barak7.7

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Hi all
Need some help please.
Does anybody know how to calculate what is the right bulb weight for the Triumph 800 ?
Length: 800 mm,Beam: 180 mm,Height: 1500 mm,Fully load Weight: 1680g,Sail area: 2500m - but will make her a bigger and smaller sets soon
The original bulb is 600g and with our VERY LIMITED experience with the Century 750 (same boat only 30mm shorter and 55mm shorter keel) a 280g add on made it into a much better boat in stronger winds.
The Triumph 800 has a 55mm longer keel fin then the Century750 ,it is 240mm long .How much the extra keel length is equal in weight ?

Many thanks
Barak

Dorsal

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If I understand what you wrote, the Century750 now has 880g on a keel that's (240-55=)185mm=18.5cm long. That equals 880 X 18.5 = 16280 g-cm of force (torque)
The Triumph800 has a 24.0cm keel, so to get the same force (torque), divide 16280 g-cm by 24.0 to get 678.33g.

barak7.7

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Dorsal
Thanks for that.
If that the case it shoud be ok with the original bulb (600g) on the Triumph 800.
The Century 750 sail much better with extra weight but I was not sure if the 280g was not over kill.
Will test both boats side by side this Sunday

barak7.7

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Dorsal
I tested only the Triumph on Sunday in light winds -she is underweight !
Looking at this web site http://www.racingsparrow.co.nz/index.html
-it is the same size boat as the Triumph 800 /Century 750 - the RacingSparrow are using bulbs up to 1300g on keel fin of 206 mm and a shorter mast.
Using the formula from your post : 1300 x 20.6 = 26780 g-cm .
If we reverse it back to the Triumph 800 - divide 26780 g-cm by 24.0 to get 1115.83g. (1447g for the Century 750 with it shorter keel)
If this is correct then the bulb weight need to be double the weight it came with from the factory

tatolazo

Hi guys.

RG 65 class sailboats sail very good in soft and medium winds with a lenght of 65 cms. and a keel of 27-33 cms. long, the bulb normally are between 450 - 5oo grms. and the total weight of the boat around 1 kilo. sail area 2250 square centimeters ( rig 1), with smaller rigs you can sail in stronger winds.

It is known that brazilean team sailboats weight s around 800 grms. ready to sail, and they RULE!!!, so figure it out!!!!

Best regards and keep sailing.

Tato Lazo

barak7.7

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Done a few mods -very happy with boat for now (prototype 1A)
Video from today sailing (& croc):

http://au.youtube.com/watch?v=yT_8i54kU5A


Some of the mods I done to the Triumph 800 (done some of them also to the Century 750):

http://www.freedrive.com/folder/151024,Triumph-800-mods

Today got myself a Marblehead -now will a whole new "headache" but that another story

Guiri

There's a bit of theory on keel length/ballast on http://f1.grp.yahoofs.com/v1/QHBDSL-.../KeelProps.pdf
I wish I could understand it all