North Sails RESOURCES
Starling Tuning Guide
- Last Updated: August 23, 2017
- Tuning Guide (PDF)
The object of the Starling class is for all sails and masts to be identical.
We pride ourselves on our ability to reproduce sails identically, so please feel free to contact us if you feel your sail isn’t the same as other sails. This is important as it allows us to improve our methods, and ensures all sails out on the water are the same. If for any reason your sail is outside the tolerances, then we will replace it.
The luff of the sail is 4040mm long.
If you are fitting a fixed height gooseneck, then allow 4025mm from the top of the boom to the top of the sail.
The foot is 2115mm long.
Allow for the outhaul to pull the sail out to a maximum 2125mm from the aft face of the mast.
The leech is 4370mm.
Always roll your sail and keep it in its bag when not in use. Ideally remove the
battens after use. If you don’t want to do this, then release the battens from the pocket elastic and roll the sail parallel to the pockets. If you are rolling onto a tube, tie the clew first and roll the sail a couple of turns before attaching the tack. This will allow you to roll the sail parallel to the batten pockets on the tube. Wash the salt from the sail every 3-6 weeks depending on how often it gets wet. Do this on a light day by hosing the sail while rigged, and leaving to dry.
The tack should be set on one of the holes on a standard gooseneck fitting (about 25mm from the mast) for. Choose the hole which makes the tack area of the sail setup smooth.
There are no rules requiring black bands. To take maximum advantage of this, make sure your sail is as high as possible up the mast. Check that your mast is the maximum length allowed under the rules (4480 from base to tip.) If you have a fixed gooseneck, then you will want the sail to be at the top in heavy airs. You will need 2-3 talurits on the halyard strop so you can adjust the luff tension to make it looser for lighter winds.
Make sure that the boom is long enough so you can get maximum tension on the outhaul when the wind increases. Check that the sail doesn’t extend beyond the end of the track on the boom or it will damage the sail.
Your sail comes with a standard set of battens specially designed for the Starling.
Smaller skippers will find a benefit from changing to a heavier #2 batten as the wind increases.
The basic shape of the sail features a very straight (or flat ) exit, so there shouldn’t be any need to change the lower battens from one condition to the next.
Remember – the stiff end of the batten is the back. Bendy end forward!!!
We suggest 4:1 purchase inside the boom, so you can make small repeatable adjustments. Make sure you have a system of marks so you can repeat your fast settings from upwind to downwind- or when the breeze changes. Use a shock cord system inside or outside the boom to help the system release.
Don’t ease the foot too much. If you are getting vertical wrinkles off the boom, then you have gone too far.
The Starling sail has the ability to be set up full, but then to flatten really well as the wind increases. Experiment with various settings so you know what is fast for your weight in each condition.
Following is a formula for working out the correct mast rake for your hull.
Because there is a variation in the hulls, there is no correct rake to suit all boats. There is a correct rake for your individual boat and you should have a record of this and of the rakes you try. Another way to find a starting rake is to level your hull alongside a top boat. Then sight
the masts and set your mast up to the same angle. Measure this from a mark permanently etched on your mast to a mark on the stern. This is your rake.
The following system will give you a good all round rake. You should feel free to use this as a starting point and experiment slightly forward and aft of this point.
Measure up 3050mm from the deck and mark the back of the mast – this is the new rake measuring point.
Measure from the 3050mm position to the intersection of the deck and transom
A good starting mast rake is 3640mm.
From this position, individual skippers will need to adjust the mast rake to suit their body weight and sailing style. If more speed is needed downwind, rake the mast forward, and if more pointing ability is required, rake the mast further aft
It is a good idea to glance up at your sail occasionally especially when you are going fast- (or really slow) to see what your rig looks like and therefore be able to eventually memorise these shapes and settings.
Look carefully at the top batten. Try and guage how open the top batten is and use this as a reference to compare with
previous settings. This tells you how much mainsheet and vang you should be using.
Tight v’s loose. I prefer a firm rig. The tension should be so that by pulling forward on the mast you can just do up a shackle on the forestay. Any tighter
than this is unnecessary. My reasoning is purely practical.
There are pro’s and con’s for the 2 extremes. If you have a loose rig, it will give you more optimal fore and aft rake upwind and downwind, whereas a tight rig can’t move. However a loose rig also means it falls away sideways which isn’t desirable. I think that this is why the 2 styles ultimately perform equally. Of course what the top skipper is using will always appear fastest!!- but look carefully at what else he/she is doing.
My practical reasoning is simple. A loose rig is more susceptible to wear and therefore failure. The movement also makes it more prone to shackles etc working their way loose.
If you are a methodical type of person and check your gear often, then by all means go for a loose rig if you believe it to be the way to go.
If you have a rotating rig, you may need to have it a little looser to help it rotate more easily. Try a 1-2mm thick teflon washer under the mast.
All masts must be from the same F4 section from Fosters. There is a 150mm range between the maximum and minimum heights for the stays. We suggest having the forestay close to min (2800) and the sidestays close to max (2950).
If you have a rotating mast, then we recommend an inner forestay at 900mm. This should be set very loose so that when the boom is right out there is still about 20mm slack in the stay.
Due to the nature of the mast construction, there will be variations in the stiffness of the masts. Beware of this as it can be the reason for consistently poor performance in certain conditions. Avoid masts which are too stiff.
If you are over 60kg you will start needing a stiffener in you mast. If you are careful you can wait until you are over 65kg- however you run the risk of breaking rigs downwind.
Your vang is there to control leech tension once you run out of width on your traveller. If the breeze is light and you aren’t having to ease the main in gusts, then you don’t need any vang. In these conditions you should have it just eased, so that it isn’t taking any load.
However, you don’t really want it too loose or else it will take too long to pull on should the breeze increase.
In the lighter breezes you are quite often sheeting quite loosely, so make sure there is no tension on the vang.
As soon as you find yourself easing the main in the gusts, you should have vang on. This should mean that as you ease the main in the gust, the boom moves outwards only- not upwards.
Remember vang bends the mast and flattens the sail a lot, so if you are hunting for power, make sure you don’t have too much vang on.
Be sure your rig and fittings are strong enough, so that you aren’t afraid to use a lot of vang when the wind increases.
Reaching is similar in trim to upwind. In the light you will have to be careful not to close the leech too much, however as the breeze increases, you will need to slowly increase the amount of vang to keep the leech under control and keep powered up. Again too much vang will bend the mast too much and lose power.
Downwind you will need less tension than you have had upwind or on the reach.
Ease vang as you go around the mark.
If you can imagine looking up from the boom, the ‘twist’ or amount the leech opens, should be nearly the same on all points of sail, in all conditions.
For this reason it is a good idea to get used to looking up at how open the top batten is and try to adjust the vang to keep it looking the same as the wind changes.
Cunningham does two things. It moves the shape forward in the sail, and then as you use more, it bends the the mast and opens the leech in the head.
Cunningham is the last control you should be using to depower. You will already have a good amount of vang and full outhaul before you use the cunningham. The more you get overpowered, the harder you pull on the cunningham.
Your centreboard is another very important control to how the boat sails. The rake and positioning of the centreboard changes the balance of the
boat and makes it easier or harder to sail. Basically the further forward and further down the board is, the more power
you will have. You may even try raking it forward a little in the light. As the breeze increases you will begin getting overpowered and the helm will start getting a little heavier. A heavy helm
is slow, as you are holding the rudder against the water flow and creating drag just like a big brake. Therefore as it starts getting heavier, it is time to start moving the board. Firstly do this by raking the board. Leave the top at the front of the case, and let the bottom move as far aft as possible. You will probably find it faster if you begin doing this a little earlier in choppy conditions.
If you are still overpowered, you can now start lifting the board. Don’t be afraid to sail around with up to 150mm of board up if it is windy.
This will allow the boat to sail flatter, especially through the gusts, and to move faster through the water. Be aware to begin putting it down again if it lightens, or else you will find yourself not pointing.
The rudder is very important. You sail the boat by feel. The position and rake of the rudder will effect this feel. As a
rough rule the rudder should be set up so the leading edge is square to the water.
However it is even better to fine tune it from here by trying it a little back or
forward from this position. Changing the tip postion by 10mm increments is about right. Once you are happy, then fix it in place with some sort of system which won’t allow it to move around.
The rudder ‘feel’ should be light in all conditions.
Make sure there is no slop in the rudder system. There is potential for wear especially in the gudgeons. If this is the case then replace them with a good positive system.
Even the best skippers need calibration marks. These enable you to keep the best speed from week to week, and to keep learning how small changes effect your performances.
Highest priority is the Outhaul, the cunningham and the vang. I would also recommend some marks on the
mainsheet. Marks on ropes can be done with markers, or better still, by sewing contrasting thread into the lines.
Good luck, and please feel free to make comments and contributions to this guide.