Had two sessions today: first one on more of a free race set up second on my typical free ride set up. I got way better upwind angles on the freeride set up that I dont think are explained by the slightly lower current (1/2-1 knot) and higher wind (~2-3 knots)

Red Session (free race) ~120L Roberts with outboard straps front only, 6.4m single cam, sabfoil w1110 (1180 cm2, AR = 10), sabfoil s399 with 1 deg shim, fuse 101 cm. 101 cm mast.

Blue Session (free foil) 103L foilstyler with inboard straps, 4.7m wave sail, sabfoil w799 (1100 cm2, AR =5.8), sabfoil s450 no shim, fuse 899, 92cm mast placed quite forward in tracks.

The blue session is much more front foot biased due to mast being forward in tracks and the 450 stab.

Anyways i overlayed the GPS data onto a polar plot (red is freerace and blue is free foil) and it looks like I am getting about 3-4 knots higher VMG on the free foil gear. Seems surprising to me, perhaps a bit more powered on the blue session but still....I would expect the higher aspect foil, larger sail and longer fuse to really help upwind performance, maybe it takes more skill to get raceish kit upwind (ie bearing off to get more speed before pointing like a fin)






Here is the wind sensor data in MPH and the approx tidal current

That is odd. It'd sort of make sense if the tracks were similar, and maybe the free ride one was slightly better, but for the free race foil/board combo tracks to be back and forth only (I presume you were trying to point?) something is amiss, probably with the set up

putting aside differences in wind/current and presuming that you were well powered on the free race set up, how does it feel to ride it? I find to get it upwind I have to keep a fair bit of pressure on the back foot, and use the overburdening power to wind the board up into the wind. You start to feel the need to heel the board to control the pressure when it's happening right.

The roberts is awesome to ride, it gives a very similar feeling/stance to fin windsurfing and its also is unusually comfortable when powering up on a reach. Seemed to be a weird combination backfoot pressure and harness pressure while reaching that seemed to work really well in controlling the lift of the foil. On my freefoil set up reaching is dicey and I doubt I ever get the foil close to its max speed on a reach.

I would say that I was moderately powered on the free race gear, certainly not close to OP. I was very well powered on the freeride gear, but as you know its hard to get OP on foil as you just point higher or lower. Although, I wasnt able to comfortably reach on the freefoil gear, but as mentioned above, I am rarely able to do that.

I was definitely trying to point on the roberts as i intended to use it as a foil raid board. With my current skill level I suspect I would need a lot more stabilizer or a lot more sail to get the freerace set up to point. edit: I was definitely on my back foot, and I think any more may have just resulted in a breach, maybe thats a sign i was underpowered

The roberts is 73 wide, but my foilstyler is only 64cm

Not enough front foot pressure on the first setup.

foilMead said..
Off topic question: what tool are you using to generate the VMG plots? I also have a coros watch, but have not been able to find a good way to make a polar plot like that. Is there a preferred way to export the coros data? (.kml, .gpx, etc...)

Looks like GPS Speedreader but the website looks to be down?
www.seabreeze.com.au/forums/Windsurfing/Gps/GPS-Speedreader?page=1

Grantmac said..
Not enough front foot pressure on the first setup.

Kind of my conclusion too. More I think about it, I like riding front foot pressure because I can get up with less sail, make more of my gybes and allows flagged swell riding without dropping off foil. And I guess it also allows me to point higher and lower. The only negative is that I cant really reach.

Gwarn makes 99% of his gybes, flags on swell rides, but I believe he likes his foil box all the way rear like that roberts. I wonder if he is front foot pressure biased too

I've not seen you on a Robert's so I'm guessing it's new. You've spent years tweaking that freeride foil setup. Give it some time.

I doubt the the Roberts board ( combined with the fuse length etc) is orientated towards upwind downwind vmg, but it should do upwind at least a little better than a fin, and arguably the free ride foil gear.
underdone wind speed wise would make the difference, but I don't think it could be put down to slalom foil vs course race gear.

Yes front foot pressure is alive and well with my style of riding it's much easier to control as it allows you to use your hips to trim your ride so It just happens subconsciously for me.

To the Door that was a fun day as I was up at 3rd ave with a sweet ebb going so nothing but swell ride one after the other.......

I recently got a free race sail just to try something different (Sailworks FR 3.9). Really not what I was expecting. High aspect ratio, shorter boom length. Comparing to my 3.7 wave sail. The FR is a lot harder to launch. Gotta pump like crazy for a long time. No low end power. When I pump, it feels like there's a big hole in the sail. Flying feels really odd with very little back hand pressure and sail trim is going to take some getting used to. I should have up sized a meter. I'll keep at it, but going to need a good consistent wind day (rare here) so I'm not constantly re launching. I've used the regular Flyer which was fine, good power and stability, but the Fee Race version is a completely different animal.

aeroegnr said..
Looks like GPS Speedreader but the website looks to be down?
www.seabreeze.com.au/forums/Windsurfing/Gps/GPS-Speedreader?page=1

GPS Speedreader downloads are now at github.com/prichterich/GPS-Speedreader

Try moving the mast further back... physically the relationship between mast base front foot and front foil are the most important. If you give the foil excess power then you should be able to point higher... rear shim angle and or longer fuselage can help to.

berowne said..
Try moving the mast further back... physically the relationship between mast base front foot and front foil are the most important. If you give the foil excess power then you should be able to point higher... rear shim angle and or longer fuselage can help to.

berowne,
You are saying move the sail back, right? I hate the vernacular that we use, there are two masts on one small craft! Don't get me started on front wing verses hand held wing! Which wing are you on brah?

I don't have polar graph or any data other than lining up against mostly wingers these days but bringing the sail aft has noticable improved my VMG. The other thing it (sail close to foil) changes is yaw balance (ie weather/lee helm) bringing the sail back increases weather helm which improves upwind vmg but makes it harder to reach. I only use reaching for brief moments to get flying or accelerate for a turn or wave. It's funny I do less and less dingy racing so I can go foiling more but still sail windward leewards out wave riding

thedoor,
Nothing beats two boat testing! I wish could line up against ya, I am sure we could learn a ton! ATM I am the only one in my area that windsurf foils. I am sure you can find some one in San Fran! Maybe Gwarn????