Heiko's trim instructions

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The 2.4mR is a trim-sensitive keel boat. Even small mistakes often have a significant impact on the speed and / or the height of the wind. It is therefore very important to know the basics.

When I started sailing with the 2.4mR, I downloaded Rickard Bjurström's trim instructions from the class's international homepage. In principle, I still think that this trim guide is very good.

So this text is a German summary mixed with my own views.

Das Boot

In principle, all Norlin MKIII have the same hull shape. There are differences in the design and the resulting differences in stiffness and weight. You should try to make the hull as light as possible.

I have no seat in the boat and can therefore drive the maximum keel weight of 181kg in the keel. This brings more straightening moment (less heeling on the wind) and thus more height and speed.

The fuselage - or the foam in the bow and stern tends to absorb water. It is therefore very important to ventilate the boat well and park it in the sun.

The foam in the 2.4mR absorbs up to 6 kg of water!

The equipment

Everything on the boat has to run and work smoothly. All pods and stretchers should be Dyneema with or without a jacket. Pods with a jacket, stretchers without if possible - unless they are occupied in clamps. Thin pods are more uncomfortable to hold, but also run better through the blocks. I prefer performance to comfort.

Basic rig settings

Mast foot

We start with the position of the mast foot. We measure from the aft edge of the stern across the deck, down to the point where the extended rear edge of the mast meets the mast foot rail. It may be necessary to remove the hand pump because it is in the way. The distance from the rear aft edge to the "meeting point extended mast rear edge - mast foot rail" should be 272 cm.

mast case

A measuring tape is attached to the major case and pulled upwards at most. The tape measure is then read from the rear edge of the tail. The mast fall should be 562-564 cm. The higher the keel weight, the further the mast can fall backwards. The shrouds are tensioned for measurement and the backstay is set very lightly so that the forestay and backstay do not sag. It is important that you tighten the eighth day before you measure and then loosen it again so that the forestay was once tense.

want voltage

It gets exciting here (little joke - but true). If you do not have a continuous adjustment, you have to adjust the tension before the run. That the mast must always stand straight (Bb - Stb) in the ship is a requirement!

Basically, the more wind, the more tension.

When there is little wind, the shrouds can be driven relatively loosely. 80gk tension is enough. From 10-12 knots, however, it means putting pressure on. Up to 230 kg are feasible.

Please remember that you have to open the levers before the wind to reduce the shroud tension. Otherwise the mast cannot fall forward. Opened levers must also be able to be closed again on the water. So try where your powers end.

Since I do not drive lower shrouds, I can say little about it. In principle, the lower shrouds should have significantly less tension than the upper shrouds.

Spreading sweep

The spreaders should only be a little aft. You measure the sweep by placing a (sail) crossbar on the upper shrouds and measuring the distance between the rear edge of the crossbar and the mast groove. A maximum of 25 mm can be set.

sail trim

We want to be as fast as possible in front of the wind and fast and high in the wind.

If the mast is right, we can take care of the sails.

I advise everyone not to buy exotic sails. A sailmaker who has never built 2.4mR sails that have had international success should not be selected. I myself use Faber & Münker Segel.

Mast and sail trim determine the balance of the boat on the cross. A badly balanced boat has rudder pressure, which makes it slow, drives less height and has more heel.

A well balanced boat has hardly any rudder pressure even in 25 knots of wind and drives relatively dry in the wind. A light tap on the leep pedal must be enough to sail straight ahead - otherwise something is rotten.

The balance in the boat is the perfect interplay of jib and jib. Pulling the backstay at rudder pressure is only half the solution to the problem.

In the following text, I therefore only consider Achterstag, Fock and Gross together.

Little wind 2 - 5 knots

The shrouds have little tension and the backstay is pulled a little to open the leech of the mainsail.

Be careful with the main sheet! The top batten from the mainsail should be about 10-15 degrees to the main boom. The less the wind blows, the harder it is to achieve. If you have a traveler, you can move it to windward. I don't have one - it works without it!

The lower leg should be tightened rather than bulged. If there is little wind, the flow in the big city breaks off very quickly.

The jib is raised with a bulbous position. The leech is about 15 - max 5 cm away from the spreader. It is important that when a small gust of wind comes in, loosen the jib so that the threads are in place and do not start immediately. We are sailing a keel boat that is only slowly gaining speed. Luffing directly would not bring a ride and hardly any height.

Light to medium wind 6 - 10 knots

The shrouds have medium tension and the backstay is only slightly tightened (the main sheet pull is enough to stretch the forestay). As soon as rudder pressure arises, the backstay is pulled closer.

The top batten of the main sail is parallel to the main boom.

Grosscunningham is loose.

The jib is relatively straight in the lower leg. The jib leech is near the spreader (approx. 6-5 cm).

Fockcunningham only slightly set

Medium to fresh wind 11 - 16 knots

Shrouds tight. Backstay increasingly denser (the rudder pressure decides !!!).

The top batten in the large folds out about 10 - 20 degrees (the more wind, the more).

Little Grosscunningham pull.

Jib is straight in the lower leg. The leech is on the saling.

Fockcunningham closer.

Fresh to strong wind 17 - 24 knots

Shrouds tight. Pull backstay until balance is reached.

Mainsheet remains tight up to 18 knots and is only opened above 18 knots.

Attention: The mainsail should not pierce or collapse (strong folds from the tree nock to the spreader area). So be careful with the backstay.

Jib is straight in the lower leg. The leech is on the saling.

Fockcunningham tight.

Strong wind to survival mode 25 - X

Pull on the back day until it is flat (no further !!!). Open main sheet until balance is reached. The large should not or only occasionally kill.

Jib is straight in the lower leg. The leech is on the saling. We need the pressure in the jib for balance.

Before the wind

Shrouds off. Mast forward. Loosen the lower leg somewhat. Grosscunningham on.

The tree catcher is adjusted so that the leech of the gross twists slightly.

Crossing in front of the wind. In other words, we rarely drive directly from behind with wind (180 degrees).

The less wind, the more pointed (approx. 165 gad) you have to drive.

The Grossbam is at right angles to the wind.

Always move the jib so that the current in the jib runs from the leech to the forestay. You can recognize this by the threads that you stick in the middle of the jib.

At the end

The right trim requires a lot of practice and feeling. However, it must also be measured and checked consistently. Markings on all stretchers are therefore absolutely necessary!

Enjoy

Heiko Kroeger

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5 Comments

  • Another addition to Heiko's extensive explanations. The sentence:… .If you don't have a continuous adjustment, you have to adjust the tension before the run. ….
    It is helpful to set two basic tensions on the thread of the upper shrouds (and possibly also the lower shrouds). This can be done very easily with two - self-locking - nuts. But here too - whatever needs to be adjusted on the water - should be tried out thoroughly beforehand. Nothing is "more surprising" than losing the shroud tension after unhooking an upper shroud.

  • Hello!

    “A measuring tape is attached to the major case and pulled up as far as possible. The tape measure is then read from the rear edge of the tail. The mast fall should be 662-664 cm. "

    I think this cannot be right. Rickard Bjurström says 560 cm and North sails 557 cm. I have 558 cm.

    • Heiko Kroeger

      Hello Harri,

      the different dimensions are based on different measurement methods. If you follow my trimming instructions exactly, you will get my measurements.

      LG Heiko

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