North Sails RESOURCES

Harbor 20 Tuning Guide

  • Last Updated: June 5, 2020
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Thank you for choosing North Sails for your Harbor 20. We hope using this tuning guide will help you get the most from your new North Sails. Our goal is to give you a rig set up that is fast in all conditions and easy to adjust. Some relatively minor modifications are necessary to the standard Harbor 20 layout in order to get the most from your boat and sails.

General

Shroud Adjusters

It is important to have the proper shroud set up for effective rig tuning. Notice the picture above, the keeper allows you to make adjustments with the shroud locking mechanism so you can make adjustments to the rig based off the conditions.

The keeper and third hands will also prevent the shrouds from spinning off while sailing. These can be purchased in a variety of different rig shops.

Adjustable Backstay

In order to properly control the shape of the jib and mainsail it is a big help to have a easily adjustable and fairly powerful backstay. Making sure your backstay is running smoothly will allow you to de-power your sail in moderate wind conditions.

Mast Tuning

Before Sailing

First loosen shrouds until they are making 5” circles. From there tension the upper shrouds until they read 20 on the loose gage. From there fill your bucket half full of water and untie your stern from the dock so your boat is head to wind. Attach the bucket to the main halyard and let your boom sit on the cushions in the cockpit. Hang the bucket over the starboard side of the boat, and cleat the main halyard so the bucket handle sits flush with the bottom of the cap shroud. Then, without uncleating the main halyard, take the bucket and hang it over the port side of the boat. If the bucket handle is hitting the same part of the cap shroud on both sides, this means your mast is in the middle of the boat. If the handle is above the mark on the port side that means your mast is to starboard. If it is below the mark then the mast is leaning to port. Adjust the shroud to get the mast in the middle of the boat.

**Note: it is important that the boat is faced into the wind. Likewise it is important that just one person is in the boat during this exercise, and that person sits in the same spot on both the port and starboard side. Do the exercise multiple times before making adjustments.**

After getting the mast in the middle of the boat, tension the lower shrouds to 10 on the loose gage. Sight the mast to make sure it is straight.

Now you should be ready to race! You should also sight the mast on both starboard and port to ensure the mast is symmetric side to side while under sail.

Sail Trim

Light Air (0-8 knots)

MAIN

Outhaul should be tensioned so their is about 3.5” between the boom and the foot of the sail.

Traveler should be centered. Never let your traveler go to leeward in any situations. There are folks in the fleet who actually screw their traveler to the deck so there is zero chance of it moving.

JIB

Tension jib halyard so that there is a hint of wrinkles in the luff.  Be careful not to over tension.  Adjust jib lead dependent on the jib.  If top telltales luff first, move the lead up on the clew board.  If bottom telltales luff first, move the lead down on the clew board.

Backstay should be adjusted so you have about 1.5” of forestay sag at base setting.

Moderate Air

MAIN

Pull on the outhaul until there is 1.5” between the foot and the boom.  Tension mainsheet so top telltale flies 70% of time; top batten will be parallel to the boom.  This helps to generate power.  Tension main halyard/ cunningham to just remove horizontal wrinkles in luff. Use the main sheet to tension the headstay along with shroud adjustments. If you are easing main sheet, you are loosing headstay tension. Pull on backstay to help with headstay tension and to flatten the sails.

JIB

Trim sheet so sail is 2-3” from end of spreader.  Tension backstay to medium setting.  This will straighten headstay and slightly flatten sail Ideally you want zero sag in the headstay.

Heavy Air

MAIN

Outhaul out to band – max tight.  Tension halyard or cunningham hard to keep draft forward.  Tension lower shrouds to keep mast from bending too much.  Backstay on very tight.  Top batten should be outside of parallel.  Tension the vang tight enough so that the boom does not go up when the mainsheet is eased. This will allows you to “vang sheet” to keep boat on its feet.  Remember, flat is fast.  Play the mainsheet aggressively in the puffs to keep the boat flat.

JIB

Tighten halyard quite tight to keep draft forward.  Trim sail so it is 3-4” off end of spreader.  Tighten backstay very tight to make headstay as straight as possible and flatten sail.

*Please note that the above trim settings should be taken as starting points only.  These are meant to show the range of settings from light to heavy air.  We have found it useful to keep a logbook every time we go sailing to note fast settings or ideas.

Harbor 20 Quick Tuning Chart – California

UPPERS LOWERS
WIND SPEED
Knots
UPPERS
(PT1)
LOWERS
(PT1)
Steps Turns from  base* Steps Turns from base* VANG OUTHAUL JIB LEAD
< 6 -4 -2 – 2 -4 – 2 -2 0 3” Lower
6-8 -2 -1 – 2 -2 – 1 -1 0 2.5” Lower
8-10 20 10 BASE BASE BASE BASE Snug 2” Neutral
10-13 2 1 2 2 1 1 Snug 2” Neutral
13-16 4 3 2 4 2 3 Tight 1” Neutral
16 – 19 5 4 1 5 1 4 Tight Max Upper
19-22 6 5 1 6 1 5 Tight Max Upper
22+ 6 6 1 6 1 6 Tight Max Upper

* The number of turns is an estimate and could be different from boat to boat. It is important to check your settings, and the number of turns between the settings, before going out on the water.

Harbor 20 Quick Tuning Chart – Chesapeake Bay

UPPERS LOWERS
WIND SPEED
Knots
UPPERS
(PT1)
LOWERS
(PT1)
Steps Turns from  base* Steps Turns from base* VANG OUTHAUL JIB LEAD
< 6 -2 -1 – 1 -2 – 1 -1 0 3” Lower
6-8 14 10 BASE BASE BASE BASE Snug 2.5”+ Lower
8-10 2 1 2 2 1 BASE Snug 2” Neutral
10-13 4 2 3 4 2 2 Snug 2” Neutral
13-16 6 4 3 5 3 4 Tight 1” Neutral
16 – 19 7 5 2 6 2 5 Tight Max Upper
19-22 8 6 2 7 2 6 Tight Max Upper
22+ 8 7 2 7 2 7 Tight Max Upper

* The number of turns is an estimate and could be different from boat to boat. It is important to check your settings, and the number of turns between the settings, before going out on the water.

Class Experts

Alex Curtiss

Long Beach, California
Alex.curtiss@northsails.com

Eric Doyle

San Diego, California
eric.doyle@northsails.com

Will Welles

Portsmouth, Rhode Island
will.welles@northsails.com