changing blocks on jib sheet

[willsnow]

Hey guys,
One of my last spring projects is a little deck clean up, involving some new clutches and traveller and stuff. One of the things I need to do is move my jib sheet lead blocks, which have always been right in the path of the lines coming from the clutches to the winch.

My question is: wouldn't I be able to point higher by moving the jibsheet lead blocks as far inboard as space permits? If so, is there a limit to this?

(This is for 100% jib only, genoa goes through turning block on the toe rails and I don't have the deck space for adjustable cars. I might do barber haulers at some point instead)

 

[Joe]

I would experiment with barber hauling to change the sheeting angle first. The sheeting angle is determined by comparing a line from the stem to the block with the boat's centerline. High performance boats will have sheeting angles in the 8-10 degree range.... heavier, comfort oriented vessels will be much higher... 14+. Anyway, play with it, and if you notice an improvement in performance you might consider a more permanent solution.... However, sheeting angles are given serious consideration by boat designers and sail makers based on the boat's intended use........ so I wouldn't necessarily think you'd get a marked improvement in performance without making other adjustments to your boat and its sail inventory.
Therefore, barber hauling is a simple and inexpensive way to get some answers.

The best change is to make sure you can adjust the jib lead's fore and aft position... if it's not on a track.. that would be my first upgrade.

 

[Jackdaw]

Joe pretty much nailed it.

I would just note than on many boats, designers WILL make compromises on gear placement based on overall boat design. This happens to jib tracks all the time.

So play with it. Just don't expect much!

 

[Daveinet]

The angle of your sail to the wind is like the gearing in your transmission. You can keep shifting to a higher gear as long as you increase in speed. At some point, if you are in too high of a gear, your engine does not have enough power to maintain speed. Same with your sail, at some point if the angle of the sail is too steep, its just pushing against the sail sideways, rather than pushing the boat forward. You either have speed or power. The more speed you have, the less power you have. At some point you have less power than what it takes increase the speed, and the sail becomes ineffective.

So that is why you need to experiment. Its hard to say what your boat needs. A heavy boat needs power. A light boat can use speed. As the wind becomes stronger, there is more power available, so technically one can use steeper sail angle as the wind becomes stronger to the point your boat heals over. So not only do you need to experiment, but you also need to test with different amounts of wind.

 

[Meriachee]

The deck eye on the 26c is just about perfect for the standard jib. We screwed with alternate block positions for years, and at the end of the day, that spot was just about perfect in most trim situations.
That of course goes out the window with the 135 or big genny.
If there's a 26c someplace, compare it to the 26d and see it's the same.

 

[thinwater]

What Joe and Jackdaw said. I've move tracks, but ONLY after testing with barberhaulers first AND making a careful study in a range of conditions. Even after extending my keels, I settled on a 16 degree sheeting angle for my cat. She'll still tack through 90 degrees. Pinching higher just slowed her down to much, and I suspect the same may be true of a light, shoal draft boat like the MG 26. You'll think you are going higher, but the GPS will tell a different tale.