9
MAINSAIL TRIM
Perry Lewis, (l), of North Sails
Midwest with Bob Alice, (r), owner of
J/35 MIST APPROACH reviewing
Bob‘s onboard sail log and racing
notes. Keeping a photo log of your
sails will provide you with a
“sailmakers eye” for trim, shape,
draft position, mast bend, rig tension
and headstay sag which helps to
repeat fast settings. A log is a great
motivational tool to keep the crew
involved, especially when gearing up
for the new sailing season.
Maintaining a log is especially
helpful to your sailmaker when
evaluating your sail inventory. Notes
on wind speed, wind angle, number
of hours and your comments are just
a few suggestions of items to
include.
On the next page are photos of the
mainsail and genoa taken from“the
trimmers view” to give you an eye for
max speed set-up. Your North
sailmaker can show you how to
measure chord depth and draft
location of sail photos taken from the
correct angle. In most cases, a
disposable camera kept onboard is
sufficient for all the pictures you
need to keep a sail log.
3DL 12600 dpi set-up for 12 true, flat water at the Newport NOOD Regatta.
The sail is sheeted very hard for highest pointing angle. All telltales are flying
and there is no backwinding present.
The same mainsail as above, but note the backwinding. This is caused by two
things; genoa trim and traveler position. In this photo, the genoa is sheeted
extremely hard. The backwinding is not hurting performance...yet. You can
minimize the backwinding by setting-up the mainsail flatter with the traveler
positioned high. The top batten is beyond parallel by two degrees. Tighter
headsail trim minimizes the slot and reduces twist. As a result, the sail sets
straighter vertically, without closing the leech and applying the ‘air brake’. Try
this in 8-14k true, no chop, no pitching. And don‘t forget to hike hard!
J/35
Tuning Guide
TWS
12 knots True
Top
15% @ 44%
Middle
11.9% @ 52%
Bottom
8% @ 49.6%
TWS
12 knots True
Top
14.3% @ 52%
Middle
12% @ 51%
Bottom
8% @ 53.6%
