Foil Pumping Theory

Hey Guys,

Made a video on pumping technique I’d be really keen to get this communities’ feedback on. I used the analogy of a skateboard pump track to explain the physics of the motion and associated timing. Pretty simple, but not something I’ve heard before.

Probably no larger collection of accomplished foil pumpers out there than on here so curious if anyone finds this a helpful though experiment. Ultimately, hoping it will be an “a-ha” moment for those foilers who are struggling to efficiently generate and maintain speed once off the wave, but I feel like my pumping improved once I had this mental model firmly established:


Well, I suck, but I’ll throw my two cents anyway. First, I was surprised at the end when you said to shim the nose down to get more speed. I just changed from an appletree pro v2 which has a 1° downward angle on the deck, and among other issues I think the higher AOA while pumping was slowing me down and causing more stalls. I used to shim the front of the plate on takuma v1 and preferred it.

And on the subject of speed, my working theory about projecting forward is that it, in part, helps raise the back foot off the board, WHICH, as the weight comes back on, allows the front foot to bring the nose down BEFORE the back foot/full rider weight lands on the board. This makes most your weight land while that weight generates speed, instead of stalling.

I like your theory on projecting forward. When I remember to focus on it during pumping it does seem to make a difference. Didn’t think to mention it during the video as it’s a more subtle point and not an aspect I’ve wrapped my head around what is actually going on with the physics or if its just a placebo. Maybe it’s just that it helps set up the timing of the tilt/pump better like you say or perhaps there is a subtle forward projection that helps accelerate and is “pulled back” / reset in the glide phase.

Heard similar advice on projecting forward when pumping a shortboard on a wave face as well. I think the ultimate pumpers are nordic skiers! Powerful push followed by glide for long durations. They even do a similar arm swing to be able to push harder and get lighter in the glide. I did a bit in the past but not enough to have any grasp of the subtleties, definitely felt like I was projecting forward on the push though. Would be really interested in a more experienced skier’s thoughts.

I probably glossed over the board shim thing too quickly as the previous video focused on it, meant to just say that shimming the nose down can be useful when trying to generate speed if you know you will be in weak conditions and moving slowly relative to the size of your foil (closer to stall speed). I agree once you are able to keep speed relatively high then the board shim wouldn’t be helpful and could even hurt performance as you’ve found.

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Been loving these graphical videos!!