Beneteau 25 Tuning Guide
Rig set-up
The North Sails TB-2 main and LM-4 jib are "state of the art" sails which have done well in many regattas.The main is quite powerfull and needs some prebend in rig set-up. The pre-bend should be set close to 50mm. The best way to check this is tie the main halyard at the gooseneck, pull the halyard very tight and check the distance between the halyard and the back of the mast. The uppershrouds must be very tight and as tight as possible in hvy. air conditions in order to tension the headstay. In lighter air you should slacken the upper shrouds at least 3 x 360 degree turns in order to get some headstay sag to make the front of the LM-4 jib as full as possible. In heavy air you should use the GH-2 jib (which is a bit smaller and flatter as the LM-4 and better in a breeze). The lowershrouds should be adjusted according to the pre-bend as described before. The mast should not bend more as 130-150mm. Check the intermediates (shroud from the lower spreader to the upper spreader) in all settings (tight and less tight) so the mast is straight up untill the hounds (this is where the forestay comes into the mast). Some sideways mastbend must be accepted, because this cannot be influenced by any adjustment.
Tips & Tricks
Put a device on the bow of the boat which prevents the spinnakersheet from falling in the water. You will drive over the spinnakersheet, and that's slow, and difficult to get back on the boat as long as the boat moves forward. Put a sailbatten on the top of the mast to prevent the mainsail leech from hooking behing the backstay. This is nasty, especially gybing in light air, which must be done frequently.
Mainsail Trim
Never pull the backstay. Sheeting the mainsheet does all you need to flatten the mainsail sufficiently. Adjust the foot of the sail (along the boom) enough the reduce the helm (pressure). Never pull the mainsail very flat on the boom, specially not when the waves are choppy and short. The boat needs enough drive to power through the waves, since it is very short and starts "hobby-horsing" i.e. bow up&down quite easy. Traveller should be played all the time in every gust, so the boat is feathered and not heeling, because that is really slow. If the traveller is not enough, ease the mainsheet a bit to keep the boat on its feet. The cunningham should be used with care, never pull too much, it moves the draft (deepest point of the main) too far forward. Pull enough to remove some wrinkles, but not all wrinkles. Try to accelerate, and not to heel. The boats are very sensitive, and must be sailed with a lot of concentration and dedication, specially from the mainsail trimmer. Keep the crew on the rail all the time.
Jib Trim
First thing you have to do is make marks at the upper spreader. Make a mark every 5cms from the outboard end going towards the mast. The last mark should be at 25cms. Never sheet the sail harder as to this last (most inboard) mark, so this mark should be a bit fatter or another colour, so it's easy to see through the window in the main. The lead (trackposition of the jib) should be very close to the most forward end of this track. This makes the jib look a bit crazy, but that's fast. The barberhauler must be pulled inboard all the time. In smooth water (no waves) up to 10cms. In waves no more as 5cms. Look at your boatspeed, and work the jib barberhauler, just as you must do with the mainsail traveller. The best way to do this is lead the barberhauler across the boat. This means the barberhauler from starboard is led to the port cleat, and vice versa. That way you can adjust the barberhauler without leaving the rail, remember, the crew must hike hard.
Crew Weight & Position
Move forward with three crew in light air, at least around the mast. This must be done with less boatspeed as 3 knots. Above 3 knots move backwards, but not a lot. Above 6 knots the crew can be in "normal" position.
Length of Headstay
In light air you should use the longest headstay possible in order to create more weather helm. Remember to adjust the shrouds as described above. In heavy air go 1 hole shorter on the adjuster, and again, adjust the shrouds.
Wind angles downwind (Spinnaker)
The B'25 is very sensitive to apparent windspeed. Smaller wind angles make the boat go a lot faster. My experience is to keep the windangles as small as 95 to 100 degrees in light air. Look at the boatspeed, and check the windspeed at all times. More wind, steer deeper (more downwind), less wind, steer higher (closer to the wind). Keep concentrated downwind, you can gain a lot of distance, but you can also loose a lot of distance. Check the truewind angle. If neccesary gybe as soon as the wind shifts in your favour i.e. the app. windangle is getting greater. Talk with the crew trimming the spinnaker, let him decide if there is "pressure" or "less pressure". He feels most, having the sheet in his hands. Running in more breeze "work" the boat. Point the bow of the boat down the waves at all possible times and "rock" the boat through the ride of the wave.
For a more detailed tuning guide for the Beneteau 25; please click here.