Challenger Sail Tuning
Basic Principles
· A different shape is needed for
light, medium and heavy winds.
· There are also different settings
for Upwind and Downwind
· You can tell if the shape and trim
is right when:
v Telltales stream horizontally most
of the time
v The helm feels light and balanced.
v Sheet tension increases as you pull
it in.
v You are going faster than the
opposition in a race.
· Battens - only need to be a snug fit
in the sail pockets. Excessive tension makes them hard to tack but make sure they
are properly seated at the front of the sail, otherwise they will rip out the
side of the pockets.
· Controls - lines should be as thin
as possible and pulleys large. This gives less friction and a lighter pull.
· Easy movement of the sail corners
and edges is important. Edge groove lubrication and ball bearing controls make
settings more precise.
· Fast sail settings should be marked
on the spars so that they can be reproduced easily.
How to Use the Sail Controls
Because the boom is sloping,
tensioning the downhaul will also tighten the foot of the sail, which reduces
its depth and depowers it. The sequence in which the sail controls are adjusted
is therefore an important factor in controlling the sail shape and performance.
Initial Setup for the Beat
1.Pull on the tack downhaul to
the required luff tension.
2.Then, pull the foot outhaul
to give correct foot depth
3.Then, set the kicker to give
the correct leech tension/mast bend
4.Then, pull the sheet in and
go!
Going from Upwind to Offwind
1.Ease the kicker to the
required setting. This can be done before letting the sail out as tension will
be maintained by the mainsheet
2.Then, slacken the tack downhaul
the required amount. This should be done before bearing away, as luff tension
will be maintained by friction in the mast luff groove.
3.Then, the foot outhaul will be adjusted automatically but may need more depth in some circumstances.
Light Winds - The sail should be smooth and flattish with no sharp curves. There should
be a straight flow at the leech, with maximum fullness 40%-50% back from the
mast, about in line with the front of the Challenger symbol.
§ Downhaul - Just enough tension to remove
creases from the luff, any more will pull the maximum fullness too far forward.
§ Outhaul - Maximum foot depth should be
8-10cm [a hand width] from the boom.
§ Kicker - Pull on until the top leech
telltale just stalls when sailing, with the other two flying.
Sheet - The boom should be about an arm’s length outside the cockpit.
Medium Winds - The sail should be as full as possible, curving
from luff to leech with maximum fullness 40% from the mast.
§ Downhaul - Little or no tension. Only used
to make the bottom of the luff straight if it starts to sag. Pull on more
tension if the wind rises and starts to blow maximum fullness further back in
the sail [when this happens, the helm will feel heavy and sluggish]
§ Outhaul - Maximum foot depth should be
14-16cm [a hand’s length] from the boom.
§ Kicker - 2/3rds on for maximum leech
tension, more if you are not pointing as high as other boats. The top batten
end should be roughly parallel with the boom.
§ Sheet - The boom should be about 2/3rds
of an arm’s length from the cockpit, with the end over the corner of the
transom.
Heavy Winds - The sail should be progressively flattened with
maximum depth kept 35-40% from the mast. It should twist off at the top, to
spill wind in the gusts.
§
Downhaul - Progressively harder on, until
almost on the boom. Pull with both hands if it’s really windy, until the helm
feels balanced.
§ Outhaul - Start with 14-16cm foot depth to
keep maximum drive low down. If overpowered, gradually reduce depth to 8-10cm.
§ Kicker - Full on, to bend the mast but
ease to release leech tension and spill wind in gusty weather.
§ Sheet - Should be progressively eased as
the wind rises, to reduce leeway and keep the boat moving. The boom can be over
an arm’s length out, as it is more important to keep the boat moving than to
point high, especially in waves.
Light Winds - The sail should be fuller than for upwind with some twist. The shape
should be fine-tuned on the reach to get as many telltales to fly as often as
possible, which shows a smooth and even wind flow over the sail. The order
below is how the controls should be adjusted:
§ Kicker - 3/4 off to give fullness with a
flattish run back to the leech and some vertical twist.
§ Downhaul - Off, or a little tension to
remove creases from the luff.
§ Outhaul - May need easing slightly, so that
maximum foot depth is 14-16cm from the boom.
§ Sheet - Ease whilst rounding the mark so
that telltales keep flying. Make sure the boom is out at 90 degrees for the run
for maximum projection of the sail area.
Medium Winds - The sail should be very full with plenty of twist.
Luff creases don’t matter.
§ Kicker - The fully-off position is
designed to be the automatic medium downwind setting.
§ Downhaul - Fully off
§ Outhaul - May need easing so that maximum
depth is 18-20cm.
§ Sheet - Try to lean the boat to windward
as you bear away and let the sheet run out freely as you turn to minimise any
resistance. Constantly check and retrim on the reach to keep the telltales
flying. Aim to run dead downwind or trim to run by the lee to try and encourage
a smoother airflow over the sail.
Heavy Winds - The sail should be a little fuller than for upwind
but needs twist to spill wind in the gusts and stop the bows digging into
waves. Any fullness should be lower down in the sail for maximum drive.
§ Kicker - 1/4-1/3 on
§ Downhaul - Off but, as winds get stronger,
enough tension to pull out luff creases and keep the maximum fullness in a line
down from the front of the Challenger symbol. When it’s really strong, lots of
tension will flatten the top of the sail and let it spill wind.
§ Outhaul - Don’t ease. Releasing the
downhaul will also slacken the foot and give enough extra fullness for offwind
sailing.
§ Sheet - Constantly adjusted. Keeping speed up is more important than flying the telltales. Ease and bear away in heavy gusts. To avoid damage, ensure the boom cannot go more than 45 degrees forward of the mast.