Adjustable Backstays

[eskfreedom]

As many of you know, we are purchasing a Maple Leaf 42'with an adjustable backstay..I have sailed mostly cutter rigged sloops with NO adjustable backstay; therefore knowing absolutely nothing about them. I was hoping some of you worldy sailors out there would stop to enlighten us...What are the pro's and con's? Thanks

[cal40john]

An adjustable backstay on a masthead rig is used to change the catenary of the forestay. This affects the depth of draft, position of draft of the jib, and leeward sag of the forestay. Basically a loose forestay provides a deeper draft jib for more power, but you can't point as high. Tightening the backstay, which is straightening the forestay, provides a jib that is flatter, less power and can point higher. One additional thing that you have to do when straightening the forestay, is to add tension the jib halyard as the draft will move aft as the sail flattens, so you must move it forward again with halyard tension.

Reaches and off the wind you let the tension off, which provides a deep powerful jib shape.

If you have forward lowers and slotted spreader attachments, you will also be bending the mast (mostly the top half) which has the same effect on the main as the jib.

When you have sails made, tell the sailmaker you have an adjustable backstay, particularly if the boat normally doesn't come with one. They cut the sails differently.

Downside, more stuff to maintain, my hydraulic backstay needs new seals. Possible to damage something if you put too much pressure on. When his boat was new to him, a friend was curious as to what was too much pressure, so he slowly increased the pressure. Decided too much was when the mast made an S shape side to side due to compression and the middle being locked in place with forward and aft lowers. No damage done, but scary to look at. (Same boat as story below.)


One of the interesting things about boats is that they are flexible. Going upwind we would tighten the forestay, when we turned around to go downwind and wanted to put up the spinnaker, if we had forgotten to loosen the forestay, we could not get the pole out of its clips on the deck. The clips had moved close enough together to clamp the pole between them. Loosen the backstay and it came right out.


John

[eskfreedom]

Ok, thank you that description. I went and met the owner and to my amazment it is not an adjustable backstay it's a running backstay. So now i am realy confused.

[cal40john]

Originally Posted by eskfreedom

Ok, thank you that description. I went and met the owner and to my amazment it is not an adjustable backstay it's a running backstay. So now i am realy confused.

A running backstay goes to a point on the mast near where the forestay attaches. (Headstay, top of the mast, forestay, lower down, staysail hanked to it.) A running backstay counteracts the forward pull of the forestay. Since it gets in the way of letting the main out, you tighten the windward one, and loosen the leeward one.