I have a couple of video reviews of the new F4 GP series foils.
The GP masts are incompatible with the of CA models and held me off upgrading earlier. Thankfully I had strong second hand interest and sold the majority at good prices so have no regrets!
I seriously considered jumping on the Aeon bandwagon but decided to stay loyal to F4 because the engineer in me really likes the way the comolded foils are integrated with the fuselage.
This does make packing up an issue as the new kit doesn't pack down like the majority of foils. but the lack of screws and associated drag reduction and ease of setup definitely appeal to me. Luckily I don't fly with my foils!
As an aside, I've been watching the development of SpaceX with great interest and Elon is often quoted as saying the best part is no part. If you can take away a part that ends up being unnecessary the final product would be better than if you optimise an unnecessary part. Less screws. less parts to break.
F4 also spent a lot of time finding a new build partner in China for this year and honestly the quality of the new parts is outstanding. as you will see. The density of the new carbon is astounding. Tap them with a knuckle and they reverberate like metal!
F4 GP Wahoo WindFoil Review
F4 new GP Wahoo and GP 95 mast
F4's foil evolution continues in 2024 with a new carbon mast that is thinner than ever yet just as stiff as the original 97 HM model. My first ride out was with a matching Wahoo foil and I cracked 30kts on the day, desperately overpowered but enjoying the amazing efficiency of the new models. They also offer setup simplicity with just 5 screws for the foil and 2 in the board.
The GP series can be combined with the new slalom racing Wahoo, Cobia course racing foils or the free race Gorge or Crissy. Certainly something for everyone.
Front Wings - Game changing design?
F4 are one of a handful of wind wing foil brands with integrated or "co-molded" foil and fuselage components. Coming up with some industry first engineering achievements, I believe F4 is the only brand to use this construction technique for their Windfoil too.
The design philosophy seams to be about increased rigidity of the foil to fuselage join while at the same time reducing the drag from seam lines and screw heads and holes. By removing the screw threads the fuselage can also be thinner with both the lack of screw holes and reduced cross section giving these foils an obvious drag reduction benefit.
The rigidity can also be seen with some of the new F4 wings such as the 870 "Cobia" Course Racing and Slalom "Wahoo" series with the trailing edge of the foil wrapping around and along the length of the fuselage. This design looks really cool, like an SR71 or BlueFin Tuna.
Ultra Slim Mast
The GP95 mast is an allnew design for 2024. The most noticeable features are that the leading edge protrudes forward of the Tuttle box and the top of the mast is wider than the Tuttle box at xxx mm. The chord width and length then taper down dramatically to the fuselage at just 11.8mm and 10.5cm.
There are some obvious similarities with the new series of PWA slalom mast while the flanged fuselage joint is somewhat similar to Phantom.
The minimum cord is 10.5cm and 11.8mm thickness.. Smaller than a slalom fin! For comparison The Patrik and Phantom are 11.7mm according to their web. 11.3mm for the new Patrik. With similar cord length 10.3cm. Z-Fins claim to have a slimmer slalom mast that compromises stiffness while F4 suggest the new 95 is as stiff as the old 97 it maybe not strong enough for a full course racing mast where they recommend the similar 101 mast new for 2024.
Tail Wing
One aspect I'm still coming to terms with is the tail wing joint. The design is elegantly simple and does allow shimming to change angles with very few screw. However, the adjustment shifts the angle of the whole back section of the fuselage along with the wing, rather than just tilting the back wing. The default angle for Windfoil's is 2.5? and just 2? for windwings. I have tested back wings up to 3.5? which is only any good in really light winds but above 10 knots is a struggle to keep in the water at 85kg.
Apparently F4 have some new shims that can slide in from the side allowing deep water adjustment by just loosening the screws, should that be needed.
I've only got the slalom "M" medium length tail wings in the small 170 size, and now the 210 Course Racing Tail in XL that makes the cobia 120cm long! Truly a Cadillac smooth ride. I'm waiting for the 170L model that should help a lot with ride stability.
The Zed Join for the tail wing has two screws one on each side. This allows the same shim to be inserted one way to increase power and the other to decrease it. Only 0.5 degrees is needed to make a noticeable difference.
Advantage
No Manufacturing process is 100% reliable and under the extreme loads of PWA competition delamination is possible.
Elon Musk is often quoted as saying the best designed part is no part. By Comolding the wing and fuselage, there should be one (or 5) less points of failure!
Now F4 have also had manufacturing issues, especially at their earlier factories. The new process is end to end managed by F4 and the details are gorgeous.
Comparison
Looking at the designs across brands and I've noticed some similarities to some of the wind winging foils like Omen, Phantom, and Code too. Omen foils have similar design but aluminium wrap to create strength. Phantom DRIFT wing foils / downwinders have integrated fuselage too but not on their windsurf windfoil set.
Z-Foils have similar integrated front and rear foil with fixed fuselage for kitefoiling.
Patrik foils have separate range for wing (AIO) and windsurf (AEON).
Select have a full range of foils for Wind and Wing foiling, with the Goliath range using separate fuselage. However, I don't believe they are PWA level competitive.
OMEN
More than complete review, great. Agree totally ! Let me add that I had F4 at the beginning, more then two years ago and was very satisfied with 1000 race wing ( 945 cm2 ) 115 fuse and 230 rear. Then came rumours about almighty Patrik Aeon. As my F4 was couple years in use, I wanted new foil anyway. What a disappointment. I must say that we are foiling most of the time in low winds. Aeon 900 was far from good ! Old F4 did it better. Afterwords I was looking for another foil as I sold old F4. Luckily some particular guy from F4 helped me with the infos and his belief in new Cobia and general over GP seies. I waited for Cobia a month or two. It was hard time as almost every day there was wind, but when I got it . . . . . . . I couldn't believe how right the guy from F4 was. Can't explain how happy I am with Cobia and my Tabou 100cm wide board. I don't know the stall speed, but I have the feeling I could foil along some one who walks along me. Foil behaves well mannered, smooth lift off, predictable reactions.... I did try also Wahoo 700 in a bit stronger wind with my Tabou 89 wide board and the feelings are the same.Berowne, reviews like yours really helped people to recognise benefits of F4, as many are totally blind because of Patrik Aeon's success on PWA lately in Sylt and I really am sorry not to have the best rider at the moment on F4 any more.
Best regards to all from another side of a planet