Tall rider (6'5"/195cm), 93kg on Foil Drive Max, 3 blade prop, HP battery, HP motor. 5'3" x 22" Ginxu2 62L (for now). Largest foil: Atlas 960, 170 tail. Step down to Nomad 830, 155 tail.

I can flat water start the 960 relatively easy enough but the 830 is very marginal and really eats battery trying to flat water start.

I find Atlas 960 to be quite efficient and easy to ride while only SUP foiling in surf or light air winging/parawinging (no FD). On the FD however, the different positioning (slammed far forward in tracks to mitigate some battery weight) and general weight of the unit creates a more vague, "washy" feel while riding as opposed to the sharper, more direct feel I'm used to. I don't want to have to ride a larger foil in the surf as the Atlas already is pretty spanny (1020mm). Do others feel this ride characteristic with their foils on the FD vs non-assist riding? I do sort of get used to this difference in ride feel, but the ride character is very different on the FD. I'd love to be riding the 830 more but find it very difficult to FD on without killing battery quickly in the local spot with the current and chop interfering with good take offs. Are others feeling like they can get a very similar feel from their foils when switching back and forth from FD to non-assisted riding? Or is this washy feel just the physics of adding a bunch of weight to the rig and then adapting? Are people shimming tails differently or even using larger stabs for a given foil size on FD?

I have a longer, narrower KT trench board on order to get more efficiency and bring the unit closer to my feet, so hoping this gives a sharper feel. I don't have the benefit of trying other peoples' rigs for comparison for the most part, so my experience is pretty limited with FD. Thanks!

First up what mast and shims you running on the KT gear . Shimming changes everything on the KT super important that the front wing and mast shim values are calculated correctly. Every time you change your mast or front wing so does your shims. For reference I'm 86 kg and use the Nomad 700 for surf and Atlas 790 for DW ( both 155) on the FD flat water both easily and get 50min+ run times. I run a -1.5 or -1.0 on my No Limitz mast I'm riding a DC 4-10 x 18-1/2 x 34 litres Super Trench. The New KT trench board will be insane and will start heaps better than you Ginxu that alone will solve most of you issuses. The Ginxu is not a good starting board for the FD but Super K's are insanely good on the start.

This is from the KT site:-

1. You have to use a Tail Shim.- Without the use of the recommended tail shim between the back wing and the fuselage, the glide and performance of your KT Foil will be compromised.
- Only use shims provided by KT Foiling.

2. Front Wing Value + Mast Value = Tail Shim Value.- The sum of the Front Wing value (printed on product) and Mast value (printed on product) equals the recommended tail shim value (to be applied between fuselage and back wing).

3. Ensure using the correct Negative / Zero / Positive Tail Shim Value.- The simply calculated sum will either be a Negative Value, Positive Value, or will net to Zero.
- Smaller front wings will either result in Negative Shim Values or Zero.
- Larger front wings will either result in Zero or Positive Shim Values.Example 1: Pairing the Atlas 790 (- 1 value) with the 85 cm mast (+ 0.5 value) will add to -0.5, use - 0.5 Tail Shim.Example 2: Pairing the Nomad 980 (0 value) with the 77 cm mast (0 value) will add to 0, use the 0.0 Tail Shim.Example 3: Pairing the Atlas 1130 (+ 1.0 value) with the 70 cm mast (- 0.5 value) will add to + 0.5, use the + 0.5 Tail Shim.

Thanks for the reply, Piros! I'm on the 77cm carbon KT mast and am very familiar with setting up correct shims on the KT gear. I was wondering if people might be shimming little differently on the FD compared to what they'd ride unassisted. There's no way I'd have enough power to get flat water starts on the Nomad 700 on my Ginxu; I'd be plowing and would blow through my boost without getting to lifting speed. For me the 830 takes a ton of one arm paddling (Ginxu is carbon, so signal gets lost if controller goes underwater with throttle hand paddling). Even the 960 needs some paddling once I'm below 50% battery. With wetsuit I'm likely over 97kg. Cold water/air temp must have some effect on battery performance/output as well (west coast Canada in winter, 6-8 Celsius air temp). Really hoping the trench helps as you say as I'm a bit underwhelmed by the Max's power unless I have a wave to get into right away. A Fusion is not an option for me at the moment.

To get more lift on the start increase rear wing size and positive shim it more. As I mentioned above the Ginxu 2 wasn't built with the Foil Drive in mind .Your new board will dramatically help on the starts. I assume you have dialed the FD to MAX power & boost in the app , have you got the HP motor and battery. Slow starts and missing starts is the battery killer once you nail your starts battery run time will increase dramatically. The foils you mention are all really good starters with plenty of initial lift. I'd go back to the flat water and burn a few batteries practicing the starts like this. 1/make sure your finger is off the trigger don't idle around as you only get 6 to 12 secs of high boost pending how you set the app .2/ Lift your feet out of the water and don't use super long leg ropes it's all added drag , short coiled ones are best. 3/ Position yourself forward on the board facing downwind and pull the trigger as the nose lifts rock forward on your elbows placing more pressure on the nose 4/ Let the board accelerate then pull yourself up onto both knees with both your hands still on the deck 5/ Let the board keep accelerating and as it wants to Lift bring your back foot forward first ( yes back foot) then the your front foot and boom you are away . As you get better just speed up the process , don't rush it let the board accelerate through each phase. You know you are starting to get it right when you get thrown off before you get to both feet

The biggest killer in starts is laying too far back on the board and it makes it feel like the FD has no power , the next one is getting to the knees too early it just makes the board bog and drag tearing up the battery. It's practice practice and then more practice and then all of a sudden BOOM you are just popping up. Try that and let me know how you go.

Thanks for taking the time to post that detailed tip. Might be time for a bigger stab on the smaller foil. Feel like I'm doing all the things you describe minus back foot up first, so I'll change technique there. I have all settings turned up to full power, so it's surprising I can't get the 830 consistently lifting without paddling like mad fully forward on the board. Funny, I was telling a friend before the Fusion came out that "I wish Ihe Max had 40% more power on the start", then of course the Fusion launches with 40% more juice, LOL. Anyway, I'll keep practicing!

I don't foil drive but been riding KT for over a year now. There's a massive difference in size between the 960 atlas and 830 Nomad.960 atlas is actually a pretty big foil, I SUP DW it in 12ish knots.
I think with the foil section on the Atlas and Nomad, the additional span adds more and more early lift(like 15cm difference between the 2 foils mentioned ).I've had a go on the 1130 Atlas and that is just ridiculous compared to other 1100ish area wings on the market

Select to expand quote

Spark said..
I don't foil drive but been riding KT for over a year now. There's a massive difference in size between the 960 atlas and 830 Nomad.960 atlas is actually a pretty big foil, I SUP DW it in 12ish knots.
I think with the foil section on the Atlas and Nomad, the additional span adds more and more early lift(like 15cm difference between the 2 foils mentioned ).I've had a go on the 1130 Atlas and that is just ridiculous compared to other 1100ish area wings on the market

Yes, this is the reason I don't feel the need to go bigger than 960 for any of the foil sports even at 93kg. Even the 830 will get up easily for me in lighter air wing foiling. FD is a different story so far, but there's more efficiency to be gained by making a couple of tweaks (longer trench board, Zip pod). We'll see!