Wow!!!

more

http://www.worrell1000.com/archives2001/may01pics_leg02.html

If I could I would... Have an F16. I like the fact that it can be sailed solo or with crew, that it is small enough and light enough to be moved around, and righted by one person. I'll leave those long ocean races to the 20s! Though I'd like to see a shorter distance race, something like the last "Buzzard" up here, and would like to race in that! I think an F16 could do pretty well...

I'm curious as to what the minimum crew weight is in the F16 class?
The biggest reason we moved from the Hobie 16 class was weight. 45lbs over the minimum crew weight of 285 was way too much to overcome on that boat.

I don't think there is a min crew weight. Like the A-cat, sails are made to fit your weight. I'm at least 40lbs heavier than Paul, with whom I have often competed one-up. We're pretty even in boat speed, just have our rigs tuned differently.

No minimum crew weight, only a miniumum weight for the boat. Number of sails carried is determined by the number of humans on the boat (1-up can max out at main + spi, 2-up can max out at main + jib + spi).

See http://www.formula16.org/ for details.

I have in my notes (from where/what post exactly, I didn't write that down)

"Optimum crew weight = 295 to 308".

I think these number come from the statistic analysis that was done on the Taipan 4.9 boat; read the full article here :

http://www.geocities.com/f16hpclass/F16HP_optimal_crew_weight_analysis.html

About 135 kg to 140 kg (298 lbs - 310 lbs) was found to be in the centre of the competitive range of crewweights over a wide range of conditions. The competitive range is a little larger than the 135 - 140 kg range, which is only a measure of where the balance point is, the centre. With the newer designs (Blade F16) and based on new experiences it appears that the competitive range is larger although its centre is still somewhere in 135 kg to 140 kg's.

Let me reword this. The ideal weight (centre of the competitive range) seems to be around 138 kg (305 lbs); the competitive range itself runs from 120 kg (265 lbs) to 155 kg (345 lbs). When you are at the extremes of this range then you have to order a custom cut mainsail to compensate for disadvantage. Crew in that are relatively close to 138 kg (305 lbs) can just use the standard cut mainsail and be fine.

For many people it is new to have a mainsail cut for their crew weight. One-design classes didn't allow that and this is one reason why OD classes can have rather narrow competitive weight ranges. The formula classes however allow you to adjust your mainsail cut to your crew weight and thus equalize yourself to the benchmark level of 138 kg. This works surprisingly well and formula classes generally show a significantly wider optimal crew weight range. And this all doesn't cost you any more money, just specify your crewweight to the builder when ordering your boat, he will forward this info to the sailmaker and he will adjust the cut slightly for no extra cost.

Don't make the mistake that lighter is always at an advantage or that heavier is always at a disadvantage. By changing the cut of the mainsail you can largely compensate for any disadvantage EVEN IN LIGHT WINDS. This seems contraditionary but it isn't.

So just make sure that you adjust your cut and settings to your crewweight and be competitive.

Don't ever convince yourself that being underweight by a significant amount is an advantage on F16's. A crew of 120 kg will be just as disadvantaged with respect to 138 kg crew then a 155 kg will be. And neither is disadvantaged by really significant amount. The F16's can be made into powerful boats and this keeps the heavier crews in the game while requiring extra skill from really lightweight crews.





You have far more tuning options on the F16 boats and all can be used to bridge the gap pretty effectively. With the additional freedom of sail cut you must be able to make the boat work very well for your 330 lbs (149 kg). Especially if you sail a more modern F16 design. I sail my Taipan F16 at that crewweight and I'm doing well; notice that the Taipan is more sensitive to crewweigt then the newer F16's like Blade and Stealth. I actually raced the Stealth in a series of 11 races together with another guys. We were combined 168 kg (370 lbs) and sailing in 6 to 11 knots. In a competitive 40 boat f18 fleet we consistently finished betwee 21th and 13th spot. We never raced together before this series. I call that a surprising good result, considering the conditions and the crew weight.


Another example. For a while I had the wrong prebend in my mast. Even at 20 knots double trapezing was tentative with 150 kg crewweight (different crew then now). I was lacking in all out speed so I started fiddling about with spreader rake and diamond wire tension. Now I got an rather good setting and I'm double trapping at 10 to 12 knots, pointing higher and going alot faster. So by adjusting the tuning of the mast you can achieve such great differences. Now If I suddenly start sailing at 130 kg I can do the adjustment in reverse. These adjustments is something a OD class around a rather simpel design and using standard sails (one cut fits all), like the H16, can not do.

Wouter

Wouter,
In the first scenario did you decrease the prebend and vice versa for lighter crew?
Just trying to figure if I am thinking about tuning correctly.

Initially I reduced prebend to increase draft in the middle of my sail and have the leech stand up better there as well. This allowed me to stand double trap much sooner when at 150 kg. I placed more power in the rig (that helped me get on the trap much sooner) and that propelled the boat alot faster.

So initially my prebend was TOO curved for the luff round in my mainsail, thus in effect depowering the middle of my mainsail TOO much for a 150 kg crewweight. At 150 kg I could harness alot more grunt then I initially had.

If I were to decrease me crew weight from 150 kg to say 130 kg I would increase the prebend a little again, making the middle of my mainsail a little flatter. With some additional downhaul tension I can then flatten my top and induce some extra flattening of the middle section as well. When the prebend is increased just by the right amount I should end up at close to the proper curve for a 130 kg weight.

But to make things more complex. If I would also derotate my mast a little more when going from 150 kg to 130 kg, reducing mainsail draft that way, then I should reduced my prebend a little less. This because the derotation would make my top become fuller which I will have to downhaul out again by extra downhaul tension. This tension has a side effect on the middle of the sail making it flatten still more. So in order to prevent overdoing it I would need to make it a little too full at zero downhaul tension.

This is the rough guide to it. As you can also play with spreader rake, spreader arm length and diamond wires tension etc. It can get complicited as there are some interdepenceis, but this also means that you have a wide range of adjustments.

I'm still keeping it relatively simple as I would like to find simple adjustments that I can make between races on the beach. Under these circumstances I very much would like to avoid adjusting spreader arm rake and length. So I'm trying to find a good base setting for these and then make do with the thigns that I can easily adjust with the sails hosted and the next racing starting in 10 minutes.

Wouter

Thanks for the explanation-
I am thinking about it from a depowering perspective on 6.0 because I am trying to do more sailing with my wife (120lb) instead of my normal crew (230lb). I have been thinking about increasing pre-bend a little to let the top twist off more. BUT, tightening the downhaul will do the same- if I uderstand it all correctly. But alas, that is not the subject of this thread. I can't wait until Rick's seminar in april

Me niether. I will be there.

Robi-
Sweet... I am hoping that I can get some of this confusion out of my head regarding all this stuff.
I look forward to seeing your boat- I am seriously thinking about the F16.