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IQ Foil help.

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Created by cris21 2 months ago, 10 Oct 2025
cris21
WA, 58 posts
10 Oct 2025 11:08PM
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Hi, I have a couple of questions about the IQ and was hoping I could get some help.

Should the angle at the top of the fuse be exactly the same as the angle at the base? Let say the level in top of the fuse vs on top of the board next to the mast base?

I am on the heavier side at 100kg, there are no other foilers in my area to compare take off speed but I feel like I struggle a bit to get going. I have the -2 255 stabilizer with the +1 shim. The reason I feel like I should be flying sooner is because most time I get on the foils I feel overpowered, it feels much better going upwind but if I sail cross wind is a bit difficult to keep the sail powered up without releasing to avoid breaching the foils, going downwind is fine too.

Does the carbon mast make a big difference? Worth the investment?

I'll try to measure everything again and take some photos this weekend to make it easier. I set the level at 0 on top of the fuse.

Severne hgo 9.0 starboard iq board 900cm front wing 95cm aluminum mast 255 stabilizer 115+ fuse

thank you!




aeroegnr
1731 posts
10 Oct 2025 11:23PM
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I'm a pretty average windfoiler (make somewhere around 1/4-1/2 of my flying jibes, not particularly fast) on IQ or on freeride foil setup and I struggle with the 115+ fuse on a reach. Like you, upwind or downwind is a lot easier on that fuse. 105+ makes it a bit easier, or downsizing the sail with the 115+. A foil glide 7.0 is not as performant (less upwind/downwind angle) but easier when more reachy. I can reach but it's out of the rear strap and not fast. I would like to keep pushing but I usually run out of room before having to turn.

Pumping technique takes some time. I've improved some, and a lot of it is picking the right angle in really light wind, technique to keep the board flatter vs tilting towards me, and timing. Also, since you already have the +1 shim you can move the mast base pretty far back in light winds to help earlier takeoff.

For rake, I do not shim the rake unless I am in higher winds with lots of chop, as the rake primarily helps the nose not dig in the waves. More rake hurts takeoff.

The carbon mast will make some difference at your weight, but I would not dump a ton of money into it vs. just getting a newer foil set entirely (unless you really want to compete with strict IQFoil rules).

Also be careful about those masts. They are very sensitive to heat and I'm on my third because two of them snapped. One while flying and I think maybe hitting something or the mast just breaking while foiling and another breaking while I was pumping the sail. Don't go out too far, I've heard stories of people being very far out on that big 530 and having to take hours to get home when it breaks.

Bellerophon
83 posts
10 Oct 2025 11:55PM
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No, the angle of the fuse should NOT be the same as the base : this explains it more clearly
www.windfoilen.nl/en/mast-rake-explained/

Like the previous poster replied rake helps to avoid digging the nose in the chop, bust you also want a specific amount of rake to take off while pushing the back of the board down through the cut out's

If you feel overpowered consider using the 0 shim or even -0,5. Also, move the mast base more forward (in small increments) to push the nose down in gusts.

Remember, this foil was developed for up/down courses so don't compare it to a slalom set-up, although you can make it more docile with the help of a shorter fuselage.

WillyWind
579 posts
11 Oct 2025 12:12AM
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I weigh 80 kilos and have the same foil but with the 1000 front wing instead. Like others have said, that fuselage is meant to be used for up/down foiling. It's quite hard to go across the wind with it unless you are underpowered (small sail or light wind).
regarding rake, I think I have around 3 degrees. The closer to zero (fuse and board are parallel) the easier should be to take off in light wind but if you sail in rough water the nose of the board might hit the waves (easier to make you crash). The higher the board nose is flying, the less chances you dig the nose into the water. But with a higher degree rake, when the board is on the water and you want to get foiling, the foil will be "pointing down" in the water so it will be harder to take off. That's why you see sailors sinking the tail of their boards when pumping. I hope it makes sense.

cris21
WA, 58 posts
11 Oct 2025 1:43AM
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thanks for the reply, so according to that document and Willy i should try to add less rake to the mast? for early take offs and maybe not use the +1 shim since that only adds more lift as i start to go faster?

I haven't tried the smaller fuse, maybe that one its easier to pump and get going in less wind? Thanks for the clarification about the 115+, It felt super easy to push upwind but i just didnt have that much space and had to sail across the wind.

It was super choppy the last time i went out too, I could barely keep momentum when pumping. But I didnt feel like the nose of the board was digging too hard into the chop.

sorry i meant the foil mast but thanks Ill keep that in mind, I sail in long island NY, wouldnt be fun to break a mast in the middle of january or march lol.

aeroegnr
1731 posts
11 Oct 2025 2:03AM
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Choppy, light wind conditions are really tough to get speed and flying in. One miss timed pump will kill all momentum.

When it gets closer to 15-20kts is when i really want to rake and downsize sails. Rake was pretty much necessary for me to be on that wide board and smaller front wings in that wind. Light chop you can fly over with just mast height but any reflecting chaotic chop in 20kts and you're going to stick the nose and go over the handlebars unless you sheet out and only fly at 15kts.

The 95+ is sailable but it is nowhere near as stable feeling as the 105+ on that setup. It probably works a lot better on the 1100 or whatever size freeride wing. The 95+ and 105+ both stick forward of the mast about the same, but the length of the tail on the 105+ noticeably helps. I like it on 725 and below.

But I hear all the new foils like the aeon are a lot more stable and more performant, just haven't sailed them myself.

cris21
WA, 58 posts
11 Oct 2025 4:13AM
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i was hoping to find a 1000 front wing but wanted to get used to the 900 wing. do you know if the difference going from the aluminum mast to the carbon foil mast feels as strong as going from a regular fin to a carbon fin in slalom for example? i feel like theres a lot of flex on the alu. and when i really push it i can feel it like it snaps back

aeroegnr
1731 posts
11 Oct 2025 4:37AM
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Willywind, who responded to this thread, may be the one you want to ask. I vaguely remembered a thread and found it, looks like he has done that. I'd just hope you would get a used modern of the right stiffness, as they had several different stiffness masts, and you don't want the low stiffness one.

www.seabreeze.com.au/forums/Windsurfing/Foiling/From-Alu-to-Carbon-mast--Is-it-worth-the-price-?page=1

WillyWind
579 posts
11 Oct 2025 8:50AM
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I bought my iQfoil with the alu mast (youth version) after a few months, one of the holes for the barrel nut developed a crack. Under warranty, and paying the difference, I got the carbon mast. I took some crude measurements with weights and a caliper. There was not a lot of difference between the masts in terms of flex but the difference regarding torsion was significant.

In the water, the foil felt much stable. With the alu mast, passing through boat wakes (turbulence) felt almost scary but with the carbon mast it felt WAY more stable. I think I said it here, it was totally worth the investment.

I would not recommend the c300 carbon mast because I have heard it is pretty wobbly. It makes sense because it was the first version. The iQfoil carbon one is the c400. there is also the c600, which it is supposed to be even stiffer but much more expensive.

BTW, I am selling my foil (1000, two 800, 650 wings, 95, 105 and 115 fuses, 255 -1 stab, Carbon mast) and I am willing to ship from Seattle. All that for the price of a new iqfoil carbon mast :)

Mark _australia
WA, 23433 posts
11 Oct 2025 4:39PM
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Do not shim the head in the box if you want it to last (tears rear bolt thru the box with monotonous regularity)

Bellerophon
83 posts
11 Oct 2025 5:19PM
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Select to expand quote
Mark _australia said..
Do not shim the head in the box if you want it to last (tears rear bolt thru the box with monotonous regularity)




Disregard this "advice" : it has been discussed-here and elswhere- ad nauseum .

The origins of this myth date back from the beginning of windfoiling when people where adapting formula boards with tuttle boxes for foiling.
In the mean time the industry adapted the box so as long as your using a dedicated foil board, or a board wich is "foil ready" you won't have problems.

Mark _australia
WA, 23433 posts
11 Oct 2025 7:25PM
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I repair torn thru rear bolt in IQ boxes - professionally. For money
Regularly.
Sorry for my "advice"

aeroegnr
1731 posts
11 Oct 2025 9:21PM
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To Mark's point make sure you use the big metal washer under the rear bolt. Mine came just after they started throwing those in with the kits.






cris21
WA, 58 posts
11 Oct 2025 11:31PM
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planning to go sailing today, im gonna try to see at what speed i get on the foils with the gopro. I am pretty sure my pumping technique needs a lot of work so would be great to get some advice on that too. I dodnt have that specific washer but i always use the biggest "regular" washer i can put in there.

aeroegnr
1731 posts
11 Oct 2025 11:54PM
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Definitely buy one then. They are 8 bucks and will save you a lot of pain

Karbonko
31 posts
13 Oct 2025 1:54AM
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When i was using the IQ foil (just the foil not the whole combo) with 900 wing, the sweet spot was +0.5 degre shim on the back with the 255/-2 back wing. Rake at just under 2 degrees is where the pros have advised me to set it for most conditions. If flat you can go to 1 degree or in very rough waters around 2.2-2.5. Our current best iq foiler has a top speed of 31 knots on the on the reach. I cant even imagine how he does it... but hes a pro so... My max was around 25 and there was almost no control anymore :D. Its not a friendly setup for going fast that's for sure.



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