Jet-14 Speed Guide (2002, Dirk Schwenk and Contributors)

Jet-14 Speed Guide circa 2002
Editor: Dirk Schwenk
Thanks to: Greg Koski, Brent Barbehenn, Marion Zaugg, Charlie Engler, Todd Lochner, Tom Stout, Ted Reshetiloff, Chris MacMurray, Charlie Engler.

This guide is directed toward the loveable peculiarities of Jet-14s, and we hope that it will help you improve your performance. Like all racing boats, Jets are faster if they are smooth, light, well maintained, and are effectively rigged. There are plenty of general guides out there that cover those topics, and it never hurts to study them. The object of this guide is to give jetters the basic tricks and points that have been proven fast through generations of racing Jet-14s. Remember, however, that if you want to get better, your first priority should be to get in the boat and go sailing. Have fun, meet other jetters, do some racing, and try to get a little better every time.

This guide addresses tuning the boat (mast tuning); techniques for weight and sail trim; and puts it all together by looking at a few pictures of the best jetters. If your mast and rig are within the ranges discussed below, and you use the techniques noted, you will make progress. Once you get your boat to set up to the basic tuning numbers, you can experiment and choose settings and techniques for extreme conditions and the peculiarities of your boat. If you want to make consistent improvement, keep detailed notes in a journal, so that you remember what is fast and what is not.

Speed Guide Part I.
Basic Rig Tuning for the Jet-14
1. Mast and Boom Sections:                         DM-1
2. Mast placement:                                       keel stepped.
3. Mast rake:                                                 20 feet, 9 inches (plus or minus 1 inch)
4. Prebend:                                                    less than 1 inch
5. Mast Butt Position:                                   19 1/2 inches (plus or minus 1/2 inch)
6. Spreader Length:                                      17 1/4 inches (plus or minus 1/2 inch)
7. Spreader sweep:                                       Neutral
8. Rig Tension - side stay:                            140 - 180 pounds
9. Distance between jib leads:                     33 inches (plus or minus 3 inches)
10. Distance to jib leads from stem:            80 inches (plus or minus 5 inches)

What does this mean? Read below. When you try to get these numbers you will find that many of them are interrelated – if you change the tension on the rig, you will change the rake measurement and the prebend. Be patient, leave yourself plenty of time, and keep working on it. Once you have achieved a basic setting, recheck the mast rake before each regatta to be sure that all is well.

Mast and Boom Sections
There are a number of class legal sections (see the class rules), and most nationally competitive boats have Dwyer DM-1 spars. There are fast boats with wood or DM-2s sections, but it has been a long time since anyone won the nationals with a different section. If you do most of your sailing in small fleets and flat water, you can probably compete with a bigger section, but if your goal is to be in the top five at the Nationals, think about getting the DM-1.

Mast step placement
Masts can be either deck-stepped or keel-stepped. Most jets at the top of the fleet are keel stepped, but many club racers are stepped to the deck. There is an article on the website by Marion Zaugg that addresses tuning for deck-stepped masts. Many of the top sailors in the class prefer the keel-stepped because mast bend can be induced or prevented at the deck. This allows for greater control of the shape of the sail.

Rake
Mast rake is a measure of how far forward or aft the tip of the mast is relative to the rest of the boat. Mast rake is measured by attaching a tape measure to the main halyard, raising the tape to the black band, and finding the distance to the top of the middle of the transom. There are some differences between the heights of the transom of various boats, but none that appears to matter significantly. The primary range on this measurement is 20'-8 ½ (698, Brent Barbehenn) to 20'-9 3/4 (1135, Greg Koski). Start at 20'-9, then rake the mast further aft (toward 20-8 ½) if you have too much lee helm or are slow upwind. Rake the mast further forward if you have too much weather helm or are slow downwind. Minor adjustments in rake (1/4 of an inch) seem to have an impact on the water. The goal is to have a nicely balanced boat that is equally fast upwind or down.

Prebend
Prebend is the distance that the mast bows with normal tension on the rig, but with no mainsail up. It is easiest to read by sighting up the luff track on the main. There should be a slight curve, but not too much. Competitive boats have 1/4" (398 Schwenk) to 3/4" (Barbehenn) of prebend half way up the mast. Prebend is related to rig tension, and generally speaking those that set up with more tension, will have more prebend. It is definitely affected by how much bend is restricted or induced at the deck, and if your other numbers are correct, you can adjust the prebend with mast blocks, line or a deck-level mast ram. If you have a deeper cut (ie 1997 UK), you may wish to sail with more prebend, with a flatter sail (2000 Doyle) you may wish to sail with minimum prebend.

Mast Butt Position
The position of the mast butt is measured from the middle of the centerboard pin to the middle of the mast. Historically the sweet spot for the mast butt was between 19 inches and 19 ½ inches. The recent trend has been to move the mast forward (Barbehenn had his at 20 3/4 for the 1999 Nationals), but three of the top four boats at the 2000 Nationals, (including Barbehenn) were at 19 3/8 inches. Butt position is closely related rake and prebend. If your mast rake is right, but your boat has a heavy helm (the boat tries to turn to windward), try moving the butt forward. Some boats (i.e. Hansen and Koski) move their mast butts back in heavy air to induce more prebend.

Spreader Length
This is measured from the face of the mast to the point where the spreader intersects the side stay. Every competitive boat appears to be between 16 3/4 (1066) and 18 inches (1140 and 1129). Koski’s 1135 and Barbehenn’s 698, the two most dominant boats in recent years, are both at 17 1/4 inch.

Spreader Sweep
This is variously described by the distance between the tips of the spreaders, the angle of the spreaders, etc. There is no consistent way to measure this, but virtually all competitive boats have fixed spreaders (this is required on most masts) that do not significantly deflect the sidestays either forward or aft – this is what is meant by “neutral” in the basic setting above. When the rig is tensioned, the stay should run in pretty much a straight line from the top of the hounds to where it attaches to the hull.

Rig Tension - side stay
This is measured with a Loos gauge on the sidestay. Loos gauges are notorious for being different, so the numbers should be taken as rough estimates. Tension (because it involves pulling on the jib halyard) is closely related to rake, so generally boats that preset with less tension can be expected to have a shorter distance to the tip of the mast. Competitive jets set up with 140 (1135) to 180 (698) pounds on the sidestays, although this is an area in which there is less uniformity than in others. Most competitive boats (with noteworthy exceptions including Barbehenn and Dave Hanson) can change their tension (and rake) by adjusting the tension on the jib halyard. Tension is generally increased in heavier air.

Jib leads
This is measured between the points at which the jib sheet turns on each side of the boat. This measurement has been moving steadily inwards in recent years, with competitive boats currently measuring between 31 inches (698) and 36 inches (1135). The distance aft of the bow of the boat is generally between 80 and 90 inches, but this number is greatly changed by the cut of the jib and the height of the lead above the floor. A good rule of thumb is to be sure that the telltales on the top and bottom of the jib break at the same time in medium conditions.

jet 14 basic rig tuning

For those of you that wisely don’t trust anyone else’s interpretation of the data – here are the raw numbers from the 2000 Nationals.

2000 Nationals Top Finishers – Tuning Settings

HULL
Place 1 2 3 4 6 7 8 9
Name Barbehenn Koski Zaugg(1999) Schwenk Bruns Hansen, D Simonds Parramore
Hull # 698 1135 1132 398 1126 1066 1137 1140
Material Glass Glass Glass Wood Glass Glass Glass Glass
Make Mobjack

Mueller

Mueller S & S McKee Hybrid Mueller Mueller
Age 35 2 2 43 10 28 2 2

 

MAST
Hull # 698 1135 1132 398 1126 1066 1137 1140
Material Al'mn Al'mn Al'mn Al'mn Al'mn Al'mn Al'mn Al'mn
Type DM-1 DM-1 DM-1 DM-1 DM-1 DM-1 DM-1 DM-1
Step Keel Keel Keel Keel Keel Keel Keel Keel
Rake 20'8 1/2" 20'9 3/4" 20'8 3/4" 20'8 3/4" 20'8" 20'9 1/2" 20'9 1/2" 20'9 3/4"
Prebend 3/4" 1/2" 1/2" 1/4" 1/2" 3/4" 1/2" 1/2"
Butt Position 19 3/8" 19 3/8" 19" 19 3/8" 19 1/2" 20" 19 3/8" 19 5/8"
Spreader Length 17 1/4" 17 1/4" 17 1/4" 17 3/4" 17 3/8" 16 3/4" 17 1/4" 18"
Rig Tension 180 lbs 130 lbs ---- 70 lbs 100 lbs 150 lbs 130 lbs 140 lbs

 

Speed Guide Part II.
Trim, Technique and other Speed Tips for the Jet-14
Centerboard trim: vertical, tight in the trunk
Rudder shape: leading edge a parabola
Hull trim, fore and aft: bow knuckle 1-2 inches in water
Hull trim, heel: flat to slight heel – helm near neutral
Leech tension: Ease vang and mainsheet in light air
Crew weight: Combined 270 – 330 pounds
Practice: It doesn’t hurt
The helm: Near neutral
Crew communications: Yelling and fighting are slow

Centerboard trim
Recently there has been a strong trend to add a tang to the upper edge of jet centerboards so that the board can be lowered all the way to vertical under the boat. This appears to be faster. There is also very good evidence that it is fast to shim the board to keep it from rattling around in the centerboard trunk. There are significant restrictions in the rules about the size and placement of such shims, so consult the rules or the measurer before putting any in place.

Rudder shape
The rules allow the leading edge of the rudder to be shaved down almost to a point. This is probably slow, and almost all competitive boats have the leading edge of the rudder built up to a fair parabola.

Body Position
Body position is dictated by fore and aft trim on the hull and the need to induce or prevent heel. It’s a good idea to have the weight in the boat as close together fore and aft as possible to prevent pitching. In most conditions, the bow knuckle should be in the water by 1-2 inches, and the transom should be just skimming the water. Other rules of thumb: In light air, move as far forward as possible, typically with the skipper to windward with his or her hip against the windward shroud. In breeze and downwind, move back to keep the bow from plowing – and if waves are breaking over the bow, no matter what the wind, move back.

Leech tension
In jets, the proper settings on the rig will require the boom to be carried higher than horizontal in most conditions, particularly light air. If the boom is pulled down to horizontal, the leach of the main (the aft most edge, where the battens are), is pulled too tight. This causes the breeze to separate from the backside of the sail, and results in a stalled sail. Stalling in sailboats is not as bad as stalling in airplanes, but its certainly not fast. To prevent this, in light conditions, always ease the vang and only pull on enough mainsheet tension to pull the boom in to the corner of the transom, without creating any significant downward force. Once the breeze pipes up, start putting on mainsheet to keep the leech up, and increase vang to help control the boat.

Crew weight
Most good crews sail with a combined weight is between 270 and 330 pounds. At the 2000 Nationals, however, crews in the top four ranged between about 250 and about 350 in combined crew weight.

Practice
It is very difficult to get better at the skills of racing (like tacks, spinnaker sets and douses, gybes, starts, etc.) while a race is actually going on. There is too much else to think about. If you want to get better, spend some quality time off the racecourse mastering these skills. In fact, if you want good crew, this is the only way to get it – practice together, learn the skills, talk about who should do what, and get prepared to be fast. Once you have achieved mastery, you will find that racing is much easier and much more fun, and you can spend more time on tactics and sail trim. When you learn a maneuver, be sure to write down exactly how it is done in your journal. This will give you something to review in the spring so that you can shake off the rust faster.

The Helm
As a skipper, everything from mast tuning to weight placement to centerboard height ultimately comes down to a single question: how does the helm feel? Mr. Sindle’s article from the fifties talks about this, and the sentiment is echoed through time in the articles by such greats as Jamie Brickel, Dave Hansen, and Rhett Simonds. In the 60’s Max Culpepper summed it up perfectly – “the helm is sacred.” If the boat is properly tuned and properly trimmed with respect to weight and sails, the helm should be nearly neutral, with perhaps just a hint of windward helm. This is true upwind or down, reaching or running. This is especially important in Jets, because the rudder, by modern standards, is very wide. If the rudder is pulling in the skipper’s hand, the rudder is dragging behind the boat.

Crew communications
Yelling and fighting are slow. Smooth, quiet communications are fast. If you find yourself focused on a battle with your crew about who screwed up a gybe, you have lost touch with what is important. The real issues include: 1) you did not devote enough time to practice so that you and your crew mastered gybes; 2) you are now distracted from going fast by arguing. Get the boat and your head back in the race. Instead of arguing, at the end of the race, pull out your notebook and write down the ways that you could improve your gybes or avoid the situation that caused the problem. Before the next regatta, review your notes, throw up the kite and practice, practice, practice.

Speed Guide Part III.
On the water

These two pictures are of Brent Barbehenn and Maria Bianchini, sailing upwind at the Parramore, June 2002. Brent has demonstrated remarkable boatspeed and consistent excellence for decades. His crew on this day, Maria Bianchini, had only sailed with him on one other occasion. At the time of the pictures there was about 4 knots of breeze and significant pleasureboat chop. 698 won all of the races in the series by a large margin, despite the fact that the following day featured 14 knots and big waves. Jetters who wish to improve can learn much from studying the unflappable Barbehenn.


It is usually possible to tell a good sailor just by the way that their boat looks on the water. Not by their equipment, not by the age of their sails, but by the other stuff. In these pictures, Brent has four-year-old sails, a 37 year old boat, a relatively inexperienced crew with whom he has sailed just once before, and he still looks and is overwhelmingly fast.

image004

image006

 

Weight trim
These pictures show the niceties of weight trim in a jet in light air. Both crew are maximum forward, with the skipper’s forward hip nearly at the sidestay. Maria is sufficiently to leeward that Brent can comfortably balance on the windward rail. Sitting to windward allows him to feel the tiller and see the mainsail. The transom is just kissing the water – indicating that the bow knuckle is just submerged. Maria’s legs are back so that she is not pulling the jib sheet down and choking the jib leach, but the rest of her weight is forward. Going upwind, maintaining this balance is the crew’s most important job.

Skipper technique
Brent has his butt on the rail (not over it) and his feet on the cockpit sole. This allows him to respond to puffs and waves without having to shift his body at all, except to lean forward, aft, in or out. He is holding the tiller extension and mainsheet right in front of his chest, so that he can use his tiller hand to help with the sheet instead of cleating it. Having the tiller in front of him allows him to use just his fingertips for control, and to monitor how much pressure is on the rudder. Brent’s tiller is nearly dead-centerline, indicating that he is sailing with little or no windward helm.

By contrast, you will sometimes see boats lower in the fleet that have the mainsheet cleated, the tiller extension held like a frying pan behind the skipper’s hip, or with the skipper and crew sitting in the boat on the thwarts. Each of these items seriously reduces the boat’s ability to respond to changes in wind and waves, and significantly increases the likelihood that the boat is being slowed by excessive helm pressure. When in the groove, the boat should be nearly flat, and the helm should be nearly neutral.

Sail Trim
Brent’s mainsail has all of the signs of speed. It has a nice even foil shape with “speed” wrinkles emanating from the mast and running horizontally along the first half of the sail. The upper batten is approximately parallel with the centerline of the boat, and the leech looks nicely twisted for the conditions. The outhaul, despite the light conditions, is taut so as to encourage and maintain attached flow over the back of the lower part of the sail. (Modern testing on sail shape doesn’t support the idea that baggy sails are fast in light air). The boom is dropped from centerline (because the mainsheet is eased, as Brent does not have a traveler), and the vang is off. Its hard to read too much about the jib, but it appears that like the main the upper leech is approximately parallel to the midline and the sail is nicely twisted.

Breeze Up

image007

This picture features Bill Buckles in 1131 at the Konisberg. Bill won the regatta. Boat 604 is Michael Kelly, a solid jetter with experience and a quality boat. He probably finished in the top five. As between the two, one factor immediately jumps out of this picture. Despite the fact that he and his crew are fully hiked, the boat is significantly heeled, and Mike is fighting the tiller to keep the bow down. Buckles, on the other hand, has a perfectly flat boat. He doesn’t even look to be hiking, and his crew may be sitting in on the thwart. The difference? Mike has his main pulled in tight enough to hook the leech to windward: Bill’s leech is open and twisted. If you took a picture of Brent in these conditions, no matter how much breeze there was, you would also find a flat boat, with sails trimmed in order to achieve that result. You would expect, however, that once he was away from the line, the leech of his main would tighten and begin to hook slightly to windward to produce the superior pointing for which he is known. But the boat would remain nearly flat.

Summary

Getting faster is part of the fun of sailing jets. This guide should provide the basic information that will allow you to move toward that goal. In trying to make progress, don’t get too consumed with the minutiae of your boat. Involve your crew in getting better by going out and practicing – this is so much better than spending race day upset about a blown tack or poor douse. Don’t get too involved in gadgetry – time in the boat is far more important than having a tang on your centerboard or a carbon fibre tiller. The best boats often have good gadgets, but the best sailors would still compete in an older boat because their technique is sound and they focus on what’s important. There are many experienced jetters in the fleet, and all of them will help you improve your performance when you ask questions and are willing to listen. If you spend the time to practice and get things right, you will get better, and you will get your own chance to help other, newer jetters. If you try to get a little better every time, you can enjoy your jet for a lifetime. We hope you will.

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