Kicker and Cunningham - Yachts and Yachting Online Forum (2023)

I've heard so many conflicting explanations of what these two controls do, and how to use them best, that I'm simply confused as to how they work.

1) What do they do to sail shape?

2) What should be done with them upwind in light, normal and strong winds?

3) What about downwind on an assymetric (i.e. 29er) across the wind range?

4) What about downwind in a boat without a spinnaker?

5) If I want to depower, what do I do? I've heard lots about how kicker rakes the mast and depowers, but also how it powers up and accelerates.

The reason you've heard different stories is because, oddly enough, they have different effects in different boats. In most modern fully battened boats you use downhaul (~=cunningham) to bend the mast and flatten the sail and kicker to control twist, but its so boat specific that your very best bet is to seek class tuning guides or better yet training days.

For the 600 the guide on the RD website is a good starting point

RS200 and returning to a Musto, ex 300

(Video) The Cunningham, the Halyard and Luff tension

Hi Jaws

i see you have a 29er so lets start with that....

this is gunna be disjointed and messy so here goes. And probably as bit basic for you but I may as well put it down as its going to help somebody

To sail a 29er fast is easy if you follow 3 golden rules (upwind)

Rule 1 the boat must be flat, I mean dead flat, if a competitors boat is flatter than yours assuming they have the other 2 rules working for them they WILL go faster than you.

Rule 2 you must have the boat set up to 100 power or close as you can to it, in 6 kts 100 percent power is not achievable as there just isnÂ’t enough wind but you get as close as you can by not losing any of the winds power needlessly i.e. poor boat set up ( too much kicker not enough main tension) if your sailing around in 17kts and your not hiking as hard as you can and trapezing as hard as you can you are not at 100% power, your giving power away and power = speed

Rule 3 you need your main sail on the center line as much as possible, if it is eased you choke the jib slot and go slow

Ok so letÂ’s break it down

(Video) Sailing : Outhaul Adjustment and Function

The leach of your main sail generates the power and height, if the leach is open you lose power (it spills out of the sail) if it is closed you have more power and height, due to the leach return.

The kicker controls your leach so..... pull more kicker = more power and more height! Simple job doneÂ…..Unfortunately not. The 29er has no lowers, therefore there is nothing counter acting the horizontal component of the kicker,

Pull your kicker on yes your leach will tighten good for power and height but

your mast will bend (mast curve will come closer to matching the luff curve) thefore the sail will become flatter and you will loose power = Bad

so in one hand the kicker powers you up but it also depowers you, not ideal if it 8kts and your not sailing at 100% power (remember you donÂ’t want to give away any of that lovely go faster power do you!)

In a boat where you have no way of controlling the lower bend your secret weapon is dun dun darr Â…. main sheet tension. The main sheet pulls directly down on the leach with very little horizontal pussh in to the mast, Winner! So in conditions until we are ready to give power away thatÂ’s when your at 100% power hiking and traping hard and dead flat and the next gust will require a big main sale ease aprox 12-13 kts depending on size.

So how this works

Drift no kicker no Cunningham, mainsheet tension enough to keep the main sail on the centre line but not close the leach itÂ’s a bonus if the main leach tale tale can fly

Light wind- no kicker no cunningham, boat dead flat THIS IS NOT ACHIVED BY EASING THE MAIN SAIL BUT BY MOVING YOU WEIGHT IN AND OUT main sheet tension used to control the leach, crew look to fly the tale tale aprox 75 percent of the time, if its flying to much crank on the main, flying to little ease the main. Simples, but this takes a fair level of concentration from the crew.

6-knts ish to 100% power ie flat wiring hiking hard (prob 12-14kts) . no cunno at all, main sheet tension on hard im talking proper hard crush your hand hard, trapeze wire might even go a little slack hard, in the lighter stuff the crew will still watch the leach to make sure he/she isnÂ’t cranking on that main too hard, looking to fly the top tale tale 75 percent of the time. Now this is the breeze where a little puff may require a main sale ease to for fill the most important rule number 1 keeping that sucka flat, NOW REMEMBER THAT MAIN SHOULD NOT BE EASED FOR MORE THAN A COUPLE OF SECONDS THROWNG GO FASTER POWER AWAY UNLESS YOU ARE TRAPEZING HARD AND HIKING HARD

now you donÂ’t want to instantly lose all the power and height you have generated with main sheet tension so you set the kicker to bite and hold when you ease the main (ie when your sailing along there is little to no load in the kicker but if you ease the main the kicker holds the boom so it doesnÂ’t sky. (remember in this mode if you get a lull and the main has to be eased to fly the top tale tale the kicker needs to come of ASAP to avoid stalling out the main. How hard do you pull the mane sail,,,,,, very hard it should certainly hurt the crews hands, remember if you need to pull kicker to control that leach so you can hold height your going to lose power = less speed. Top crews arenÂ’t hard with big guns for no reason.

100% power and onwards Flat wiring hiking hard (this wind speed varies on your weight) ok this is where your mode of sailing changes and we are talking about planning up wind, you are at 100 % power and your starting to ease the main sheet therefore your kicker is taking the load your crews hands were taking earlier, this mode on wards you gradually pull on more and more kicker to depower, why do you depower to keep to golden rule 3 that’s why! your leach will harden up as hou pull in kicker more but as explained earlier your sail will become flatter as the wind builds you use this control to balance the power from the sail looking to keep the main on the centreline to about a foot or two of the centreline…….. if you start easing beyond this “range” pull some kicker on if the wind drops and the helm stops hiking or the crew needs to come up on the wire ease the kicker pronto, pull the sail in, and be ready to slip back in to crank the sheet hard mode if you get any sustained lulls at or below 100% power.

(Video) Sailing: Backstay adjustment

18 kts overpowered struggling to keep flat and main on the centreline. ok so your kicker has been crept on as it has got windier to keep the power under control so that you can keep the sail near the centre line the boat flat and ripping forward now your starting to see that big bad crease coming from the spreaders going to the end of the boom. This is called the luff starvation crease and is telling you that you have bent the mast to a shape beyond that of the luff curve in the main sail and you have made the sail flatter than a flat thingÂ… PULL THE KICKER NO MORE.

This is where our friend the cunningham comes in to play, this control is not used at all until our chum the luff starvation crease appears, what the cunning ham does is open the 4th corner of the sale ie your square head top sail or upper leach. As the breeze increases and you feel the boom is coming of the centre line and you have done all the de-powering you can with the kicker its time to pull the cunno on to depower the sail so you can get it on the centre line and ripping againÂ… in sustained lulls you must let your cunno off immediately so that your not sailing around in 18kts with 90% power with your knees bent going slow.

So you get to the point where you canÂ’t pull the cunno on much more youÂ’ll just have to depower the old fashioned way Â….. and pull your centreboard up a few cm to a 15cm when its nuking! (this tip is golden most ppl forget to do it when it gets windy and it makes a huge difference in any class)

If you can do the following better than anyone else; keep your main sail near the centreline, the boat the flattest and hiking and trapezing hard as soon as you can youÂ’ll be the fastest boat out there.

This is all simplified and done in a rush to help you or somebody else out.

My back up to this is a 7th and 2nd at 29er world champs back in the day and a few years coaching the youth squads.

Marks Geotechnical, for all your Geotechnical and Environmental construction needs.
Need a phase one desk study for planning permission?<

Thanks Marksey, I've generally been using the cunningham at the same time as the kicker on the 29er, which might explain why I go slower upwind than I'd like.

Does the same thinking apply downwind, pulling kicker on until it can do no more, then using cunningham?

(Video) Boat Balance: How To Use Sail Camber (Kicker & Outhaul) To Maintain It

Edited by Jaws - 13Sep11 at 6:51pm

glad I could help,

ok down wind you want no cunningham, in fact you want to let it off before you bare away, when you pop the kite it theory you could tear the mainsail as the bend is taken out of the mast (being pulled forward by the kite) I have never seen this done but you never know! Downwind the power disappears from the main sail in to the kite, the main is generally trimmed to give an efficient slot for the kite. You want all the power you can get in the main sail down wind so get that cunno off!

As you bear away you need to lose the power in the main sail to allow the boat to turn away from the wind so ease your kicker before you initiate the turn.

Since there is no load in the main sail their whilst the kite is up, there is also no load in the leach so your leach will be way to hard if the kicker hasnÂ’t been eased, you need enough kicker not to let the leach bellow open or the boom sky,but not so much its hooked closed, it certainly shouldnÂ’t be pulled hard, in the lighter stuff keep an eye on the top tale tale if its not flying ease it a bit more kicker.

In the windy stuff the kicker is not set for speed so much, but its set for the gybes. If the leach is too open (not enough kicker) will be two open and the boom will resist crossing the boat , buy the time it does cross you will have turned to close to the wind it will snap across with a wallop and capsize you. Too much kicker it will cross easier but the main sail may start to load up prematurely after the gybe causing a broach out. But gybing is a whole other post altogether.

(Video) Balanced Sails

Marksey, This is really useful info. So if you are feeling generous then your thoughts on gybing would be appreciated.


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