Jib and main trim

[Don Guillette]

I was glancing again at the "post a picture" thread and one of the things I noticed was the jib trim in comparision to the main trim. For the most part, the mains looked pretty good but the jibs did not look so good. If you have a mast head rig (jib is the engine) the trim of the jib must be set first. That is the opposite of what most masthead rig sailors do. They set the main first and the jib becomes an afterthought. In addition, they do nothing with the fairleads. The correct way to trim your sails is to set the jib first and then set the main to MIRROR the jib. Take a look at Alan's correct main and jib trim and you'll see what I'm talking about. When you do it the way I'm suggesting you'll be surprised how much power and performance your boat will have.Merry Xmas to all and a happy New year!!

 

[Ross]

Don, I have no doubt that your observations

are spot on. But I wonder, for a cruising sailboat under reasonable trim vs optimim trim how much difference would you record in a noon to noon run? I am NOT gonna take you to task about your answer and I will stomp all over anyone who does.

 

[Rick D]

From Experience

...I'd say the difference in fine vs. not-so-fine trim is on the order of 10-20 percent. So, for an overnight trip, it's worth a couple of hours easy. And, for a 1200 nm trip, an easy day. What I do think is just as important, the boat responds better, is (probably) better balanced, and you get to play some mental games to break up the boredom by pulling strings and tweaking stuff. ;D I'll be interested in other's responses and estimates. Rick D.

 

[Ross]

This is the third try.

Rick, Cool.

 

[Alan]

Ross

The question you raise is very valid. Some skippers on cruising sailboats are not really interested in the extra performance that can be gotten from proper sail trim. It's not a matter of 'racing' or 'cruising' so much as the mind set of the skipper. There is only one 'proper trim' which has nothing whatever to do with the kind of boat you are sailing.When I am racing my boat, proper trim is important for the obvious reason that you go faster. When I am cruising, I cannot ignore the fact that the leach of the genoa is fluttering or that the upper outboard telltales are stalled. It would be like driving my car with one foot on the accelerator and the other on the brake pedal. After you master the 'black art' of sail trim, there is no going back to not doing it. I find myself not only trimming my sails but also always looking at the trim on all the other boats around me. I guess it's just my anal need to do the best I can. Rick's estimate of the amount of gain or loss is, in my estimation, spot on. The 10 to 20 percent range would be a valid number under normal circumstances. In ultra light or very heavy wind those percents will certainly increase. Merry Christmas skippers

 

[Alan]

Tim

Being you asked, I'd like to comment.The genoa is not drawing at all at the top of the sail. I can't read the telltales but I'm quite sure they are stalled. This could be improved by moving the genoa car forward. Even better would be to switch to outboard sheeting. Attaching a changing sheet to a snatch block on the toerail would allow you to close the top of the sail and still move the angle of attack toward the wind.The main is reefed but the outhaul on the clew is at least a couple of feet too long. As a result, the top of the main is stalled. If you removed the reef, you could lower the traveler and increase mainsheet and/or vang to flatten out the main a bit. This would decrease heel and increase boat speed and comfort and decrease the weather helm you are experiencing.I would estimate you would gain 1.5 knots of boat speed as a result.Just my 2 cents worth.

 

[Ross]

I think that the sail plan on Bietzpadlin

must be unusual. The hoist on the mainsail is only 28 feet and the foot is 13feet. The pictures that I see would have the ratios more like 3-3.5:1 For the height and the foot. My jib is also small compared to other boats around me. It seems to me to be over canvased in anything over 12-15 knots and needs a reef.

 

[newsailor06]

I am still just learnin'

Even though the Admiral and I have been around boats a lot, we didn't begin sailing on our own until this spring. We did take the basic keelboat course from ASA so that we would feel comfortable at least. The Admiral is still working on that part. However, after eight months at it, I find myself constantly trying different things. Moving the traveler, loosening/tightening the outhaul, loosening/tightening the boom vang, same with the sheets on the genoa, and loosening/tightening the main sheets. I try also to read about sail trim so I can learn more. Sailing is much more than raising the sails and heading out...and I love every minute of it!

 

[Warren Milberg]

For Ross

Sounds like you have a classic low aspect ratio rig with a relatively big main and small headsail. What type of boat do you have? I'm guessing you have more sq ft in your main than I do in my H28.5 (31.75 x 10.86). As to reefing, I normally have to shorten sail when I'm sailing with my 150 genoa when the wind gets up to or above 14kts or white caps are just forming. At that point, I have a lot of weather helm and heeling. When I use my 120, I can go up to 16-18 kts before reefing something (ususally the headsail as its easier with a furler when you are alone). So it would seem you are right in the ball park re when to shorten sail, IMHO. Try posting a pic of your boat by holding down the "Control" key while uploading. That works for me.

 

[Ross]

Posted a picture of the boat at dock

don't have one while under way. The boat is 1968 Islander. She is a bit tender at first but stiffens up at about 15 degrees, (just about the time Nancy starts to squeak.) Don't have roller furling but I did sew a reef in my working jib.

 

[Don Guillette]

Reasonable vs Optimum trim

Ross: Like old Bill Clinton said "it depends on what the meaning of is is" or how close reasonable is to optimum. Lets say the reasonable trim is what I normally see sailing in Long Beach or what I see on boats I go aboard for a sail trim lesson. In the second case, I generally ask them to set their sails as they normally would so I have some basis from which to start. In these cases, I can easily get them at least 1 more knot of speed. In the first example, with the folks I see sailing around the harbor I could probably get a knot and a half or more increase. The reason for that difference is the skippers who contact me for advise are already partly there from a sail trim standpoint and they just need a little help getting over the top.That second group are cruisers and racers who want to get 100% from their boats are a small minority and probably comprise about 25% of the sailors worldwide. I'm in that group and those are the folks I sell 95% of my sail trim products to. The next group are the top 25% and are in the expert catagory. They don't need any help as they are already there. The majority of sailors fall into the catagory between 25% to 75%. I would really like to tap into that group but a friend of mine from San Diego said it best when he told me a lot of these guys "don't know what they don't know". They just hoist the main and roll out the jib. Tomorrow or the next day I'm going to do a short fun piece on what I call "grin and giggle" sail trim.Hope all you guys have a nice Xmas day. Temp should be in the 70's here in Tucson. The golf courses where we live are offering golf at $15 for 18 holes with a cart (I have my own cart)but it is still a good deal. I may pay 9 anyway for that price.

 

[Bob7291]

More input, Tim

I'll give it a try, as well...You have a reef in the main, which tells me the wind is probably relatively strong and the boat was somewhat overpowered when beating. Now that it is on a reach, heeling is not so pronounced and not much of a problem. The foot of the genoa is quite flat, while the sail is twisted off quite a bit up high - that might have been necessary when beating, but now it is only bleeding off power and isn't the most efficient setting for reaching. If you move the genoa lead forward and then sheet accordingly, the sail shape would be more efficient for a reach - less twist up high, more shape down low. As for the main, I don't see any tell-tales on the leech. Until you have them to indicate what the air is doing as it exits the main, you are only guessing or else you are really, really good. Most folks who don't have tell-tales tend to sheet their mains too tight - the sail seems to have a nice curve and they figure that is the optimum. But as you come off sailing hard on the wind and are still trying to gets lots of flow attached to the lee side of the sail, the sail generally can be eased more than seems optimum - and the tell-tales communicate how much farther it can be eased. Once you are used to relying on tell-tails to set sail trim, going out without them is like flying a plane with no instruments. Your sails have nice matching leech curves, and for that reason appear to be properly set, but I'll bet you could improve on the setup some.

 

[Don Guillette]

Input

Bob: I like the way you answered Tim's question. You indicated what you thought should be corrected and MOST IMPORTANTLY you advised him how to make the adjustment. Alan, Stu, Joe from Mission Bay and some others do the same. Why that is great is that many of the forum listers are beginners to intermediate and to tell them the main or jib is twisted or the draft depth is wrong does nothing for them. You may as well tell them the sky is blue.On the other hand, some of our forum listers recognize there is something wrong with their sails or the sails of those around them but they don't have the foggiest notion as to how to correct the situation. Sail trim is so simple when it is presented in simple English with a logical common sense and step by step approach. Too many times the explanation we get from our sailing friends and dock neighbors is so screwed up that you walk away shaking your head.If any of you don't believe me just ask your dock neighbor to explain the difference between draft positin and twist plus what controls for the main and jib are used to adjust both items and see the answers you get!!How many of you could explain the difference. If your a regular forum lister the explanation would be simple and CORRECT.

 

[Alan]

Welcome to...

...the sailing world. I would highly recommend you buy Don's book on Sail Trim. It is very well written and will teach you the beginnings of sail trim.

 

[G. Bean, s/v Freya]

Photos

Yikes! And I thought that the purpose of those photos was a little “ego stroking.” Now, for a little ego bashing. Can you guys (especially Alan and Don) look at Freya (message #36) and tell me what you think?

 

[oldiesrocker]

Are All Masthead rigs equal?

Don, My boat is a masthead rig(V21) that is mostly day sailing with occasional weekend jaunts. During the summer I tried to experiment with only the head sail and found that despite the jib(furling) being, I believe, for a smaller boat, the boat would continually fall off into a broad reach without the main up. I had to build up quite a bit of speed to even attempt turning through the wind. Keel in full down position, jib sheets inside the shrouds, myself and the admiral seated as far forward in the cockpit as possible. A situation like this has always kept me from setting the jib first. Having an ancient hank-on jib on my older O'day knock-off simply made it inconvenient to deal with the jib with the main down. Any suggestions?

 

[Don Guillette]

Freya

G Bean: I think your main and jib trim are excellent. I can't tell from the picture but it looked like there was a lot of belly in the jib but I think it is a shadow or the angle the picture is taken at. The heel is just about right. I've mentioned before that while racing I check the set of the sails of the boats in front of me to determine if it is only a matter of time before we over take them or if it is going to be a long day - if I was following Freya it would be a long day!!

 

[Don Guillette]

Masthead Rig

Oldiesrocker: Here's how it works with a masthead rig - if you sailed with only the main the boat wants to head up. If you sail with the jib only, the boat wants to fall off. The combination of both sails working together is what causes the boat to go straight.The first sail you raise on a masthead rig s the main. Conversely it is also the last sail you drop. So, the proceedure is to raise the main and then roll out the jib. Next you want to trim the jib using your telltales and then set the main to mirror the jib using the mainsail telltales.I know lots of guys prefer to sail with the jib only and I guess it boils down to what they are trying to accomplish. If they are trying to depower the boat and make the sailing experience more comfotable then they are using the wrong sail. On a masthead rig the jib is the engine. If I'm going to sail with only one sail I prefer to sail with the main only because it is easier for me to control.I've only had a couple of opportunties to ask masthead rig "jib only" sailors why they are draining the swamp or sailing that way and the answer was they felt the jib is less powerful than the main.

 

[Moody Buccaneer]

It's the old 80% rule

Hoist it, set it, and cleat it will get you close. About 80% of pontential.If you pay very close attention to a "steady" breeze you will find it is not steady at all. Set the leech of the genny 1" off the spreader after you tack and cleat it. Sail for 2 minutes as the boat settles in to the new tack and look to see if it is still 1" off the spreader, it probably won't be.Have someone else drive and see how many adjustments it takes over 10 minutes to keep the leech 1" off the spreader.Low aspect ratio sails are more forgiving than high aspect ratio sails. The 150 is easier to trim than the blade. Big mains with long booms and short luffs are also more forgiving, not to mention much better when not sailing hard on the wind than the tall skinny mains found on many boats. Mains like Ross's are wonderful reaching sails and make for hours of pleasant sailing.Every adjustment that is not made means sailing at less than optimum settings. Over a span of hours this can easily cost 20% of distance sailed. 1 knot is 20% of 5 knots.24 hours at 6 knots is 144 miles, at 5 knots it is 120 miles. It is the difference between 19 days at sea and 23 days at sea when crossing the Atlantic.Our unfortunate solo circumnavigator was making only 80 miles a day. His boat should be able to make 6 knots easily. 80 miles instead of 144 is 64 miles wasted, there are no 2.6 knot adverse currents in the waters he sailed. There is no doubt in my mind that poor sail trim is the cause of his 3.3 knot average.My wife claims I like to fuss, all I'm doing is making adjustments as often as needed to keep the sails trimmed properly.

 

[Don Guillette]

Great Picture

G Bean: What a wonderful picture with the bridge in the background. It belongs in an ad in a sailing magazine!! Who took the picture??After I got over the joy of looking at the picture, my first thought was that the jib might be to tight but I'm not sure. One of the problems that happen when you sheet in too much is the "cup" that forms on the jib does not allow the wind to exhaust. In other words, the wind has to bend in toward the boat and it almost acts like a brake but if all your jib telltails are flowing straight out your OK. You have to experiment to be sure.I've raced in the Catalina30 National Regatta on San Fran Bay and the jib trimmers job is a lot of work - that's the main reason I never take that job.A couple of years ago I was lucky to be able to sail an America Cup boat in St Martens. In the modified race we came in second (there are only 2 boats so that means we lost) by a hair and I feel it had to do with the way the jib was "cupped". I have a picture of myself sailing the boat and everytime I look at the picture I think if that jib had a better airfoil shape we would have won that race. I wanted to say something to the skipper and trimmer but what do I know so I kept my mouth shut. I don't see any wrinkles on the jib. Do you have a adjustable fairlead system such as made by Garhauer? Possabbly a slight adjustment on the fairlead would eliminate them. It is not a good idea to rapidly sheet in the jib after coming through the tack. Lots of folks do that but slow and steady is the idea as it allows the jib to power up. I don't mean the trimmer can go to sleep but he does not have to maddly trim in.