Pumping high aspect foils

I am riding RRD foils. They have a lovely mid aspect ratio foil (Blaze) which is my go to most of the time and seems to have excellent range through all speeds. However I recently tried a much higher aspect foil (Spark A/R 9), which is actually designed for Wing racing, but I am struggling to get the pump going. I don’t know if this is a generic thing with high aspect foils, or a foil specific thing.

I find that it is so sensitive to pitch in the pump. So typically I come off the wave with speed and high on the mast. It has excellent glide and I can keep it going for 2 to 3 pumps with a light tapping technique, but when the mast starts to get lower and I need to do 1 larger pump to get high again, the foil always stalls.

So question 1… Is this fairly normal for high aspect foils? Any technique to get back high on the mast without increasing the pitch too much and stalling?
Question 2… Any set up tips with the tail (or mast position) to help with the issue. Normally I ride a small mid aspect tail, with a shim and this feels really good on my normal foil. However for the higher aspect foil, I don’t know if it would be better matched to a larger higher aspect tail with less shim.

Any advice most welcome.

Fairly normal. If you let a high aspect foil point up to high it will stall out on you. You have to let your speed do the work. So go faster I guess? Pull out earlier when you have more speed and maintain that speed.

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Resist the urge to do this and rather try nurse it up with smoother taps and light footwork. Key is not increasing the angle of attack of the foil much above flat, as that will cause it to drop out, also don’t do any harsh movements. You can sometimes recover when you lose altitude and speed but it’s tricky.

(in theory, I’ve largely kept to ~8AR unless conditions are very clean and glassy for this reason)

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I feel your pain here - spent a year almost exclusively on mid aspect SPG Game Changers and when the Missile 120 arrived I felt like I couldn’t pump any more first few times out. It was amazing on the wave but I’d go to kick off and pump back out and stall out straight away unless I had loads of speed.

What these guys said is spot on :point_up_2:t2: the HAs don’t like being manhandled so just keep pumps delicate but faster cadence. Don’t try and change direction too abruptly either.

A longer fuse helped me a lot. I guess this is because the longer lever length forces you to pump shallower. I just experimented with lots of tails until I found one that worked best for me too.

But I think mostly it’s just resetting that muscle memory. The more I ride it the easier it’s getting to pump.

Don’t think I’ll go back to MA except for turbulent conditions or a lot of whitewash as I love the speed and the carve the HA gives too much.

My 2p worth!

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Don’t know if it’s relevant or helpful, as I can’t even prone foil, but I dialed my HA pumping skills on flat water, in light wind conditions with a wing, with 3 different wings from 840cm2 AR 7.6 to 1180 cm2 AR 10.4. And indeed, with the smallest one I find it’s easier to do these deeper pumps, and the two bigger ones require a bit more care and finesse. With the help of the wing it’s real easy to try different techniques, to find out what works better with each foil. Especially if the wind is light, so the wing is just helping a bit to keep going. Here’s a 987 cm2 AR 10.1:

Thanks for all the tips. I will focus on keeping it level and also try the longer fuselage.

Any general rules with the tails? or just trail and error?

I don’t think it’s a high aspect specific thing, more a foil section and it’s intended usage. We have high aspect foils that are designed to have a very high top end and relatively high stall speed, and ones that are designed to have a much lower stall speed at a cost of some of the top end. Both have good glide, but the higher end racier foils don’t like to be pumped hard as can easily stall out. Suspect the foil sections are quite different on the two foils you are comparing…

Thanks for the alternative view point.

I haven’t had much chance to get back out on it since asking this question last week. Waiting for a nice easy glassy day to really test it out.