Tuning my V25 Rigging

[RonRock]

I finally got my new forestay and Johnson lever installed. Now I am having a difficult time getting the rig tuned. It seems whatever I do I am unable to get the forestay tension tight enough. I am using my Loos gauge to read tension. I have a Johnson lever, then turnbuckle on 5/32" forestay. My upper stays are 5/32" going to Stay Adjusters with adjustable holes, connected to Chainplate. Lower stays are 1/8" also going to Stay Adjusters at chainplate. Rear stay I have left loose for tuning.

As I am trying to set my Forestay tension my stays all get way over tensioned before the forestay gets neat the 15% load suggested as a target. From the Loos instruction page I get figures for my 5/32" forestay of 3300 lbs Breaking Strength so set at 500 lbs. 5/32" upper stays @ 350 lbs. And 1/8" shrouds 2100 Breaking Strength @ 240 lbs.

Is there a way that I can raise my forestay tension without raising my upper and lower stays? Should I have the rearstay connected and in tension? From what I have read the rearstay in a fractional rig is not used for tensioning only for sail shape.

 

[centerline]

dont try to set the tension according by percentage of the maximum SWL of the stay cable.... just set it to what is required for the boat....
such as, if you had a 1/4"forestay, you could over tension everything before you got to a 10% loading of the forestay....
Macgregor says in their manual "the rigging must be tight, but not so tight as to play a tune on it"
as you already know, the rear stay does not enter into the rig tensioning equasion....

but no matter how you initially set it up after freshly rigging the boat, after it sets in the sun for a couple of days, you will have to re-tension it... but this should only consist of tightening the forestay a bit....

in my opinion, the loos gauge is only good for balancing the rigging, but for the actual tensioning to get it close, only experience will tell you when its right for your boat, cuz there is no magic number.... there are only three settings,.. too tight, too loose, and close to where it should be, which is variable....

 

[THECUSCUS]

With the bulkhead-less construction of our boats, you won't be able to get all 3 sets set at 15%. What you start to do is make the boat skinnier, as the shrouds start pulling the sides of the boat inwards. The forestay is the important one (for sail trim). Tension in steps. First get the mast up, adj forestay to get rake (don't tension yet), tension upper & lowers to 10%, sight up sail groove in mast and make sure mast is arrow straight (if not adj shrouds to make straight, then check tension and make not of what ones are tighter now and by how much.....keep them at this relative to the others). Check forestay and tension to 10%, your uppers & lowers probably got aliitle loose now. Retension them to your target % (15% if you want that high). Now tension the forestay to your target % (i like the forestay at 15%) and recheck the uppers & lowers. They will have dropped some, but should be all the same (unless one is different due to mast straighten adj). This is as good as it gets. You are correct in that the backstay is loose through all this. There should be just enough on the backstay so it doesn't change the forestay reading. Is your backstay adjustable? If so adjust it until its at 10% and mark the adjuster (you don't want to go more than this ). With the backstay at 10%, note the tension on the forestay has increased and the sides have lessened some. Release the backstay and all should return to your set levels. Not following your numbers of 500lbs for 5/32 forestay and 350lbs for 5/32 uppers. 5/32 is 5/32, and the 350 number looks right. 500 sounds way too much.

 

[RonRock]

Thanks guys, good help here. Makes more sense to adjust tension to the boat and how it works rather than what the Loos chart says.

As far as the numbers I gave, the Loos chart that I was working off, gives specs for 1X19X5/32 at Forestay pounds (500) and Shroud pounds (350)

I doubt now that I will ever get it set to the "correct 15%" since I went up in size with my forestay. I think that it was originally 1/8" but had been bumped up by the PO so I decided to stay with the 5/32" as a safety.


OK one more question. Probably should have been asked first. How do I level the boat when on a trailer? I have been using the stripe along the bottom. But not sure if that is really a good line. Had to start with something.

If it ever stops raining here I'll do some more adjusting.

 

[THECUSCUS]

It all depends on how your boats sits in the water. You to duplicate that on the trailer (as I assume you're looking to set your mast rake). FWIW, the boot stripe is parrallel with the water on my V25. Look at some pictures of your boat for reference and eye ball it on the trailer.