Pumping questions

[Bobson]

I'm posting this under the 'Wing' foiling discussion because I think board pumping is more prominent in 'Wing' foiling. I'm looking to increase my low end 'Wind' foiling without going to a bigger sail size. (7m max) I see some 'Wingers' that are foiling in +/- 10 kts which is impressive with 5m Wings and I think it's because of excellent pumping technique (Wing+board). My 10kts sail size is a baggy 7m sail with an 1100cm2 front foil. I understand many 'Wingers' are using bigger front foils which I'm sure helps with early takeoff.

So my questions are:
How much advantage do you think a 1700cm2 front foil has over an 1100cm2 front foil for early takeoff.? meaning 8kts of wind instead of 10kts with same sail size.?
Do you think that shorter fuse helps with pumping.? If yes, what do you think the best fuse length for pumping.?
Do you think that a shorter board helps with pumping.? I see some dock start/wake riding boards that are pretty small.
Does mast length have much effect.?

Other thoughts.?

I appreciate your feedback and look forward to seeing you Foiling on the water. Wing, Wind, Whatever.

[tempy]

One windfoiler to another ....

The bigger front wing will make a big difference. I use my Infinity 76 (1,534) for almost everything now, but when I use the 84 (2,026) there is much more low end grunt.

If you go up to a 1500 plus wing you will immediately have an easier time getting up and staying up.

I have become efficient enough now with the 76 that I can go sub 10 knots with a 4.7 sail. There have been times when I have pumped it up in less wind than I can sustain flight in, and that is all about the hips, baby!

No idea about mast length (although I imagine shorter is better for pumping), or fuselage (because I have one).

[grantmac]

Foil size is definitely significant, bigger foils can be pumped into the air before the board is foiling.

Another factor is rig weight.
I think I was using my 3 batten 6.3m when you were on a 8.5m cammed sail. I'm guessing my rig weighed half what yours did.

Where windfoiling really works on the low end is with much bigger boards and sails. That's why the IQFoil is 200L and a 9.5m.

[redbaron]

Coming from freeride and more surfy side of windsurf/wing foiling vs racing, I would say 1400-1800 mid aspect front wind on a foil would definitely help in way lighter winds. Plus being able to pump and surf wind swell requires less effort on a lower aspect foil.

Board shape helps too. The foil-only freeride/freestyle boards have better bottom shape for easier pumping on take off.

One thing, I'm excited to try this spring is using a free-style sail for foiling. I have noticed a lot of guys going that direction because of the extra lift a freestyle sail has compared to tradition sails that are design to keep you down on the water.

[juandesooka]

Agree with everyone, bigger foil wing makes a huge difference. There is a noticable difference between low aspect and high aspect wing lift in light winds. Low aspect lifts you straight up at slow speeds and has very low stall speed...you're kind of just standing there, pump the sail to get moving forward faster. High aspect takes off more like a plane, where your forward speed gets you take-off, then once the board is unstuck from the water, pumping the sail accelerates you and you're off.

The lift off for both has a little different pumping technique (at least for wing foil), as the former is more getting pulled up, then forward. The latter is more getting pulled forward, then up.

For boards, a high aspect wing wants a longer flatter board, the faster you can get planing, the quicker you get on foil ... so like race set-ups for windsurf / kite foil, more wetted surface, minimal chines, straight tails with no cut-out are now the thing in wingfoils. With lower aspect wings, I think you can get away with smaller boards, as you don't need planing speed to get lift off. Though I am big believer that a bigger board makes light wind massively easier no matter what, if you can stand on the board independent of wind holding you up. One less thing to worry about. Small board are for powered riding.

I think longer fuse is better for getting up light wind. More leverage.

I suspect a shorter mast would have a slight advantage: less drag. But minor enough to not be relevant. Long mast is generally better in winging, gives you more leeway for breaches. The possible disadvantage is in shallow spots and keeping the foil as close to the surface as possible when wave riding....nothing to do with light wind starts though.

[Bobson]

Low aspect lifts you straight up at slow speeds and has very low stall speed...you're kind of just standing there, pump the sail to get moving forward faster. High aspect takes off more like a plane, where your forward speed gets you take-off, then once the board is unstuck from the water, pumping the sail accelerates you and you're off.

Hey Juan, I appreciate this feedback (all the others too) but this one makes sense to me, with the huge front foil IT lifts me up and with the (smaller cm2)high aspect foils I've been using, it's the speed that gets me up.

I'm going to try my light wind with a BIG front foil and how big a difference it makes. I'm thinking that 9 - 10kts is pretty close to the low end though but with a bit more wind I'm guessing I can use much smaller sails which is really my goal. I can pump a 4.5/5.2 all day long, pumping the 7.0 takes significant more energy, although it's a great workout to help reduce my Covid-19/Winter Hibernation belly. WHAT!?!?

Thanks for your feedback Doods!

[juandesooka]

Should have added too: bigger stab also increases lift and helps pump. Though also introduces some drag for speed and not as turn-y high performance.

All of these trade off in the package...some days I might lean towards big foil small wing, or others small foil big wing. I tend to prefer powered riding, so the bigger wing option gets more play.

And on the really light days it's biggest wing (6m) and biggest foil (1800cm2) and biggest stab (17", soon getting a 20") to maximize potential. I figure 10kts is the realistic minimum, though it's kinda just barely doable, you can ride but it's pretty tentative to do anything in the waves.

We are experimenting with the e-foil assists, which are mainly for surf foiling unbreaking waves or downwinders...but some people are using them with wings on those days where you can't quite get unstuck, but once up and riding you have enough apparent wind to foil....we'll see.