140% alone gives better performance. why?..

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Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
over the weekend we had some steady wind, 10-13kts in the morning and 12-17kts in the afternoon. we also had a few sustained gusts of 20-22kts....

after we weighed anchor, we pulled the 140 gonoa up just to see how it sails by itself before we changed to the working jib...
what I discovered surprised me....

the boat is loaded with gear and sits trim in the water but with only about 1" of the water line visable. with the mainsail only the boat is a slug. when its rigged with the jib and the main it sails decent and points decent, but in anything over 12kts I have to reef the main and fly the working jib. it will run close hauled at 4.3-4.7kts
any more sail up and she lays over and slogs thru the water quite a bit slower...

so when I tried the 140 by itself, I found the boat stands up well in winds up to about 16kts and will run at a steady 6.5 to 7kts... we did see a couple 10-15 second bursts to 7.8kts in the higher gusts... this is running close hauled and actually being able to point higher than when Im running the main and the jib in combination.
when we were not tight to the wind and were running off a bit, the higher gusts would lay us over and the boat would slow down to about 5.3kts, but what was most noticable was, as it layed over that far I was expecting a round up, but the tiller seemed almost perfectly balanced. it was responsive left and right and without pressure.
at about 24degrees of heel, (according to the meter on my contest compass) my rail is at the waterline, and it seemed to be sailing fine that way on the genoa alone in 20kts of wind.
but it does sail a lot faster when she is standing up and not heeling over.

so my questions are....
..why should i hoist the main when it sails so well on the genoa alone?
..do you think i am putting too much strain on the rigging running that much jib in that much sustained wind?

now that ive learned it will go fast and sail well on the jib alone, I need to find out why its so difficult to sail on the main by itself. it either wants to round up or fall off, depending on the strength of the wind, regardless of how I manage the rudder. could too much bend in the mast cause this?.... my rear stay was a bit tight and i havent tried the main alone since i slacked it...

even though the sail has had very little use and is in great condition, but im sure it is probably a generic cut. it is the original sail that came with the boat.
 
Sep 25, 2008
961
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
I'll bet your keel is locked in place too. When it's locked, your center of resistance is forward, which is why the headsail alone was working ok. When just the main is up, you need to move the resistance back ( dare I say raise the keel) to balance the sail. Go in small steps, try 5 cranks up, see how that works, then 10. I usually sail with my keel about 5 cranks up from where the lockdown holes all align (about 37 cranks down from full up). 10 to 20 degrees of heel is the sweet spot for these boats.
 
Nov 8, 2010
11,386
Beneteau First 36.7 & 260 Minneapolis MN & Bayfield WI
How old is your mainsail? Is it getting bagged?

In any case I'm guessing you are sailing with too much camber in your main. Generating too much lift and overpowering you. Can you adjust that?

As the breeze picks your should ideally flatten your main with outhaul and backstay tension. Adding backstay bends the mast and flattens the middle of the sail. Outhaul flattens the bottom. Then Cunningham on to move the draft forward. The flat sail generates much less lift (and drag) and keeps it from becoming over-powered. It will not heel the boat as much, be faster and help you point higher.

I'm guessing 90% of all sailors control their main with sheet alone.

If you use your traveler youre in the top 5%

But total control requires use of the fine tunes.

PS- sailing upwind in a breeze with just headsail is one of two hardest loads you can subject your rig to. The other is sailing with just a reefed main.
 

kenn

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Apr 18, 2009
1,271
CL Sandpiper 565 Toronto
Another place to look - is the main bagged out, or loose? Try tightening the luff and the outhaul to move the main's draft forward. Also I often see people pulling in the mainsheet too much, which means more heeling than forward drive, and it increases weather helm, which means more rudder to correct course ( = drag). Try easing the main. Telltales on the main will help with the tuning.

When we're going off the wind and not in a hurry, I regularly drop the main and just run on the jib or genoa. More relaxed, less effort to stay on course, and no threat of accidental jibes.
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
the keel is locked down... i like to keep it down and pinned with the cable loose so it doesnt hum:D

I dont know what "camber" refers to in sail terms.

I thought that tightening the backstay to bend the mast was more of a technique for running broad or away from the wind, and that the backstay should be loosened when sailing close hauled....

I dont use a traveler... I have the original end boom sheeting, and use a vang to pull the boom down.... and again, I have always thought the vang is more of a control for downwind sailing that it is for sailing upwind... i always have it loose except when on a beam reach or with the wind behind me.

I have thought about making a quick reference chart for sail trim options for the different points of sail and what each trim option will do do by tightening or loosening it, cuz even after reading so many books about it, I still cant remember it all when im out on the water.... or the wind isnt right to try what ive just read about and want to experiment with.....

does anyone know of a ready made quick reference chart for sail trim?
 
Sep 25, 2008
961
Macgregor & Island Packet VENTURE 25 & IP-38 NORTH EAST, MD
does anyone know of a ready made quick reference chart for sail trim?
How about.............
Don Guillette is author of the immensely popular Sail Trim Chart and the new companion publication, Sail Trim Users Guide. The chart maps your various sail controls to points of sail and wind conditions for more efficient and faster sailing. The Users Guide explains in simple terms why these settings work

........available on this site!!!!
 
Mar 20, 2012
3,983
Cal 34-III, MacGregor 25 Salem, Oregon
How about.............
Don Guillette is author of the immensely popular Sail Trim Chart and the new companion publication, Sail Trim Users Guide. The chart maps your various sail controls to points of sail and wind conditions for more efficient and faster sailing. The Users Guide explains in simple terms why these settings work

........available on this site!!!!
thank you. i need to do some searching to see if that is what i have in mind,
but that might be exactly what im looking for... its too bad there isnt a bigger view of it somewhere... im not one to buy something just becase the title sounds good, but i need to see if the contents are what im interested in:D
 
Jan 1, 2006
8,006
Slickcraft 26 Sailfish
"why should i hoist the main when it sails so well on the genoa alone?" - You shouldn't.

"do you think i am putting too much strain on the rigging running that much jib in that much sustained wind?" - It's a concern but if not in big waves, like in the ocean, it's probably ok. Less strain on the rig is better than more strain on the rig, I think. Many experts say the stiffness of the main sail along the luff while raised supports the mast. And, that without that dismasting is more likely. But they would recommend a reef or double reef, which wouldn't support the luff that much anyway. OK they are the experts. But, all dismasting I have seen or have knowledge of are a result of rigging failure (Stay parting, chainplate failure etc), collision, or mast pumping. Only the third might relate to the mainsail being raised but I would say, in that case, there needed to be more mid mast support - as in running backs, or like in C&C's, a baby stay.
 
May 20, 2004
151
C&C 26 Ghost Lake, Alberta
You need to learn how to trim sails!
It's not about what you're interested in, but what you need to learn.
Guessing sail trim doesn't work, you need to take this seriously!
Sam :)
 
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