Albacore Sail Tuning Guide - North
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The following suggestions are meant to be a guide and should not be
misconstrued as being the only way to make your boat go fast. There are many
variables in yacht racing and we can only offer information that we have found
to work for ourselves, but for your crew weight and the various wind and water
conditions a slightly different approach may be in order. This guide is a very
good starting point but what ever makes you go fastest is best. We always
encourage sailors to keep good records of their racing experiences so that good
settings can be repeated and bad ones avoided for future races. Mark your
sheets and halyard for reference so that your notes are easy to translate into
fast settings.
This tuning guide features a table of settings for most wind and water
conditions but for the 300-330 lbs. crew. If you are lighter you may want to
de-power sooner and if heavier stay powered-up longer. Again experiment and
find out what works best.
BEFORE STEPPING THE MAST:
1) Centreboard Pin: Centre of the bolt should be 254 cm. from the transom.
2) Mast Step: The aft pin in the mast step should be 74 cm from the centre
of the C/B pin.
These two measures are important for determining the balance of your boat.
For example, if the C/B is too far forward you will create weather helm, and the
opposite is true if the C/B is too far aft. You must "feel" your boat
to determine how your helm is. Excessive weather helm is bad but a little is
needed to maintain a feel for the boat. How much you need to "feel"
is your call. Remember the less you need to pull on the helm the less drag you
will be creating.
3) Spreader Angle: The spreaders should be 43 cm long and be set at an angle
such that the distance from the straight line between the shrouds to the back of
the mast should be 19. cm. Be sure that each spreader is adjusted identically
to the other. Once your mast is stepped we can double check that the correct
pre-bend has been applied and fine tuning can be done from there.
4) Check that your shrouds are of equal length. The smallest difference
will cause your mast to bend sideways.
5) Check that all your sheaves are clean and lubricated.
AFTER STEPPING THE MAST:
1) RAKE: There are various methods of measuring rake. The following method
works on many hulls but if it seems a bit 'far out' on your boat another method
may be in order. Future editions of the North Albacore tuning guide will
feature 3 ways to measure rake depending on what type of hull you own.
Mast rake controls the centre of effort. If the rig is too far forward,
neutral or leehelm will occur. If the rake is too far aft, weather helm will
occur.
Hoist the jib and tension the halyard to approximately 200 lbs. Disconnect
the forestay and swing it back to the black band at the gooseneck on the mast.
Mark the forestay at the height of the top of the black band. Now reconnect the
forestay and measure down the forestay from the mark to the attachment point at
the deck. The distance we want to get is 86 cm. Adjust the shroud pins to
achieve this amount. For Ontario Yachts hulls this measurement should be 75 cm.
2) Check your Pre-Bend (Spreader angle): Before you stepped your mast we set
the spreaders up at a certain angle. What we are trying to achieve with spreader
angle is the proper amount of pre-bend. Pre-bend is the amount of aft curvature
in your mast when the rig tension is on but without sails up. Pre-bend is
measured by the distance between the straight line from the tip of the mast to
the gooseneck and the back of the mast at the spreader mount (Use your main
halyard as the straight line). The proper amount of pre-bend with new sails is
1 cm. As your sails get older (mid fuler) you ran increase the prebend to 2 -
2.5 cm to help control your growing sail from getting too full.
If, once you've loaded the rig (i.e. have your jib up and its tension
applied to 200 lbs,) and you find more or less pre-bend then you must fine tune
your spreaders. This may be because your chainplates are not in the same
position as ours, your spreaders are not the length we recommend, the height of
your spreader bracket is different or your mast step position is out. Sweeping
your spreaders aft increases pre-bend, sweeping them forward reduces it.
If you have no method of adjusting your spreaders you should consider a way
as proper spreader adjustment is crucial for proper mast trim and subsequently
sail trim.
3) Check that your mast does not move from side to side in the mast gate, If
it does affix plates to your gate to make it a snug fit. Allowing movement lets
your mast bend sideways and this is not fast.
4) Sight your mast to ensure it doesn't bend sideways.
If it does: 1: Are your shrouds the same length?
2: Is your mast fitted evenly from side to side in the gate?
3. Are your spreaders adjusted identically?
4: Is your mast permanently bent?
POSITION OF JIB TRACKS:
Front of jib track (in relation to C/B pin)........... 0 cm
Length of jib track.................................. 30 cm
please note that on some hulls including Ontario Yachts built Albacores the
front of the jib track should be approx. 10 cm aft of the pin
NOW WE CAN GO SAILING:
All the adjustments listed below are important to the performance of your
North Sails. Read about the use and effect of each adjustment and then refer to
the table on the last page to find out how to set each one for the given
condition.
RIG TENSION-. Rig tension controls the amount of luff sag and lateral mast
bend. In light air or choppy conditions when power is needed we allow more jib
luff sag which make the jib fuller and thus gives the boat more power, In heavy
air we apply lots of rig tension to reduce jib luff sag and depower the jib by
making it flatter.
JIB LEAD: Jib lead position affects the fullness and twist of the jib, and
also the slot between the main and the jib If the lead is too far forward the
jib becomes too full and the twist is reduced thus closing the slot. This is
poor. If the lead is too far back the jib becomes very flat and the leech
twists open, The slot in this case will be overly open and may be de-powering
the boat too much. We want to close the slot enough to generate maximum power
while not stalling the sails or overly backwinding the main. If the boat just
isn't moving well you may have the lead too far forward, If the main looks good
but you're not pointing well the lead may be too far aft.
CUNNINGHAM: The Cunningham moves the draft position in the sail. As the
Cunningham tension is increased the draft is pulled forward, straightening the
leach and decreasing the heeling force, If the wind drops and the cunningham is
not released this can seriously hurt performance. A simple rule of thumb is to
use none until 11 knots and above 11 knots apply enough to just remove the
wrinkles in the luff area.
BOOM VANG: Boom vang controls mainsail leach twist and mast bend. Vang
tension bends the mast and flattens the main (de-powers it). It should be
adjusted as the wind changes. If the vang is on tight and the wind drops be
sure to ease it to maintain good mainsail trim. Be sure to use no vang when
sailing to windward in conditions below 11 knots
PREBENDER/RESTRICTOR: Prebender is used in very light air to help flatten
the main when excessive power is not needed. As the wind rises less prebender
will be needed when at 8 knots the, mast should not be prebent at all. In most
conditions the, mast should be allowed to float freely, for and aft, in the gate
so the mast can be bent using the vang as the wind rises. In 8-11 knots and very
lumpy seas restriction may be needed to increase the power of the main while the
vang is applied. Restricting the mast low down keeps the main fuller and more
powerful when extra punch is needed
OUTHAUL: Outhaul controls the fullness of the bottom half of the main. The
tighter the outhaul the flatter the sail. The foot of your North main has a
shelf. Under NO circumstances should this shelf be open when sailing to
windward.
If you would like any further information on rigging your
Albacore or the rigging of any new equipment please write or call us.
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