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North Sails J35 Tuning Guide (1.6MB)
North Sails J35 Tuning Guide
Time in the boat and race participation are two of the best methods of gaining experience in class racing. After 3 vears 'in the boat', we at North Sails East have amassed a wide range of information on the J35. This comprehensive tuning guide provides up-to-date specifications on boat setup, rig tuning and crew preparation. We have also added a reprint of an article written by Andreas josenhans which appeared in the January 1990 issue of Sailing World. It contains detailed information on sail selection and changing gears to suit the sailing conditions from light to heavy air.
Our team of sailmakers, designers, and active racers at North Sails East are proud of our association with the J35 Class. Our continuing role in the class is to lend support to you and provide the fastest, most durable sails. Please feel free to call us if you have any questions or wish to discuss your goals for the upcoming season. Sail Fast! Sail Smart!
- Andreas Josenhans
- Jody Lutz
- Blake Marriner
- Chris Steinfeld
- Brian Hayes
- John Schnorr
Before vou step the mast
Use this as a checklist to ensure that your rig is set-up properly before stepping the mast.
- Set the forestay to 48'11".
- For 12 knots or more shorten the forestay to 48'9". Pin to pin.
- File all spreader ends so they are smooth and cannot cut the sails.
- Clean and lube all turnbuckles.
- Move mast collar max-aft, remove plastic collar and shim aft.
- Shorten the backstay 5 to 8 inches.
- Move mast butt max-forward, after lubrication of step and bolts.
- Attach shrouds to chainplates so the upper shroud is outboard aft, the lower is forward and the D2 is inside Aft.
After you step the spar
- Mark genoa leads every 6" equally on the port and starboard side.
- Center the spar with the main halyard to the cap shrouds.
- Tension the caps 18 complete turns after they are snug.
- Tension the second diagonal shrouds hand tight.
- Tension the lowers 4 turns beyond hand tight.
Trimming your North J/35 Sails
It is very important to mark all your shrouds, sheets, tracks, outhaul, backstay, etc. Also, it's good to keep records of tuning set-up, the conditions you sail in and boat speed. You want to be able to duplicate settings from race to race. And also know exactly how the boat was set up when your boat speed and trim were at the optimum settings for the conditions you were racing in.
Mainsail Trim
Trim the mainsheet hard enough to make the top batten parallel to the boom. You can check this by sighting from beneath the boom on a vertical plane.
Once the boat has accelerated and you want to point higher, trim the sheet harder to tilt the top batten slightly to weather. If the mainsheet is too tight (the top batten will hook to weather) your boat speed will fall.
In light air and choppy water the top batten should be parallel or twist off slightly.
Use of the traveller
Pull the traveler car to windward in flat water until the boom is above centerline by 6". To check this, put a mark on the center of your stern pulpit and have your crew sight aft along the boom. Keep the boom on centerline up to 10 knots and lower for rough water. As the wind increases above 10 knots, gradually drop the traveler to keep helm and heeling under control.
The lens foot - the mainsail panel closest to the boom, should not be fully open while sailing upwind. Use the following guidelines to set your outliaul tension properly:
Apparent Wind/Outhaul Tension
- 0 to 5 eased 1.5"
- 6 to 10 eased 1.0"
- 11 to 14 eased .5"
- 15 maximum
Cunningham
The Cunningham is used to position draft in the mainsail. You should try to keep the maximum draft point 50% back in the sail. In a new sail no Cunningham is needed up to 6 knots. At 7 to 14 knots use enough to remove most of the wrinkles, and tension as the wind strength increases. In heavy air, you should not have any wrinkles. Pull the Cunningham very hard above 18 knots to move the draft forward in the top of the sail.
Backstay
As the wind increases above 7 knots, we tighten the backstav correspondingly.
Pulling on the backstay does two things.
1. As the mast bends, the upper half of the main flattens and the leech opens reducing helm and angle of heel.
2. It makes the forestay tighter which flattens the entry of the headsail and eases the leech --- so you can point higher and reduce heeling angle.
Since pulling on the backstay has a large and immediate effect on main leech tension, wi-ienever you adjust the backstay you should adjust the mainsheet. Adjust your backstay tension using the following guide.
Apparent Wind/Backstay Tension
- 0-6 -- Minimum
- 7-10 -- 1/4
- 11-14 -- 1/2
- 15-18 -- 3/4
- 19 -- Maximum
Runner
Runner makes the mainsail deeper, pull to make the sail flatter, ease to make the main fuller. (Editor note: I believe this is stated backwards.)
Boat Set-Up & Racing-Tips
In addition to the tuning guide, you can also use the racing tips listed below as a check-list prior to the start of the race. We use this list constantly as a reminder that the boat and crew should always be race - ready. You may already incorporate manv of these ideas as routine r)ractice aboard your boat.
If you don't, you may find that extra one-tenth of a knot speed advantage which could be the difference between crossing the finish line first or second.
- Try to keep people out of the cockpit while racing. A maximum of 3 people in the cockpit will be an advantage to overall weight distribution.
- Don't sit aft or up on the dog house. The optimum crew location should be: 1 person helming, 1 person trimming the jib and 1 person calling tactics and trimming the main. The rest of the crew should be sitting close together forward on the weather rail, "cheeks to the teak". Crew members should never stand in front of the helmsperson.
- Instruments should be located under the boom, large displays work particularly well.
- Stow sails on the floor, and keep any excessive weight out of the ends. Don't store any gear in the quarter berths.
- Sliding cars work more efficiently than the old style genoa tracks.
- Here are two points to remember when flying the spinnaker:
- Keep clews level at all times (this takes practice)
- Don't let the pole jump around, keep the foreguy snug!
- Clean, clean, clean the bottom of the boat to go fast.