Choosing the right length windfoil mast

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Choosing the right length windfoil mast

Fromt the North Beach blog

https://www.nbwindsurfing.com/blog?p=dont-be-a-drag-another-thing-to-consider-when-choosing-the-right-mast-size

"That long mast of yours could be a total drag."

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Langdon
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Re: Choosing the right length windfoil mast

For me, sailing in our chop filled Lanier I will take drag over breaching / ventalating any day. Plus the extra height helps with the jibes, especially the tight fun ones.
Also good for me to have the height for running downwind on swell

I have no complaints about the W103.
The taller masts might require bearing off a few more degrees to get up on the foil but y'all know that I will be upwind in just a minute

The extra height gives me more confidence. It allows me to drag race with Barrett or Ed when they are on a slapper.
Yes, they can still beat me but they have to work for it now and my 4.7/5.7m Lifts are not exactly race sails.

Soooo, Not too draggy

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Re: Choosing the right length windfoil mast

I'm a little skeptical that the mast length produces that much drag. Wake Thief on youtube has a video which sheds some light on the subject. This chart which shows that the mast is a very small component of the total drag of the system, esp. at low speeds where one is trying to get onto the foil. There is an explanation of how he came up with the graph in the video. Even doubling the mast length, or cutting in half would have almost no effect on the total drag of the system. Since Wake Thief is not including aerodynamic drag (or using a sail or a wing which also create drag) the mast drag is an even smaller fraction of the total.

What happens in a black hole stays in a black hole.

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Langdon
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Re: Choosing the right length windfoil mast
Randy wrote:

I'm a little skeptical that the mast length produces that much drag.

edit, edit

I would generally concur but in riding around with a GPS, I can get an easy extra mph by being high on the mast at around 18-19 mph.

Just looking at a mast, you wouldn't think it takes that much energy to get it through the water but it was very producable.

Looking at his graph, seems we need to spend more time optimizing our fuse.

Thought provoking, though.

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Re: Choosing the right length windfoil mast

Right, but 18-19 mph is 8-9 m/s and not even in the range on the chart so the mast drag (which goes with v squared) may well become more significant. However, the original claim was that the use of a shorter mast would help you get up on the foil more easily in lighter winds (and hence lower board speeds.) I'm pretty well convinced I can get up on the foil at a board speed of in the 3-4 m/s or about 8 mph on the f one board, the Exocet seems to require more speed (which is topic for the other thread).

My mast is only 75 cm so I'd love for NB to be right about this.....

What happens in a black hole stays in a black hole.

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Re: Choosing the right length windfoil mast
Randy wrote:

Right, but 18-19 mph is 8-9 m/s and not even in the range on the chart so the mast drag (which goes with v squared) may well become more significant. However, the original claim was that the use of a shorter mast would help you get up on the foil more easily in lighter winds (and hence lower board speeds.) I'm pretty well convinced I can get up on the foil at a board speed of in the 3-4 m/s or about 8 mph on the f one board, the Exocet seems to require more speed (which is topic for the other thread).

My mast is only 75 cm so I'd love for NB to be right about this.....

Proves my point. At take off speed, a shorter mast would gain you about .25 mph. Lol

Kidding, of course. Leave it to the physicist to deliver the facts. Good

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Re: Choosing the right length windfoil mast

Convenience counts too - any mast much longer than mine (say 100 cm) and I'd be neck deep in water before I'd want to flip the board and foil over and launch. So short masts for a short guy......

What happens in a black hole stays in a black hole.

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