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Stefan Lloyd View Drop Down
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Post Options Post Options   Quote Stefan Lloyd Quote  Post ReplyReply Direct Link To This Post Topic: New Development Classes
    Posted: 06 Feb 06 at 7:07am

Originally posted by JimC

Originally posted by Chris 249


There's a distinct link between the level of the racing, and the width of the competitive weight range.


'xactly so. At club level you don't really need to worry about the right weight too much.

But at, say, Nationals level, you do.So bringing in the fact that the Laser is an International and Olympic class is completely irrelevant to the point I was making: here is a popular class with a narrow competitive weight range.

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Chris 249 View Drop Down
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Post Options Post Options   Quote Chris 249 Quote  Post ReplyReply Direct Link To This Post Posted: 06 Feb 06 at 9:13am
Surely it IS relevant, because at many Laser nationals the reason you have to worry more about weight is due to the fact that you have to sail against guys like this;

1st - Basically full-time Olympic aspirant (2nd in trials, about 6th in the world's biggest adult's class, full coaching support etc)

2nd - Full-time Olympic aspirant (multiple winner on the Euro Olympic circuit, full coaching support etc)

3rd - Overseas basically full-time Olympic aspirant.

4th - Ditto.

5th - Overseas Olympic aspirant (don't know whether he has a job as well or is a full-time sailor).

6th - Ditto

7th - Ditto

8th - Masters world' champ, got a degree in a sports science, was 88kg and regularly beat Olympic medallists in light winds, said that weight was not a problem.

9th - Overseas Olympic aspirant who doesn't seem to need to work.

10th - Overseas sailor, two-time Olympic representative.

It seems a bit hard to say that a national title fleet which has 26 overseas sailors (including top Brit Mark Howard down in the 'teens) is not more demanding, in this respect, than a fleet like the Solos which has lots of very good amateur sailors.

I sail one class that was very big but got dumped from the Games while I've been in it, and one class that is enormously popular and was put into the Games while I've been in it. The demands in all respects are so much higher in the class with Olympic status that you just can't compare the demands of the Olympic classes to the demands of the non-Olympic classes IMHO.

A classic case is the weight range for the class that got dumped from the Games. If you looked at the top 3 guys at the nats 2 years ago when it was an Olympic class, you'd say the weight range was about 68-71kg - very tight!

If you tooked at the top 3 guys at the nats 2 weeks ago, you'd say the competitive weight range was now about 59 to 74.5 kg - pretty wide. Yet nothing at all has changed with the gear - just the level of competition.

































































































Edited by Chris 249
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Chew my RS View Drop Down
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Post Options Post Options   Quote Chew my RS Quote  Post ReplyReply Direct Link To This Post Posted: 06 Feb 06 at 2:17pm

Getting back on thread...

Based on America's Cup rules, how about:

length + 1.25*(upwind sail area)^0.5 - 9.8*(total displacement)^0.333 <=3.00m

and

kite area =17m2

max beam = 2.0m

This system allows for a wider variation in designs (trading length for sail area etc), but I'm not sure whether that is a good or a bad thing. Probably bad in this instance as it might lead to a greater rate of change of design and correspondingly high cost. The simple rules proposed by Jim are probably better, but this offers an interesting (to me at least!) alternative.

For information the RS400 comes out with a value of 2.91, the Topper Xenon 2.77 (with a crew weight of 150kg) and the 59er 2.97 (based on a heavier crew). All are 2.0m wide, but the 400 and Xenon could trade up to a bigger kite whilst the 59er would need a smaller one. I'm not suggesting that the Xenon could seriously race the 59er over the water, but it does illustrate the point that most of the big manufacturers have produced boats in this area of the market. Wouldn't it be better if they united behind one class rather than creating three smaller ones?

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Isis View Drop Down
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Post Options Post Options   Quote Isis Quote  Post ReplyReply Direct Link To This Post Posted: 06 Feb 06 at 4:56pm
I dont think trading length for sail area has the intended effect in planing dinghies tbh, although its a nice idea.
In displacement mode a longer hull is worthwhile but once you start planing length starts to matter less (except for controlability) and rag starts to matter more.

How much cloth am I allowed on a 6ft hull?
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Post Options Post Options   Quote Chew my RS Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 8:12am

That's one reason I wasn't so keen on it, but there's only so much rag you can hold on a 2m beam without trapezes. Downwind all the boats would have the same sized kite, which is the totally dominant sail.  I don't think a big main is that much use downwind. The RS400 doesn't plane upwind effectively anyway, so the formula is only rating this type of boat in displacement mode (I guess the 59er probably can plane upwind though).

A 6 foot boat with all up weight (inc crew) of 200kg could have 30m2 of sail. Now that I'd like to see!  In practise, holding more than 15m2 would be tricky so there's no point being shorter than about 14 foot, with higher low end speeds likely on a 15-16 footer.

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Post Options Post Options   Quote Strawberry Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 11:30am

Originally posted by Chew my RS

Downwind all the boats would have the same sized kite, which is the totally dominant sail.

That's not true. You spend loads more time going upwind than you going down with the kite up. Therefore upwind speed makes a loads bigger difference.

Originally posted by Isis

How much cloth am I allowed on a 6ft hull?

Originally posted by Chew my RS

A 6 foot boat with all up weight (inc crew) of 200kg could have 30m2 of sail. Now that I'd like to see! 

Sounds like a challenge! (Bit heavy tho)



Edited by Strawberry
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Post Options Post Options   Quote Chew my RS Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 11:45am
Originally posted by Strawberry

[quote=Chew my RS]Downwind all the boats would have the same sized kite, which is the totally dominant sail.

That's not true. You spend loads more time going upwind than you going down with the kite up. Therefore upwind speed makes a loads bigger difference.

I meant going downwind the kite is dominant, therefore whilst going downwind the size of the main and jib is of secondary importance.  Upwind speed is important, but sail area is just one function of upwind speed.  The formula lets you chose the combination of length, weight and sail area that you personally think will provide the best upwind speed in a range of conditions.  Downdwind the formula doesn't really hold - as the boat would potentially be planing, hence the proposed kite area rule (as kite area is the dominant factor downwind, go to start of post, collect £200...).  Obviously a lighter boat would help the downwind speed as well, but at the expense of length or upwind sail area.



Edited by Chew my RS
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Post Options Post Options   Quote Strawberry Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 11:48am

Originally posted by Chew my RS

Downdwind the formula doesn't really hold - as the boat would potentially be planing

May I suggest that if your design doesn't plane upwind (in conditons when your planing down) then your gonna be sloooooooooow.

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Post Options Post Options   Quote Chew my RS Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 11:51am
Originally posted by Strawberry

Originally posted by Chew my RS

Downdwind the formula doesn't really hold - as the boat would potentially be planing

May I suggest that if your design doesn't plane upwind (in conditons when your planing down) then your gonna be sloooooooooow.

No, you can't.

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Post Options Post Options   Quote Strawberry Quote  Post ReplyReply Direct Link To This Post Posted: 07 Feb 06 at 11:56am
Originally posted by Chew my RS

Originally posted by Strawberry

Originally posted by Chew my RS

Downdwind the formula doesn't really hold - as the boat would potentially be planing

May I suggest that if your design doesn't plane upwind (in conditons when your planing down) then your gonna be sloooooooooow.

No, you can't.

Another well thought out and intellectual repsonse from another SMOD sailor.



Edited by Strawberry
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