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View Full Version : Formula Or Slalom in 20 knots ???


Floyd
2nd January 2009, 06:49 PM
Good thread on Open Forum. Thought it might be interesting to pose question that has developed.

Assuming a windseed of 20 knots which kit would have better VMG (upwind)

Formula or Slalom ??

Any thoughts ???

(Assuming equal/profficient sailor ability)

gre-969
3rd January 2009, 12:18 AM
I do both Formula and Slalom, it's impossible with a slalom kit to beat the Formula in sailling up wind,
in down wind after 25k. maybe it's possible they arrive at the mark the same time but even there the ankel is deeper with Formula.
You should not forget that in higher wind speed we use Fins with less rake +4
and stiffer foil wich makes the board really fast with a lot of control.

www.fwa.gr

davide
3rd January 2009, 04:15 AM
Good thread on Open Forum. Thought it might be interesting to pose question that has developed.

Assuming a windseed of 20 knots which kit would have better VMG (upwind)

Formula or Slalom ??

Any thoughts ???

(Assuming equal/profficient sailor ability)

Well .. better for what purpose? Racing? Is it even allowed by the rules to use a slalom in a Formula race? (the other way around is not)

But anyway, 20 real knots is a LOT of wind. I am 72Kg and around 20 knots I am on my Carbon Art 52W, 6.5 to 5.6, very well powered up and happy. In those conditions I occasionally drag race Formulas at Crissy and the CA seems to be faster downwind (broad reach), while upwind the angle is just a complete different story.

Is the CA actually 'faster" even downwind? Usually I am "only' doing 28-34 Knots of speed, but a capable rider can probably push the CA in the low 40s in the same conditions (my top is 38+). Can a Formula go up there? ... don't know, but the skill that it would require is at least an order of magnitude higher!

Ken
3rd January 2009, 09:08 AM
Davide,

At the speeds you are hitting, you are correct that a formula board can't keep up on the same point of sail (broad reach). When GPSspeedsurfing.com kept a list of formula top speeds, very few achieved speeds over 30 knots (I think 34 was the top).

However, formula boards can run much deeper downwind than any slalom board and if on a dead downwind course, formula will get to the mark first. I have raced with most of the Crissy formula sailors at the US Open in Corpus Christi (all are better than me), so I know what they are capable of.

Ask them to pick a dead down wind course and race them some day. You will hit faster speeds, but you wont beat them to the mark.

Floyd
3rd January 2009, 05:01 PM
Ken
Yes I know exactly what VMG means and have done for over 40 years !! My sailing experience is approaching its half century !

The question wasnt VMG down wind it was VMG upwind in 20knots and in resultant water conditions expected ith 20knots. ?

Yes we all know Formula can outpoint Slalom.

In 2O knots slalom boards approach 40 knots.

There`s a reason Defi is always on on slalom kit.On those days there VMG is probably better.?

Ken
4th January 2009, 12:23 AM
Floyd,

Yes, "Formula can outpoint Slalom", but your question related to upwind VMG. And yes, on a upwind leg, Formula will have a better VMG than a slalom board, assuming the leg is directly upwind.

My above comments only related to Davide's comment that his CA was faster downwind than a formula board and I stated that it wasn't so if the mark was dead downwind.

I doubt that a slalom board can achieve 40 knots in a 20 knot wind in open water with the likely chop and swells. If "approach 40 knots" means 35 knots, I might buy it.

Fun discussion regardless.

Per
4th January 2009, 02:22 AM
Define slalom? When talking about formula we all probably think of a 100 cm wide board with 70 cm fin and monster sail on $$$ carbon rig.
When it comes to slalom both an iSonic 144 being 85 cm wide able to carry a 58 cm fin and a 60 cm wide board with a 32 cm fin can get going in 20 knots of wind. Pointing and speed can vary a lot within this spectrum. Some people claim that even the "old" Hypersonics were able to go near formula boards in pointing and downwind sailing, and, if the sea is rough, probably with a higher average speed through the water.
Anyway on round island races in my local area the quickest around a course this year was... a kiter...

;-) Per

Floyd
4th January 2009, 03:36 AM
Being more specific
a) A Formula 162 with corresponding rig/rider/fin
b) An Isonic 144 with same.

Which one first to windward mark in a steady/consistent 20knots?In choppy and then on flat water.

Ken
4th January 2009, 06:27 AM
Floyd,

Of course the formula board. While the iSonic will do well, it won't keep up with the formula. The 70 cm fin and 100 cm wide board makes the difference. For free sailing, the comparison is of little value, only while racing would the comparison of the two be of importance.

Choppy or flat water won't change the results.

If the iSonic was faster on a formula course, the top sailors would be racing them.

Aco
4th January 2009, 03:37 PM
Hi All.
I do both Formula and Slalom, it's impossible with a slalom kit to beat the Formula in sailling up wind,
Floyd,
Of course the formula board. While the iSonic will do well, it won't keep up with the formula. The 70 cm fin and 100 cm wide board makes the difference.
...
Choppy or flat water won't change the results.
I agree 100%.

If the iSonic was faster on a formula course, the top sailors would be racing them.
Excellent point!
I haven't thought about it, but Formula rules probably don't outrule isonics?

If this was the case and if ANY isonic would be faster than Formula in WW/LW races in ANY conditions, then sooner or later someone would come up with it and win a pro race?

Does anybody know of such a case in the recent history of Formula?
If not then I believe this is enough to close the argument.

Is it even allowed by the rules to use a slalom in a Formula race? (the other way around is not)
This is also an excellent point that suggests that in some conditions (low wind, wind shifts etc.) Formula would probably be faster than Slalom on a SLALOM COURSE (if not, why the restriction?).

The other way around it seems not to be the case (at leas according to the rules).

A fellow sailor has told me his experience about this:
he went to a local Slalom race with a Formula kit with 10m sail in cca 15-30 kts gusty conditions. Even in the relatively windy conditions he came out 6th of approx. 15-20 sailors (!). In the end they disqualified him for using a Formula board.

On the other hand I would be very interested to hear experiences with the other way around - has anybody ever tried/seen a Slalom board doing a Formula race?

Ken has already shared his eperience and it was in line with my expectations i.e.
"Slalom gets ass kicked all the way..."

With Best Wishes,
Aco

Floyd
4th January 2009, 06:35 PM
So we are saying in 25 mph wind we need a 1 metre wide board and a 70 cm fin for best performance ???

Formula has without doubt best "overall" performance. No question. But you are saying this is still case in F5 + .

mmmmm ???

If this is case something is amiss somwhere ???

Per
4th January 2009, 09:56 PM
Interesting points. A few years ago a danish pro-sailor went into a formula race on a small slalom board in protest of the race comitee selecting formula for quite high winds (20-30 knots). He beat everybody to the windward mark mostly due to seriousely higher speed and control. Today I guess it won't be possible. I've seen formula sailors in complete control in +25 knots on 10 m2 rigs beating everything up- and downwind. Five years ago I could kick the ass on any formula board on a reach if I had enough power on my 9.4 rig and Carve 145 freeride board. Today I guess I would find that quite hard. A modern formula is a very efficient and optimized racing machine in a very vide range of conditions. Anyway in pure slalom races I guess you won't see the top sailors competing on formula gear (except maybe in very marginal winds). A one knot in difference may be crucial and around the marks a slalom board definitely performs better - a formula still jibes horrible...

;-)

Ken
5th January 2009, 04:45 AM
Aco,

By just glancing at the official Formula rules, here is what I found.

Must be ISAF approved Formula Boards -

Hull - no more than 100.5 cm wide
Boom - no more than 301 cm long
Sail - no larger than 12.5 m
Fin - no longer than 70 cm
Dagger board - not allowed

I guess if Starboard wanted to register an IS 144 or 150 as Formula boads, they could be raced in the class, but that isn't the case at the moment.

However, if *board thought or found that the IS design was faster than their formula board, they would dump their formula design and rename their large IS boards.

Floyd
5th January 2009, 07:28 AM
Thats probably because its rarely 25mph + at races. Not over entire race and certainly not over a series.
In 25 mph+ extra width and depth of fin is simply redundant drag.Thats why Formulas top out at low 30 knots or so in any wind and its why slalom (even large ones) can get upto 40 knots.

SeanAUS120
5th January 2009, 08:21 AM
I've raced an iSonic 125 with 9m against FW boards in a 20 knot upwind race; and (my Dutch friends might be able to correct/contribute to this) but I believe Ben Van Der Steen rocked up at a local Dutch FW event in 2008 and raced against everyone on the bigger Exocet slalom kit.

It taught me a lot about about the comparison. One thing you guys have missed, and if you go sailing on your big slalom kit in a breeze with a GPS you can confirm this is that slalom boards considerably drop their top end speed (TES) when they point. Its very common even for average sailors to achieve 35 knots TES even on bigger slalom kit but this is usually when they are running on a broad angle. A good angle for TES on FW is about 120 degrees, not sure on slalom but probably similar? When you start to go upwind and point higher on slalom kit your speed drops considerably.

Sure, you can still sail faster than a FW board, but I think you'll find the comparison is about this (rough estimate):

Slalom Kit: 65 degrees upwind angle at 18-20 knots speed
FW Kit: 49 degrees upwind angle at 15-16 knots speed.

Its close. But the FW boards will still beat everything upwind. When I raced on my slalom kit I had to put in extra tacks against the FW boards and despite running much faster, the angles were too lousy to compare. Downwind it was a different story, the slalom board isn't too far away in angle suprisingly and it runs extremely fast so a top slalom sailor against an 'average' FW guy would probably beat them downwind. A top FW guy should win both upwind/downwind.

From memory, Ben Van Der Steen was able to get in the top positions on his slalom kit against the Dutch sailors on FW, however I would doubt he could ever win a race against the strong Dutch fleet. The comparison is "close", but FW still takes the cake.

If anyone is still unconvinced of this in a week or two, I might be able to get some GPS tracks of both sets of kit sailed on the same day - then we could have it on paper the real result. Would be interesting.

namreh
5th January 2009, 06:27 PM
From memory, Ben Van Der Steen was able to get in the top positions on his slalom kit against the Dutch sailors on FW, however I would doubt he could ever win a race against the strong Dutch fleet. The comparison is "close", but FW still takes the cake.


It was the combined NK/BK-event on the Grevelingen beginning of may.
Ben vds (exocet WS80 - simmer 9.0) and also Belgians Wolfgang verlaeckt and Pascal somers entered with big slalom gear just for fun.

Ken
5th January 2009, 11:05 PM
I think SeanAus120 pretty much hit the nail on the head. However, I think water state plays a big role in comparisons between formula and slalom especially downwind.

I reflect back to a couple of US Open events a several years ago with winds hitting 30 knots in the shallow Corpus Christi bay. Chop was easily 1 meter plus with the waves very close together. Most of the pro and out of town sailors were on 9 or 10 meter sails (they didn't bring anything smaller), while the locals like me were on anything from 6.5 to 9.0.

I know I am being conservative when I estimate that the pro sailors were achieving close to 30 knots of board speed on the deep downwind runs. I hit 24.1 knots on my F147 with a 6.5 in the 2006 event (I have carried a gps & recorded all the stats on every outing for the last four years). I was getting blown away by the top sailors and I don't see how a slalom board could have maintained equivalent speed running over the backs of the huge chop while getting air and staying stable over almost every wave.

In flatter water, the big slalom boards will be very fast downwind, but I still recall back when formula first started and there was a good mix of course slalom and formula boards at the US Open. The course slalom boards just didn't have a chance even though the course that was being run was the old "M" type course that included upwind, downwind and reaching legs (to the benefit of the course slalom boards).

There are a lot of top sailors that do very impressive things on their boards, but watching guys hanging on to 9 m sails in 30 knots of wind in 1 m chop is truly amazing. If I hadn't been out there with them, I would not have believed it.

SeanAUS120
7th January 2009, 04:32 PM
Too right Ken!

What's even more impressive, is watching top sailors hang on to "11m" sails in +35 knots of wind!

- Antoine Albeau on 10.7m in the last race of the FW Worlds in Melbourne 2005: 35-40 knots with 2.5m bay swell;
- Steve Allen racing all week on 11m at the FW Australian Championships in Brisbane, 2008: 30-35 knots with 2.5-3m close together bay chop;
... just a few I can think of.

The top end wind speed ability of the ultra-top sailors on FW kit is actually bordering on insanity. Because the tail-widths of the FW boards have increased so much in the past few years the amount of leverage we have against the fin makes it easier to sail a FW board in high wind than it ever would be to sail large slalom kit.

gre-969
7th January 2009, 10:23 PM
And the new sails with their wide leeche are much easier to handle than 2-3 years older ones in strong winds, plus the wider boards,
Formula became much easier to sail in rough conditions.