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 MastThe 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 WingOne 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.
AdvantageNo 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.
ComparisonLooking 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
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Obviously, the Aeon is getting a lot of traction after impressive results in 2023 and a very technical design that will suite some riders.
It is worth nothing that F4 had a few issues with their old builder and changed manufacturer to a new state of the art facility that is required to make these complex foil shapes. Unfortunately, this means they missed delivery for training season ahead of this year's PWA.
Performance and Ride FeelSo how do they feel on the water ... in a word.... slick!
These new foils are so slick AND powerful! A magic combination, you really can ride a smaller foil size than last generation. As mentioned, I managed a 30.1kt run first time out on the tiny 366 front wing and 170 rear wing.
The glide through the water is phenomenal. At slow speeds a few pumps are needed to push the foil up and then the magic happens. I had one memorable run on the 540 in very light winds, heading slightly upwind towards the beach the wind got lighter and lighter, so I pulled myself upright over the board with rig vertical and eecked out as much speed in the dying breeze as I could. Conciously riding high to reduce drag, I was surprised at how light the wind was and I was still flying.
Another day I went out on the 540 up against some young friends riding iQ gear and I was able to pump up on the same gusts as the iQ! The glide through the lulls was also about the same as 900! I took the camera out that day F4 540 vs iQ 900
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Later I got a chance to ride the small 366 again with 5m sail in some gusty winds 10-30 kts cold winter westerly. The 366 did need a bit more speed to get up, a decent planing speed on the FMX91. I rigged the foil with a depower shim that made early flight harder but gave more control in the swell. I started to get more comfortable with the speed but only managed 28kts before my feet froze and I couldn't feel the footstraps. I made a foiling gybe at 20kts so there is enough lift in these tiny wings!
Another speed run in smooth water and a negative point come up... but not a fault. Let me explain. So I was on a speed run and got a lot too high... feeling at 101% I tried to back off but knew that I couldn't take my foot out of the backstrap without upsetting the board!! I couldn't drop the harness either and the obvious idea of sheeting out was not enoughto slow down! This insanely efficient design has such low drag that even without power in the rig I couldn't slow down, so had to hold on and deck the board upwind until I regained control.
ConclusionsThe new skinny foils and masts from F4 are an evolution in design that keeps the gear on the cutting edge. The foils are designed for simplicity with just 3 screws for the fuselage and 2 for the back wing making setup a breeze. This design is also powerful and very low in drag making for a fast ride. Send IT!
F4 GP ReviewFor another take of the F4 see Kasper of WindFoil Nederland's video for some good descriptions
F4 Foils GP windfoil series explained (youtube.com)
And he design blurb from F4.Evolution in foiling design since starting with kite foils in 2013.
GP95 GP 95 Tuttle mast - F4 Foils
GP 95 Tuttle mast
We are thrilled to broaden the GP family with the introduction of the all-new GP 95cm tuttle windsurf performance and race mast. The GP 95 mast showcases a streamlined F4 profile with minimal drag, measuring a mere 11.8 mil in thickness. Despite its slender build, the reduced length and the use of ultra high modulus carbon fiber construction significantly enhances both lateral and torsional stiffness to unparalleled levels.
The F4 GP 95 mast utilizes the inventive connection design between the mast and fuselage, an industry-first co-cured and faired construction for the fuselage and wing, and a hassle-free 5-bolt foil assembly. This design effectively minimizes ventilation, ensuring an exceptionally rigid, swifter, smoother, and more efficient experience.
Key Features:- Unprecedented stiffness and slimness: The GP 95 mast is 12% thinner and has a 10% shorter chord compared to the GP 101 mast.
- Streamlined Profiles and Outlines: The GP 95 mast incorporates a blend of low-drag and anti-ventilation foil sections, coupled with a short chord length for exceptionally low drag.
- The GP 95 features an optimized profile derived from extensive Computational Fluid Dynamics (CFD) and optimization software.
- All-carbon or carbon/titanium construction eliminates concerns about corroding metal fuselages and threaded connections.
- Nature-inspired wing shapes with smooth fairings around the wing, fuselage, mast, and fuselage connections.
- PWA RegisteredIntroducing the cutting-edge mid to high aspect ratio Wahoo wings, inspired by the ocean's fastest predator, redefine foiling abilities. Designed for high-performance wing and windsurf race and freerace enthusiasts. Born from a decade of experience, relentless innovation, and cross-disciplinary efforts, the GP platform revolutionizes wind and windsurfing. The GP Wahoo range boasts extremely low-drag, providing earlier lift-off and increased speed with reduced surface area. This results in enhanced race performance and overall ease of use. With their incredible low-end performance and control, the Wahoo wings facilitate smooth foiling during jibes, tacks and wind holes without compromising top-end speed. The design minimizes ventilation, ensuring a stiff, fast, smooth, and efficient foiling experience. Paired with GP masts, they elevate racing to unprecedented levels, responding faster the harder you push.
Design Highlights:
Nature-inspired wing shapes with smooth fairings for optimal aerodynamics.
Meticulously designed profiles, anhedral and dihedral curvatures, and exceptional stability at high speeds.
Profiles based on advanced CFD and optimization software.
Co-cured and faired fuselage and wing construction.
Lift-off at single-digit wind speeds and an incredibly low stall speed ensure top-notch performance.
Construction Choices:Choose between two construction versions for PWA registered race wings: all ultra-high modulus carbon or the R series featuring hybrid ultra-high modulus carbon with a titanium core. Both options guarantee optimal power transfer, propelling you forward with incredible stiffness, speed, maneuverability, and precision.
Wahoo Series Sizes:
Compatible with all
F4 GPproducts, the Wahoo wings come in sizes 366, 466, 540, 600, 700, and 800 and are PWA registered.
AlternativesMain alternatives are available from a lot of mfr's and riden at pwa level:
Phantom - first to 40 knots. Continue with AL fuselage
Patrik - very popjular for 2024 with a few innovative design ideas including adjustable fuselage length by rotating shims (like old powerbox fins).
Zed - first with carbon fuselage but not co-molded. (Well AFS had it first, integrated with mast).
Was I tempted by these... well sure. But I've always liked F4 ever since I got the first set and the integrated foil and fuselage has always intrigued me as a smart solution. I watch F1 and regularly see them tape over all the panel seams on the cars, that should give an indication of how much small dips and ridges affect aerodynamics. Hydrodynamics are even more sensitive to drag. So reducing screw holes and counts from 10 to 5 and moving all screw heads AWAY from the main lifting surfaces makes a lot of sense.
berowne
> 9 months ago, 9 Oct 2024
