The purpose of this tuning-guide is to give our clients in the Dragon
class some guidelines on how to get the most out of their North Sails.
The tuning-guide was compiled by Jørgen Schönherr, Poul Richard Høj
Jensen and Theis Palm.
Always experiment and try finding your own trim using these guidelines.
The weight of the crew, the balance of the boat, the stiffness of the
mast together with specific local wind and sea conditions all have
influence on the fastest and final trim.
Before stepping the mast in the boat, some very important measurements have to be checked to follow this tuning-guide correctly:
Lead the upper shrouds and forestay along the mast, the upper
have to be out of the spreader tips. Pull them as hard as you can and
put a mark on all three wires at the top at the black band on the mast
(it is 80 cm above deck level). These three marks are now used to check
if the mast is straight from side to side in the boat, and to check the
All measurements for the mast position is made from station 4,
(you find station 4 between the forestay and the mast) which is marked
on both port and starboard side of the hull with a dot. Draw a line in
between the points. From the middle of this line to the front end of the
mast (without spinnaker pole track) See the distance in the on the
water tuning guide below.
The mast rake is set by first fixing the forestay on the deck
1,86 cm from the front side of the mast. (This is the max. distance
allowed in the class - rules). Then measure the distance from the black
mark on the forestay to the deck (along the forestay). See the distance
in the on teh water tuning guide below.
The upper shrouds proper position is located measuring
perpendicularly from the line on station 4 to where the shroud enters
the deck. See the distance in the on the water tuning guide below. For
light crews (220-240 kg) we recommend to leave the shrouds one hole
The lower shrouds are placed in the hole just behind the top
shrouds (approx. 3 cm), so that they don't hold the mast back when going
The marks on the top shrouds (from step 1) are now used to
control if the mast is placed in the middle of the boat. This is done
best by measuring the distance from the mark to the deck. This should be
the same on both sides. It is very important, that the mast is straight
from side to side and not being distorted at deck level.
Setting up forestay tension, put the mast in strong wind
position (tension 20 on the uppers and 8 on lowers). Next, put the
tension gauge on the forestay around the black mark. Pull runners until
the gauge reads 30. Make tape on runner exit above deck. Do the same on
the other side. Now you are sure both runners have the same tension on
the mark set-up. When you ease the runners until the forestay is just
tight, the tape mark will be 15 cm above the deck as the uppers are both
the same length.
The jumpers are adjusted by pulling the permanent backstay.
Then look up along the sail track and check that the jumpers are equally
tight on both sides. If this is not the case, they should be adjusted
till the mast is completely straight.
All rig tension measurements we have used a Loose Gauge PT-2M.
To get a more precise reading, cut the plastic of the upper shroud
about 1.2 m above deck. You find all setting in the chart on the other
The lower shrouds are tensioned, so that the mast is
completely straight in the boat up to 20-22 knots. From here on tighten
them till the mast drops 5-10 cm off to leeward where the forestay meets
the mast - the exact measurement is dependant on crew weight.
Please see the Dragon On the Water Tuning Guide!
Good luck on the water!
Contact the Dragon Experts: