What are your aims with the FD? Doesn’t sound like prone, so upwind-downwind, flatwater pump practice….? At ~100kg, Here are my thoughts with the standard motor and max battery after a couple of years.
The 3 blade prop is absolutely necessary. Ventilation will still be a problem because you are loading up the propeller so much more than a lightweight rider. Taping has to be really really good and an integrated mast is worth considering despite the cost. You really need a second mast anyways. I still haven’t plumped up for a second mast and my FD usage is frankly compromised enough to not make the original purchase worthwile. Maybe its different in Aus, but here if I get to the spot and the wind is too low to wing I am not making the tape stick to anything in the rain and 5 deg temps so its gotta be done before leaving the house.
A long narrow board is really important and the key thing is that it is not a pintail design. Need something with a bit of area to plane on out back as, contrary to any of the wind power sources the foil drive trims the board nose up rather than nose down. Can’t stress this enough, it wasn’t covered in the orginal infomercial material released by FoilDrive and while it is recognized now, I don’t see it given sufficient emphasis for heavier riders.
You really need two batteries, regardless of what you are on. I only get about 35min of upwind-downwind on a max battery and standard motor, on a big high aspect foil, and with an arrangement where I can mostly duck out of the wind on the way back upwind. This still only works if the wind is under 10knots, above that and battery time drops to 25min or less and the whole exercise becomes pointless. At our weight there is no flying up wind in the open ocean like the Josh Ku videe. At this point I only fall once maybe twice a session so its not relaunching that is eating the battery, and the downwind part I am using the motor less than 5% - only when I stuff up or drift into a dead spot. Reality is flying as a big guy requires a fair bit of juice.
Due to the effects of wind and already limited battery life, upwind-downwind for big boys is a big big foil only activity. The foil needs to be efficient, so fairly high AR - beginner and intermediate foils need not apply. If you don’t have one already, budget for one. I bought one, and found out it works okish for dockstarting and I can wing it from 8knots with a 5m wing and my midlength.
On the gear side, I would only really consider foil drive at 100kg plus if:
-You have or are willing to spend the money on a good, foildrive specific board. Wing/parawing sized midlength carries too many compromises to be a great experience.
-You have or are willing to spend the money on a mast dedicated to FD. Doesn’t have to be integrated, but based on my experiences an integrated will make a bigger difference for heavier riders with respect to ventilation
-You have the money to buy the HP motor and at least one HP battery, plus at least a max as battery #2. This way you can actually get some decent time on foil for all the effort of putting the session together. If you happen to live walking distance from your spot and have good flexibility with your schedule you can drop the second battery and just go for the fast charger if you prefer.
On the foiling side, I think the FD use case for a heavier rider really skews to helping with prone and being able to ride a small enough foil to really enjoy ripping the wave without killing yourself trying to link. Downwind is also a good use case, but I’d argue parawing is better bang for the buck there. The upwind-downwind usage is super duper limited compared to how it works for lighter riders, regardless of standard, HP, or eventual Fusion. I think the extra weight makes using FD to learn to pump quite difficult, and you have to master the FD foot shuffle first. In my experience, dockstarting is a much better bang for the buck way to work on pumping specifically. I will say, learning to FD has improved my balance considerably as, like parawinging, you don’t have anything in your hands to help with balance.
So, have a good think about your budget and what you want out of it. The gear can definitely work and be a game changer for a heavier rider, depending on your local conditions and use case. By the time you build out the full system around the FD it does come at a heck of a cost though.
