Moth on Foils: 35.9 knots(41.29 mph)

[Doug Lord]

Moth on Foils: More Speed-Better Ride

Check out Rohan Veals blog-he and Amac appear to have made a fairly significant improvement in boat speed(5-10%) as well as an improved ride on the Bladerider.
Rohan Veal: Home Page
Address:http://www.rohanveal.com/ Changed:4:25 AM on Wednesday, May 23, 2007

 

[Doug Lord]

Moth on Foils: Formula Board bites the dust vs Rohan in 20+

Some weeks no news-this isn't one of those weeks-check out the great story where Rohan races a Formula board with an 11m sail (approx 50% more SA than a standard Moth sail) in strong wind.
Rohan Veal: Home Page
Address:http://www.rohanveal.com/ Changed:1:38 AM on Wednesday, May 30, 2007
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John Ilett has been awful quiet recently; could there be something brewing in Perth? Some more thunder from downunder? I hope so.....

 

[frosh]

Doug, get it into perspective!

Firstly , However Marty is, I don't know. Is he a national or world champ in FW? Was he on his best gear on the day in question? Maybe Robbie Radis may have beaten Rohan convincingly on the day. And-- the difference was only 15 sec in favour of the Moth.
John Ilett , if he has been awfully quiet lately in Perth, lately is because maybe not much is going on business wise in Perth in his specific area.

 

[frosh]

Doug, get it into perspective!

Firstly , However Marty is, I don't know. Is he a national or world champ in FW? Was he on his best gear on the day in question? Maybe Robbie Radis may have beaten Rohan convincingly on the day. And-- the difference was only 15 sec in favour of the Moth.
John Ilett , if he has been awfully quiet lately in Perth, lately is because maybe not much is going on business wise in Perth in his specific area.

 

[boogie]

i know Marty.
he's a really nice guy, met him in 2003 in Melbourne.
he's a good sailor with dinghy experience too, but he sure is no worlds contender.
when they had the FW worlds in Melbourne in '05 he was not qualified for the event as far as i know.
he did sail the national event before the worlds though and finished 26th out of 37.
http://www.sailmelbourne.com.au/race-results/2005/vicwindsurf/SGrp1.htm

boogie

 

[Doug Lord]

And-- the difference was only 15 sec in favour of the Moth.

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You know-maybe the foiler Moth is just plain fast as hell? ya think?
At an average speed of 16 knots(they were both much faster downwind) and a 15 sec margin we're talking a 400' lead by Rohan or 36 boat lengths.....
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Be sure to check Rohans blog today for a clarification of the "5-10% speed and ride comfort gain" mentioned in a previous post....

 

[boogie]

i'm wrong. it was 2004 in melbourne.
http://www.sailmelbourne.com.au/race-results/2004/windsurfer/SGrp2.htm
i beat marty by three places in that regatta, but if i remember right i was lapped in quite a few of the races by the two top guys....

that's how big the speed differences are in FW.

boogie

 

[frosh]

Boogie, 100% right on. The difference in FW between the top guy and the middle of the fleet guy is often something 1 klm in a 4 klm race. Maybe Doug can get a hold of Rohans boat in 20 knots and take Marty on (sailing a FW) and we can measure the amount that Marty will win that race using a long-line fishing line; typically a couple of miles long!

 

[Doug Lord]

Moth on Foils

boogie, in your experience with what you've read, heard or actually experienced does a well sailed foiler Moth appear to be able to substantially outpoint a well sailed board?

 

[boogie]

i have no idea.
i have never sailed on the same course with a foiler moth.

if you could get hold of a gps track of a foiler moth and send it to me, then i'll be more than happy to analyse it with www.gpsactionreplay.com and let you know.

i have attached an upwind speed analysis we have done a while ago, maybe that answers some of your questions. i don't know who exactly the rider was, but must have been one of the local Sydney FW crew. those are not peak speeds but averaged speed over longer segments between tacks.

boogie

 

[boogie]

this might also be of interest as it is a track from an actual racing day in melbourne at the worlds from a former WC.
it was windward /leeward racing as far as i know.

 

[Doug Lord]

Thanks for that, boogie. Maybe one of the Mothies will have a track they can get to you. I'd really like to see the results.

 

[Phil Stevo]

I have posted this before somewhere.

We race on the same water from the same start as the FW every week. We have moths from 2 to 8 at our nationals and two of the FW were in the top 10at theirs. So the comparison should be reasonable.

In less than 8kts the FW often do not bother sailing it is so slow for them. At 10 kts the boards can plane but the moths are faster upwind and the boards just catch up downwind.

More wind than that and we are about even upwind but the boards are maybe 20% faster downwind. It is unsettling foiling along silently then hearing all the noise of the board aproach and go past.

So I suspect that Marty was not on the pace of a good FW, because despite 4 or 5 x 10% improvement claims, I doubt that Rohan and the BR are anywhere near FW pace downwind. He does not beat the moth fleet by that much in windy conditions.

 

[Doug Lord]

Moth on Foils-Experiments

Phil, have you ever tried a twist grip hiking stick(extension tiller) to operate the mainfoil flap? Or do you know anyone that has and their results?

 

[TaSSie_deVil]

doug,

I know I'm butting in on a question you asked phil... but there are some practicality issues with that idea:

1) the main foil needs to be constantly trimmed to meet wave conditions. You come to a wave, you want the boat to fly over it, and the bow wand or a bow ski is a far quicker and more accurate with adjusting the main flap to meet the wave than the sailor's reactions would be.

2) The mechanics of it - to have a mechanical twist-tiller adjustable main foil you'd need a CV joint to allow the rudder to move as well as a large assortment of bellcranks and rods to drive the thing. The only other option would be to go down the electronic wireless route (which is banned in moth competition... but wouldn't be too bad an option if you weren't racing as a moth or any other class). While it's possible to do it... it fails to be a particularly practical way of regulating the flight level.

The advantage with the wand or a bow ski or even a bow foil is that the boat's height and wave response becomes 'semi-automatic' and responds as a function of both the lift out of the rudder and the regulated lift out of the main foil (so two variable functions) as opposed to just the lift out of the main foil and a constant out of the rudder (a variable and a constant). The ability for the boat to semi-regulate it's height allows the sailor a brief moment of sanity to get their head out of the boat and sail it as opposed to constantly having their heads inside the boat frantically trying to adjust 6 things simultaneously to ensure the boat maintains level flight for a brief moment before the next wave hits and requires the boat to be adjusted again.

For that reason I'm fairly certain no-one has tried to adjust their main foil using the tiller twist as it adds further complication to a boat that just doesn't need it. The only other main foil arrangement that is a little out of the box is ian ward's raking main foil with a bow wand, which has shown to be quick at times and not so quick at others.