Tuning and Sail TrimPaul Abdullah

Tuning and Sail Trim

Topics1.Rig Tips 2. Mainsail Trim

3. Headsail Trim 4. Spinnaker Trim

Rig Tuning

Rig Tuning – Important points

All Boats are different, but here’s some common areas to focus on:

► 1. Mast Centering

► 2. Mast Rake

► 3. Butt (Base) Position

► 4. Pre-Bend

► 5. Side-to-side

► 6. Bendiness

Rig Tuning – Centering the Mast

► 1. Measure from point A to B and divide in half to find the center of the boat, position center of mast to that point

► 2. Swing jib halyard from point A to B and make sure they are the same length, this will ensure the hounds are in the center of the boat

Rig Tuning - Rake

►Rake affects the center of effort/center of resistance (HELM!)

►Max rake increases weather helm to balance the boat

Rig Tuning – Mast Butt Position

►Moving the mast aft to its’ correct setting will induce pre-bend.

►Most One-Designs have the mast butt location in the Tuning Guide.

Rig Tuning – Pre Bend

►What is Pre-bend?

The “natural” bend where the mast is tuned

► Important to set pre-bend because sailmakers build sails to a measurable pre-bend setting

Rig Tuning – Pre Bend

Rig Tuning – Side to Side

► To check side bend sight up the back of the mast

► If the lowers are too loose the tip will poke to weather and the middle will sag to leeward

► If the lowers are too tight the tip will fall off to leeward and the middle will poke to weather

► 1. In heavy air poke to weather in the middle of the mast will depower the mainsail by opening up the upper leech

► 2. A straight mast fits the designed shape of the sail for most conditions

► 3. In light air sag to leeward in the middle of the mast will power up the main by firming up the leech

Rig Tuning – Lower Tension

Rig Tuning – Mast Bend

► 1. Draft position moves aft as the mast bends

► 2. Cunningham tension moves the draft forward

Rig Tuning – Mast Bend

Lots of prebend Little prebend

Rig Tuning

So…..What’s Important???

1) Mast – Centered in the boat

2) Mast – Rake set to balance boat

3) Develop a PERSONAL TUNING GUIDE

4) Bend – To match sails (Prebend)

5) Sight up the mast/main track

a) At the dock

b) On the water in 10 knots

Mainsail Trim

Mainsail Trim – Mechanisms

1) GEAR CHANGES = Speed

2) Mainsheet

3) Traveler

4) Controls

-Vang

-Cunningham

-Outhaul

-Backstay

Mainsail Trim

► Easing the mainsheet opens the leech and decrease weather helm, making the boat easier to sail straight – I.E. 1st Gear

►Oversheeting the mainsheet will close the leech, increasing weather helm and making the bow want to point up – I.E. 3rd Gear

Mainsail Trim Eased Look

1st Gear – Top Batten Open

*Accelerate!

Mainsail Trim Overtrimmed Look

3rd Gear – Top Batten Closed

*Point Mode

Mainsail Trim – 3 Gears!

3rd Gear

2nd Gear1st Gear

Mainsail Trim - Traveler

► 1. The traveler changes power in the mainsail by changing the angle to the wind

► 2. The traveler will also affect

pointing ability

► 3. No Traveler? VANG SHEET!!Laser, new vang

Snipe

Thistle

Mainsail Trim - Traveler

Mainsail Trim - Vang

► 1. Vang affects lower mast bend and leech tension

► 2. A tight vang allows you to ease the mainsheet without losing leech tension

►DO YOU HAVE DECK STEPPED MAST –or- KEEL STEPPED MAST

Mainsail Trim - Controls

► Cunningham

Affects the draft position

Mainsail- Over-Bend Wrinkles

Mainsail Trim

TWIST vs. HOOK

Draft Forward – Big Twist Draft Middle – Perfect Trim

Mainsail Trim - Outhaul

► 1. A loose outhaul makes the bottom of the main fuller for more power

► 2. A tight outhaul flattens the bottom of the sail and opens the lower leech

Mainsail Trim

Loose Outhaul

Closes Slot

Slot Management

Mainsail Trim – Using theTelltail

► 1.The mainsail is overtrimmed when the telltale curls to leeward

► 2. Slight overtrim on the main puts the boat into point mode

Mainsail Trim

Use the top telltail as a

Trim Guide only

Flowing

Stalled

Twist vs. Hook

►Twist is used

To INCREASE FLOW

►To gain speed out of a tack

►To accelerate out of tacks (but sacrifices height)

►To “bleed” pressure

►Hook is used

To DECREASE FLOW

►Captures more airIncreases Helm

Increases Point (but slows you down)

Mainsail Trim

So…..What’s Important???

1) Know the boat’s GEARS

2) Communicate with helmsman

3) Set & Mark your controls

a) Vang

b) Cunningham

c) Outhaul

4) Use your reference points

a) Telltails

b) Trim points (corner of boat)

Headsail Trim

Headsail Trim – Lead Placement

► 1. Low aspect headsails sheet at an angle nearly bisecting the leech and foot

► 2. High aspect sails sheet more directly up the leech

► 3. Moving the lead forward will close the leech for power, moving it aft will open the leech to depower

Headsail Trim - Reference

►Mark your Spreaders

►Gives trimmers visual reference

►Gives trimmers/helmsman verbal reference

► Place marks to correlate with the “GEARS” for your particular boat

Trim Guides

Mark your spreaders!!! Establish Communication

Establish Communcation!!!

Driver

Genoa Trimmer

Main Trimmer

Headsail Trim – Luff Sag

►Headstay sag increases depth in the headsail to add power

► Sag controls sail entry, deep for chop, fine for flat water

Headsail Trim – Luff Sag

► Sag can be controlled through backstay and shroud tension

Headsail Trim – Telltail Flow

► Proper trim allows the wind to flow evenly on both sides of the sail, telltales flow aft

►Overtrimming stalls the windflow on the backside of the sail, creating vortices that spin the telltale

Headsail Trim

So…..What’s Important???

1) Know the boat’s GEARS

2) COMMUNICATE with helmsman

a) Where are you trimmed?

3) Set & Mark your controls

a) Backstay

b) Lead Position

c) Halyard tension

4) Use your reference points

a) Spreader Marks

Spinnaker Trim

Spinnaker Trim

► What are the two fool-proof rules-of-thumb in judging pole height?

► ENDS

► CENTER SEAM

Spinnaker Trim

Even Clews

Center Seam in

line with the

mast

Spinnaker Trim – Pole height

Reaching

► 1. Pole too high flattens the luff and moves the draft aft, closing the leech

► 2. Lowering the pole moves the draft forward and opens the leech

►CONTROLS ENTRY/EXIT

Spinnaker Trim

►As a rule, the spinnaker pole should be square to the wind

Downwind Mainsail Trim

► 1. Too little vang allows too much twist and flattens the top of the main, depowering the sail

► 2. Vang on decreases twist and makes the top of the main deeper and more powerful

Downwind Trim – Main Twist

PERFECT! TOO

MUCH

TWIST!

Downwind Trim – Perfect twist

Top Batten

Parallel to boom

Watch TelltailMake sure it is not

Stalled!!!

Twist in Main - Downwind

Vang on

Please!

Spinnaker Trim

So…..What’s Important???

1) Pole Height & Effects

2) Pole Position to the wind

3) Watch your signs

a) Clew height

b) Center Seam

4) Work the curl!

5) Communicate with driver

Spin Trim- Perfect Balance!