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Mast Lenght - Racing in Flat water

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Pedro Marcos
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Mast Lenght - Racing in Flat water

Postby Pedro Marcos » Mon Jun 19, 2017 10:18 pm

Shouldnt a short mast 90cm be better for racing in flat water then the longer 110cm masts every races uses? If yes, why they use the 110 then?

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Re: Mast Lenght - Racing in Flat water

Postby Peter_Frank » Mon Jun 19, 2017 10:41 pm

Pedro Marcos wrote:
Mon Jun 19, 2017 10:18 pm
Shouldnt a short mast 90cm be better for racing in flat water then the longer 110cm masts every races uses? If yes, why they use the 110 then?

Hmm, I can not see why it should be better ?

You just ride higher with the 110 so same drag in the water - but you can edge even harder IF there is even the slightest chop, no problem like with the 90.

So if equal in really flat water, most or everyone will choose the one they are used to, which then will perform much better particularly in maneuvers cause they are used to riding the "same".

Control and using the gear you practice and ride all the time, is what matters the most in a race - so you know your foil inside out :naughty:

You are right though, one could use a tad shorter mast in really flat water yes, but as there are no advantages really, nor any disadvantages, the one that can cover all conditions is used.

8) PF

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Re: Mast Lenght - Racing in Flat water

Postby cglazier » Mon Jun 19, 2017 10:45 pm

When racing on the upwind leg a racer wants to lean back as far as possible for the best upwind performance. A longer mast allows the racer to lean back farther.

That is also the reason race boards are very narrow and have beveled sides, so they don't touch the water on the upwind leg when leaning back.

:wink: CG
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Re: Mast Lenght - Racing in Flat water

Postby Mossy 757 » Mon Jun 19, 2017 10:55 pm

The lift vector of the foil pushes the rider upwind the further over they're leaned, so like has been said already, you want more strut not less so that you can have the foil pushing you "upwind" in addition to forward.

Also, sailing with power is all about a righting moment. Having a longer lever (the strut) gives you a longer moment arm so you're able to pull backwards on the kite harder and use more of your weight to hold down power. In an ideal world where struts are made with weightless, drag-free magic-carbon and have perfect stiffness, you'd want a really long strut so you could hike way the hell out and pull against the kite with a longer torque arm.

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Re: Mast Lenght - Racing in Flat water

Postby Pedro Marcos » Tue Jun 20, 2017 12:16 am

Mossy 757 wrote:
Mon Jun 19, 2017 10:55 pm
The lift vector of the foil pushes the rider upwind the further over they're leaned, so like has been said already, you want more strut not less so that you can have the foil pushing you "upwind" in addition to forward.

Also, sailing with power is all about a righting moment. Having a longer lever (the strut) gives you a longer moment arm so you're able to pull backwards on the kite harder and use more of your weight to hold down power. In an ideal world where struts are made with weightless, drag-free magic-carbon and have perfect stiffness, you'd want a really long strut so you could hike way the hell out and pull against the kite with a longer torque arm.
Thats what i was going to say next, then why 110 and not 120 ? Also, having less mast on the water in light winds (less drag) doesnt allow you to go faster? Or its this benefit less, then the upwind angle gained by having a bigger one?

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Re: Mast Lenght - Racing in Flat water

Postby Bletti » Tue Jun 20, 2017 1:33 am

110 already looks huge when at the beach so 120 would look a little ridiculous, in my opinion. The downside of a 120cm would be the loss in stiffness, but who know's maybe in a couple years all the foils on the race course will look like this... :lol:


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Re: Mast Lenght - Racing in Flat water

Postby cglazier » Tue Jun 20, 2017 2:50 am

Longer masts have been tried. To maintain stiffness they must be thicker and heavier. They are also less maneuverable. There are always trade offs.

Racing is where things like this get tried and the knowledge learned benefits the whole sport. I believe most racers are using 100 or 110 cm masts currently.

:wink: CG

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Re: Mast Lenght - Racing in Flat water

Postby Mossy 757 » Tue Jun 20, 2017 1:43 pm

Yeah, stiffness of carbon like this decreases exponentially as length increases, so making your mast as short as possible (given all the other goals) is a good thing for stiffness. My example was the theoretically "perfect/inflexible" carbon that makes a feather-light mast that never bends or breaks.

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Re: Mast Lenght - Racing in Flat water

Postby Peter_Frank » Tue Jun 20, 2017 3:08 pm

Mossy 757 wrote:
Tue Jun 20, 2017 1:43 pm
Yeah, stiffness of carbon like this decreases exponentially as length increases, so making your mast as short as possible (given all the other goals) is a good thing for stiffness. My example was the theoretically "perfect/inflexible" carbon that makes a feather-light mast that never bends or breaks.

Exactly - a practical way many use is the thick "plate box" at the board where a normal 100 cm mast (that can be sold to non racers like me) is mounted, thus you dont get any more flex than a 100 cm mast, eventhough they are 112 cm or something total, and the box is above the water so drag no problem :thumb:

8) PF

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Re: Mast Lenght - Racing in Flat water

Postby bacon2109 » Tue Jun 20, 2017 6:11 pm

nice way to stiffer a mast; @47:30 ----the ketos rider---
https://www.youtube.com/watch?v=oQBY78ad_wA


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