Club FJ Tuning Guide

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The following measurements are those we have found to be the fastest for your new North sails. We urge you to set your boat to these specifications when tuning your boat. This will help you achieve consistency in boat speed, and will serve as a basis for future tuning. If you have any questions or problems or are not able to get your boat to match up these specs, please feel free to contact our CFJ experts.

Onshore Adjustments

Step 1
Before stepping the mast, check the length of the spreaders. MEasure your spreaders from the point where the shroud runs through the tip to where the spreader butts up against the side of the mast. This measurement should be 16 1/2 - 171/2 inches.

Step 2
Check the butt position of the mast. This is measured from the centerboard pin to the back of the mast extrusion itself and should be 18 - 18 1/2 inches.

Step 3
Step the mast and attach the forestay to the stem plate in the 2nds hole back.

Step 4
Attach the shrouds in their respective chainplates so the rig is just snug.

Step 5
Hoist a tape measure on the main halyard and measure back to the top of the transom at the back of the boat. With the rig leaning back on the forestay and the shrouds snug, this measurement should be approximately 19'4" to 19'6".

Step 6
With the tape measure still attached to the main halyard and the shrouds taught, check the lateral straightness of the mast by measuring down to the rails on opposite sides directly across from the chainplate. If the difference is more that 5/8", readjust your shrouds accordingly.

Step 7
Hoist your jib and tension the halyard until the measurement at the transom becomes 19'11". Basically, we are inducing 6-7 inches of "rig-tension" into the boat. The rig should be quite tight and tight enough so that when you are sailing in winds up to 12 mph the leeward shroud remain snug. Only in winds above 12 mph should the leeward shroud begin to go slack.

This rake measurement and rig tension are important for boat balance, mastbend, and jib luff sag. The rig tension helps control the mast bend correctly as well as minimize luff sag in the jib. These two functions will effectively control the shape of the sails so there will be very few adjustments needed to trim your North sails for top speed. The rake measurement and mast butt position have been selected for proper helm balance and jib lead position.

Sail Adjustments

Main Cunningham
For the main halyard/cunningham it is best to leave a hint of horizontal wrinkles from the luff of your main nearly all times. In a breeze when the boat is overpowered, you may tension the main halyard and/or the cunningham to just barely remove all wrinkles and have the luff be quite smooth.

Outhaul
In light winds it is best to pull the outhaul tight enough so there is a hint of a horizontal crease in the foot of the main parallel to the boom. In medium winds (above 5 mph), pull the outhaul tighter so that the crease is apparent. In heavier winds (above 12 mph), pull the outhaul very tight so that there is a hard crease in the main just above the boom.

Jib Sheet Trim
Unfortunately, there is no easy guide for jib trim. We are looking for a parallel slot between the exit of the jib and the entry of he main. A guide that has been used is to imagine a batten on the jib at mid leech. The "batten" is usually set parallel to the center line of the boat, making the upper batten of the jib twist outboard slightly and the lower batten twist inboard slightly. It seem that 90% of the time boatspeed problems are due to a faulty jib sheet trim. Much of the faulty trim is caused by an undertrimmed jib.

Jib Lead Placement
Your North CFJ jib is designed so that the lead should be placed close to the center of the track when the boat is tuned with proper rake. To fine tune this position, luff the boat slowly into the wind with the jib properly trimmed, as above, and note how the jib luff breaks. If the jib luff breaks higher first, move the jib lead forward until the break is nearly even. If the jib breaks lower first, move the jib lead aft, again until the break is even. The "break even" luff position for your jib is proper for all wind and sea conditions until it is blowing over 10-12 mph. At this point, or when the boat is overpowered, move the jib lead progressively aft until a maximum aft position of 2" aft of the "break even" position is achieved. At this point the jib will be breaking earlier, higher as the boat is luffed up into the wind.

Mainsheet Trim and Boomvang
The mainsheet should be pulled tight enough so that the last 18" of the upper batten becomes parallel to the boom on a lateral plane. This is sighted from underneath the boom looking up the sail and lining up the batten and the boom an that plane. In light winds it is impossible to keep the upper batten from hooking slightly to windward because of the weight of the boom hanging on the leech of the sail. In choppy conditions, or after a tack, ease the mainsheet approximately 6 inches to help open the upper batten slightly past parallel to the boom.

When the boat becomes overpowered, the boomvang is used hold the boom down and keep the upper batten parallel to the boom. It also induces a great amount of mast bend and will help to flatten out the sail. At this point, the mainsheet can be eased so that the boom will move to leeward and depower the boat. The heavier the winds, the heavier the boomvang tension.

Downwind the vang should be trimmed enough to keep the boom down and the leech set with the upper batten parallel to the boom. There is a telltale placed on the upper batten on your North mainsail which should flow straight off the leech when the boomvang is set properly downwind.

Spinnaker Trim
Your North CFJ spinnaker should be set so that there is 5-8 inches of curl in the luff of the spinnaker at all times. Try to avoid over trimming the spinnaker and closing the slot between the main and the chute. The halyard should be off the mast approximately 5 inches at all times, and the pole set so that the two ends are parallel to the deck. If the spinnaker breaks high first, check that the pole is not too high, and if the spinnaker breaks low first, be sure that the pole is not too low.

We wish you good luck and fast sailing!

For more information on CFJ tuning, contact the North Club FJ experts.