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Kevin 24th August 2006 07:17 PM

Formula questions
 
I've been using a 2000 Formula F155 for about 5 years and love it. I'm 175 lbs and recreationally sail lakes in MN. I mainly use the F155 with my 8.0 retro and occaisonally my 9.5. With the 8.0 I often sail on 10-20 mph days and if pinched for time often ride with winds going into mid 20s. I love the board because I can sail way up wind and explore the entire lakes.

It's got a few dings so I'm considering upgrading to a used 2003 formula 147 wood. I know the F147 are wider (100 vs 85) and shorter (232 vs 270).
Will it work as good in 8.0 conditions or will it feel too big (ie wide), especially when the wind picks up to upper teens?

What fin will be optimal for the 147 and 8.0? 58 cm or 70 cm?

Will it go upwind as well or better F155?

Will it be even harder to go downwind?

Does it have similar reaching speeds?

Thanks for your insights.
Kevin

Roger 29th August 2006 05:43 AM

RE: Formula questions
 
Hi Kevin,
Sorry for the long delaay in my reply here. I have been working aboard the ships and traveling to demos pretty much non-stop since you posted your request. I also did not have internet access over the weekend.
As far as the "differences" between your 85 cm wide F-155 and the 2003 F-147, I think you are going to find the F-155 was better with small sails like your 8.0 m2 Retro.
The F-147 will definitely go upwind higher and faster, probably go off the wind faster, but with only your 8.0 m2 Retro, I'm not sure you will have the power you need to take full advantage of the F-147 with a 70 cm fin.
If you drop down in fin size to say 62-65 cm, you will lose a little upwind performance and early planing, but with only an 8.0 m2 rig that may be the best compromise.
If you aren't racing, I wonder if the F-Type or 2004 Free Formula 138 might not be a better board for recreational sailing. These boards would be a definite upgrade from the F-155, but they do much better with smaller sails.
If you had a 9.5 m2 Retro, then the F-147 might be better.
As far as angles and speed, the F-147 or F-Type 148 will be significantly better than your F-155 with the 58 cm fin both upwind and really far off the wind due to the shorter plaing surfaces and greater width.
As to reaching speed, I think your F-155 may have a small advantage, unless you get a 9.5-11.0 m2 rig to go on the wider F-147 or F-Type 138/148.
Going downwind (recreationally) should not be really hard, just scary. ;)
Hope this helps,

Kevin 29th August 2006 09:28 PM

RE: Formula questions
 
Thanks for your insights Roger. I do have a 9.5 but for the days I go out I rarely use it even though I've hauled it with dozens and dozens of times. It seems like there are many 10-20 mph days where I'm planing >95% of the time on my 8.0 and don't need more power to fly around the lake. If the wind starts gusting into the mid 20s or more the 8.0 is still very fun and controllable where the 9.5 gets to be a lot. The 9.5 is also a real pain to transport because it doesn't fit in my top carrier and is harder to fit in van with the whole family so I've ended up not using it much.

Do you think a 58 cm fin is too small for the F147 or will it work fine with the 8.0 and just not offer as much early planing and upwindability?
ie if I have a 70 and 58 cm fin which would be best on 8.0 and F147?

Kevin

Roger 1st September 2006 08:12 AM

RE: Formula questions
 
Hi Kevin,
Sorry for the delay, but the forums have not been working at all (as I'm sure you know).
I'm still concerned with you getting the 100 cm wide F-147 and trying to use it with your 8.0 m2.
It's going to be difficult to get a good balance or to get the "total" performance from the board with such a small sail.
The 70 cm fin is definitely too big for the 8.0 m2 unless you are really in marginal conditions and need the extra fin size to get planing.
The 58 is probably going to be an OK match with the F-147 in 15 knots and up, but a fin in between would be preferable. Something in the 62-64 cm range would probably be ideal.
Hope this helps,

tmsleung 18th October 2006 10:46 PM

RE: Formula questions
 
Hi Roger,

As you might pickup from the other threads that I am new to Formula type board. So, you mention that extra fin size can help planning earlier?? or I just misunderstand what you meant. If so, what is the theory behind this?

Simon

Roger 19th October 2006 07:30 AM

RE: Formula questions
 
Hello tmslueng,
Having a big 70 cm fin and the tail width (on the board) to be able to control the attitude of such a large fin (footstrap offset=leverage to control the fin) allows a sailor to pump the board against the fin (to some degree) and thus "bounce" the board up onto a plane.
It's really a combination of pumping the sail and the fin to get the sailors weight off the board and allow the board to "porpoise" from the combined pumping actions up on top of the water where the waterline length shortens significantly and this reduces the drag.
There is so much going on when a good sailor on a formula boad gets it going in < 9 knots of wind that it&#39;s very difficult to explain the theory and dynamics here.
Suffice to say, when the width of boards went above 75 cm all of a sudden the fin size increased to 65-70 cm.
Even way back in the Formula 155 days (85 cm wide boards) the stock fins were around 65 cm and most of us who sailed them in really marginal conditions went out a bought a 70 cm fin as this could be used to get the board going really early in very marginal conditions.
It was the wide tail width and footstrap offset, combined with a big change in the rockerlines (much shorter and wider planing surfaces at the back of the board extending forward to just under the front footstraps with a pronoumced "rocker transition" right under the front footstraps and a steadily increasing curvature up away from the water forward of the front footstraps.
This was a major "revolution" in board design, and the largest benefit was much earlier planing, with larger fins.
Hope this helps,


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