North Sails 1998 Express 27 Tuning Guide

by Scott Easom


Hello, my name is Scott Easom. I own a San Francisco company that specializes in making people and boats sail faster. While I sail with many high profile clients on their boats for a living, when it comes time to enjoy myself and do my own thing, I like to sail the Express 27. I've worked closely with North Sails since 1985 regarding the 27. Numerous changes have been made since the first edition. The crew weight issues have had the largest impact on the boat itself. My team has by far compiled the most championships sinec the inception of the class, winning in both light and heavy conditions. While the following information will help, there is no substitution for time on the water, so go sailing whenever possible and use North Sails.

I understand it's difficult to cover everything in detail, so if you can call me or E-Mail me for further details it woulbe be a pleasure to talk to you personally.
(415) 453-5461

The Basics

In order to duplicate the setting offered in this guide, I must assume that your Express 27 has been fitted with "inline lower shrouds". These are imperative and must be installed before we can proceed. They are that important. The San Francisco Fleet also sails with a crew weight limit of 880 pounds. So these numbers are predicated on a crew weight that is similar.

Boat Set Up

As with any light displacement boat, we sail only with the minimum required equipment. It's important to be as light as possible. Keep what weight that is on board centered over the keel in the light to moderate conditions (0-12 Knots). As the wind builds above that figure, start sliding sails and equipment aft. Never put anything in front of the main bulkhead while racing. Like any other racing boat, weight in the ends will make the boat pitch.

The "get light" philosophy is everywhere on board.

Spinnaker Sheets 3/16" Spectra to a 3/8" cover
Genoa Halyard 3/16" Technora with a cover at the winch
2:1 Main Halyard 3/32" Spectra with a cover at the cleat
Twings 3/32" Spectra with cover at the cleat
Mainsheet 3/8" Spectra Lite tapered to 5/16"
Genoa Sheet 3/8" Spectra w/ small Sparcraft Presslocks spliced on
2:1 Foreguy 3/16" Spectra
Topping Lift 3/16" Spectra
Spinnaker Halyard 3/16" Spectra tapered to 5/16"

We also only drink Lite Beer!

Sail Inventory for San Francisco Bay

*denotes what sails I personally use

Dacron mainsail This is a great sail and has the widest range.
*3DL Gran Prix Aramid Cost more at first but last 2-3 times longer than conventional sails.
*3DL 155% Light/Medium REGATTA Aramid Huge range. A weapon in the light to moderate. Suprisingly good top end.
3DL 153% All Purpose REGATTA Aramid This is our class sail. Good all around performance.
*3DL 150% Heavy REGATTA Aramid New sail with ample leech hollow and very straight leech. This sail is really tilted toward places with predicatble breeze like San Francisco.
Class Jibs  
*3DL Class Jib REGATTA Aramind Gatorback Kevlar Class Jib
*.6 oz Poly Spinnaker Code 2S
*.85 oz Poly Spinnaker Code 3S

Rig Tuning

This is an area thae we continue to this day to play with. When the crew weight changed to 880 pounds from 1000 pounds, we sailed the boats differenetly in the upper ranges and the sails were flattened. During the 1997-98 mid-winters we have been changing our rake numbers from race to race. We are now very happy with the numbers that we have settled on this year.

Tuning the rig is easy but hard to be precise since you can't use a Loos Gauge on the rod shrouds. Fortunately, we have found that the rig tension, as long as the mast is straight, is not that critical. The most important number is the rake number.

To start the tuning process, we must first make sure that you are in the ball park with your rake number, which is really your headstay length. To get our rake number, take the backstay and pull it on 50%. Then, take your jib halyard to the deck in front of the mast, touching both the deck and the mast step base. Cleat it there. Sometimes you have to cleat it off a half inch shy so you can pull down harder to get rid of stretch and the effects of wind on the halyard. Then swing the halyard to the headstay. Mark the headstay at that precise point. Then with a tape measure, measure from the mark on the headstay to the center of the headstay pin at the stem fitting. The number is 27". That is the number that with much experimentation has been the best throughout the range. If you want to go faster but sacrafice pointing, use 26". The boat is very sensitive to small changes in the rake number.

Now you can go ahead and tune the mast. To start loosen all the shrouds. Use the main halyard if it is wire to check the mast from side to side by taking the shackle from chainplate to chainplate. If you have a rope halyard, I suggest you hoist a metal measuring tape to the top. Use the uppers to center the mast. Then sighting up the mainsail groove, use the intermediates or D-2s to align the middle. Finally tighten the "in line lowers" to make the mast straight. To do the best sighting job, remove the main boom so you can put your eye on the mast as low as possible.

Disregard the aft lowers. They will be adjusted on a per race basis. Tight for upper ranges of the jibs and progressively looser for the lighter conditions. More on the aft lowers later.

Go sailing, look up the mainsail track and make final tweeks to the uppers. Don't forget to pin them after you are done.'

The aft lowers are adjusted on a per race basis. In the big breezes tighten the aft lowers so there is no low bend fore and aft. Simply pull the backstay to your 100% mark. Look sideways or athwartships up the mast, there should be no bend from the lower spreaders to the deck. By restricting mast bend, backstay tension is transfered to the headstay which flattens the jib or genoa. In light air, loose aft lower shrouds allow you to shape the mainsail without adding a lot of headstay tension. So, with loose aft lowers you can twist the top batten of the main and keep the headstay loose and the genoa powerful. Ronstan makes an integrated turnbuckle so you can fine tune these settings. My all purpose setting for the aft lower is 34 on the small Loose Gauge.

Jib and Genoa Leads

The Express 27 comes with one long fore and aft track that works well in light to moderate conditions. We installed a short length of track for the jib just inside the shroud chainplate for when the seas are rough. On our boat I removed the long track and installed two short lengths of track for the small jib. The inside track is where the stock track is located. The out board track is located just inside of the shrouds. The difference may only be 2-3 inches but it makes a big difference in chop, or the upper range of the jib.

Our genoa track is athwartships with a car that will slide in and out. A small line adjusts the lead up or down. This is the classic floating lead system. In these small boats, I believe that moving the lead car aft to depower doesn't work very well because it just sucks the foot into the shrouds and closes the slot. Moving the lead outboard, however, really allows me to let the traveler down and keep the boat on it's feet. This system works well for us, and it is light.

Sheeting of Sails

Light Winds (2-5 Knots)
Trim Round foot with upper leech 3" off upper spreader
Halyard Loose
Headstay Loose
Draft 50-55%
Traveler 8-10 inches above centerline which puts the boom on centerline.
Outhaul Medium
Cunningham None
Top Batten Parallel to boom
Heel 5-10 degrees
Other Information
Crew Weight Forward to the shrouds or better yet down below.

Medium Winds (6-12 Knots)
Trim Round foot with upper leech 2" off upper spreader
Halyard Loose to Medium
Headstay Loose but not bouncing
Draft 50%
Traveler 5 inches above centerline with boom on the centerline
Outhaul Loose
Cunningham None
Top Batten Parallel to boom with top telltail stalled 50% of the time
Other Information
Heel As little as possible

Moderate Winds (13-16 knots)
Trim Medium foot round with upper leech 1-1/2" off upper spreader
Halyard Medium to Tight
Headstay Tight
Draft 45-50%
Lead At the top end, aft or outboard. Open Slot.
Traveler Centerline
Outhaul Tight
Cunningham Remove wrinkles in main luff
Top Batten Parralel
Other Information
Heel As little as possible
At the top end of the genoa it's better to pull the traveler up and twist the main. It's OK if the main washes out every so often. Never traveler down and sheet hard.

Breeze On (17-22 Knots)
Trim Keep full foot round.
Halyard Tight
Headstay Tight
Draft Forward
Lead Use the outboard lead if the sea condition is rough.
Traveler Centerline
Outhaul Tight
Cunningham Tight
Top Batten Parallel to open. Moderate sheet tension. Twist is good.
Other Information
Heel Hike till it hurts

San Francisco Breeze (22-30 Knots)
Trim Maintain some foot round
Halyard Tight
Headstay Tight
Draft Forward with the top well twisted.
Lead One hole aft on the outboard lead if you have one.
Traveler Center to 4" down
Outhaul Maxed
Cunningham Tight
Top Batten Open
Other Information
Heel Hike really hard!
Again avoid the big boat syndrome i.e. Traveler down sheet on hard. The traveler should be just below center, the sheet eased, the backstay on 90%, and the main washing out 50% of the time. Play the traveler and avoid excessive weather helm. This takes some practice, so keep trying.

Down Wind
Light Weight forward. Bowman forward of mast and any extra crew below to stabilize the boat. Sail angles. Helmsman should drive forward of the traveler.
Medium Weight forward. Bowman forward of mast while running. Pull the righ forward with the jib halyard. This may cause a slight inversion with a tight aft lower shroud. Press on.
Heavy Pump, Pull, Yank! Basically try to tear it all apart for maximum speed in plaining conditions. Move the weight aft to keep the bow up.

I hope this will help you find the groove faster.
Have fun, sail fast.


Scott Easom / Easom Marine