare it with my formula board to define the foot strap position and mast track position

I sail with a Moses Vento Foil (790 mm wing) , and as per the recommendation from Sailworks, I had adjusted the mast track to 43-43" from the front tuttle screw; it was at the extreme back of the track on my formula, and it worked quite well, Very balanced for my 6 sessions so far on the formula board

I also see that 42 inches seems a starting point for the Infinity 76 (which is very similar to my wing)

However, on my new JP freefoil, the mast track is so much at the back of the board that the front of the track is at 40" from the front tuttle screw... I did not expect that at all! So I cannot replicate my adjustment.

This is supposed to be the perfect board for the vento according to 2 shops.

Is anyone running the infinity 76 or Vento 790mm with a mast base in the 36-40 inches range from the front tuttle screw ? Does it work well ?

I am just wondering what should be my starting point for the mast base, to find the right adjustment with less iterations. It seems conterintuitive to start completely at the front of the track.

Thanks for your input!

Subsonic
WA, 3118 posts
18 Jul 2020 10:04AM
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I'd put it in the middle and try it.

keep in mind that the jp freefoil Is a totally different board to the formula board. The footstraps are in a different place, its quite possibly got a longer nose on it than the formula board. And the free foil is more than likely designed with wave sails in mind. all of this is generally taken into account when they decide where to put everything, along wIth test rider feedback.




azymuth
WA, 2031 posts
18 Jul 2020 10:34AM
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Select to expand quote
Poimax05 said..Is anyone running the infinity 76 or Vento 790mm with a mast base in the 36-40 inches range from the front tuttle screw ? Does it work well ? I am just wondering what should be my starting point for the mast base, to find the right adjustment with less iterations. It seems conterintuitive to start completely at the front of the track.


I run my base as far back as it can go in the Wizard 105 mast track with the Infinity 76 in light wind - 39 inches to front Tuttle screw.
Works great to get up on foil.

In stronger winds, I move it forward 2-3 inches with the 76 - but often leave it at 39 inches when changing to the Infinity 65 wing.
So you might be fine with your more rear-set mast track - a lot depends on how much lift your wing has, your weight and whether you sail over-powered or tend to change down sails.

Samkyo
88 posts
18 Jul 2020 2:10PM
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Hello Azymuth,

with your mast foot at 39" what's your footstrap position?

powersloshin
NSW, 1684 posts
18 Jul 2020 4:26PM
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Instead of asking for measurements I would just go out , change one thing at a time and try and figure it out by myself. Something that works for someone not necessarily is the best for someone else

Grantmac
2068 posts
19 Jul 2020 1:00AM
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I preferred 39-40" on the I76.

LeeD
3939 posts
19 Jul 2020 1:18AM
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Ditto Powersloshin...
3 Naish foilers here, weight within 10 lbs., totally different everything.
All intermediate.

PatK
303 posts
19 Jul 2020 1:37AM
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Have a look how much rear Balz Muller sets his mast foot. He is riding with moses 790

thedoor
2291 posts
19 Jul 2020 3:41AM
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Yep foil mast to sail mast measurements depend on footstrap position, foil size, board speed, rig size etc

I run my i76 at 35 inches and its great.

I second the idea of not bothering to measure. I would just go with front strap middle, mast track all the way forward and no back strap

If lifting way to easy scoot front strap forward all the way, If not lifting at all start scooting mast track back. Ideally you are at a launch where it is easy to come in and adjust and go back out in the same conditions.

The goal IMO is to having things set up with a front foot heavy stance.

Poimax05
46 posts
21 Jul 2020 5:54AM
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Thanks for the advices guys.

Off course, experimenting is best, but let's be honest, it's a real pain to get my foil and rig out of the water for mast base adjustments.

I am wondering if there is any possibility or tricks to adjust a mast base in the water. Maybe a mechanical mast base ?

I had a nice session yesterday in 10-25 knots wind and 4.7 sail.
So I used about 38 inches front the front tuttle screw for the mast base (3/4 of mast track toward the front) ; and then I had to lower my boom which was way too high (makes sense ; my rig was probably raked back when I was using my formula ; with mast track back, I am more upring, and need to bring the boom down).

I was pretty balanced in flight, with a front foot tendancy. Board flies nicely, very low swing weight, wow!

With that said, I did not feel I was efficient for take offs. Board was somehow not reacting well to sail/foil pumping . Things seem to have gotten better when I tried to move my foot at the extreme back while pumping (more than on my Formula).

I am under the impression that I should move the mast track further back (and maybe front foot strap slightly) to help with the take off.

Altough I am fairly convinced this will really help, I am a little concerned this will make my riding very front foot heavy. I could be wrong. Anyone has faced this dilemna ? Balancing feet in the air, while maximizing ease of take-offs ?




LeeD
3939 posts
21 Jul 2020 11:00AM
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Sit on your board, facing downwind. Kick to move sail to either side.
Pop off the mast base.
Now twist and slide front or back.
Lift mastbase to deck of board.
Align pins and slip it on.
Easy, even a 71 year old can do it within 3 minutes.

utcminusfour
664 posts
21 Jul 2020 7:23PM
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I run the sail mast base about 34" in front of the forward tuttle boltwith the Moses 790.

Poimax05
46 posts
21 Jul 2020 9:44PM
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@ LEED : Do you use a 2 BOLT mas bast or mechanical base ? I use a single bolt tendon base (and us cup) , and what you are asking will not work so well ; very tough to reconnect the extension with the mast base in the water.

Especially if i have to move the mast base, I have to do it in relatively deep water (so the foil does not hit the bottom) as I stand on the board.

I think with a mechanical mast base which should make the sail much easier to reconnnect, that should be doable near the shore (but with sufficient depth) without much risks.

What do you think ?


PatK
303 posts
22 Jul 2020 12:17AM
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I ask some other mate to hold my board for me while adjusting the base position. Thats the easiest way for me.
Watch this vid from 3:20 for the position:

LeeD
3939 posts
22 Jul 2020 12:42AM
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Mech, rubber, or tendon makes little difference. You gotta SIT on the board, then it's easy to plug in, after aligning the pins.
Even my girlfriend can unplug and adjust, then reply in windswell under 18".
Obviously, impossible in breaking waves over a meter.

LeeD
3939 posts
22 Jul 2020 12:46AM
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And hard when wind is over 30 knots.

boardsurfr
WA, 2321 posts
22 Jul 2020 2:09AM
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Select to expand quote
Poimax05 said..
I use a single bolt tendon base (and us cup) , and what you are asking will not work so well ; very tough to reconnect the extension with the mast base in the water.

Especially if i have to move the mast base, I have to do it in relatively deep water (so the foil does not hit the bottom) as I stand on the board.

I think with a mechanical mast base which should make the sail much easier to reconnnect, that should be doable near the shore (but with sufficient depth) without much risks.

What do you think ?


Check out the new mast base from Chinook that has a tendon as well as a mechanical part. It's made specifically for foiling and makes connecting the rig a lot easier. chinooksailing.com/collections/bases/products/1-bolt-pro-flex-mast-base-us-base-cup

segler
WA, 1623 posts
23 Jul 2020 11:47PM
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Remove all footstraps. Start with 42" in front of the front screw. Foil this way ten times. Yes, ten--as in 10--times. it will take you that long to get everything figured out. There is a lot of muscle memory to develop, and foiling is a LOT different from fin sailing since you have this little thing called PITCH to figure out and get under control. If you haven't noticed, your stance is very upright. Stay off the harness. You don't need it.

Then tweak the 42" to something that seems better balanced for you. Easy stance. Equal force between back and front feet.

Once it feels balanced and you can keep things under reasonable control and maintain reasonable flight, note the position of your feet.

Re-install the front footstraps to the noted front foot position.

Foil off into the sunset.

You may just want to forget the back straps altogether. Many do.

Eventually, only eventually, will you get back onto the harness. Robby Naish foils without a harness.

kiter49
84 posts
26 Jul 2020 5:16PM
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I swithched us cup for Euro pin and this was the best thing I ever made , now I can take the mast off easy offshore then adjust the mast base and put back the mast no problem at all . Same thing at the beach , Euro pin is the way to go for windfoil boards .

LeeD
3939 posts
26 Jul 2020 9:47PM
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If you sit on your board, US double pin is easy to remove and reinstall.
Even you can bend the u or tendon joint 90 degrees and it's not rocket science to line up the pins.

PatK
303 posts
29 Jul 2020 6:28PM
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Select to expand quote
boardsurfr said..
Check out the new mast base from Chinook that has a tendon as well as a mechanical part. It's made specifically for foiling and makes connecting the rig a lot easier. chinooksailing.com/collections/bases/products/1-bolt-pro-flex-mast-base-us-base-cup



Yesterday got three of these flex mast bases from Chinook. They look great. Much easier to connect than the NP Pin. The Chinook pin is more cone shape. I think the tendon will extend longer because the flex absorbs most of the bending.



DarrylG
WA, 495 posts
1 Aug 2020 9:07AM
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Searoamer
NSW, 289 posts
1 Aug 2020 2:13PM
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Select to expand quote
PatK said..

boardsurfr said..
Check out the new mast base from Chinook that has a tendon as well as a mechanical part. It's made specifically for foiling and makes connecting the rig a lot easier. chinooksailing.com/collections/bases/products/1-bolt-pro-flex-mast-base-us-base-cup




Yesterday got three of these flex mast bases from Chinook. They look great. Much easier to connect than the NP Pin. The Chinook pin is more cone shape. I think the tendon will extend longer because the flex absorbs most of the bending.




Are you in Australia? if so, where did you get them? love my Surfbent dogbowl, but it shreds the tendon on standard bases

PatK
303 posts
1 Aug 2020 4:32PM
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No im in switzerland, odered in germany. Moved from cup to pin, cup is hard to get here in europe



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"Foil Board Mast Track Position" started by Poimax05