fractional rig set up

[mikegambling]

Following a dismasting last year I am trying to set up my new mast and rigging from Z Spars. I am having trouble in achieving any pre bend and in fact when the lowers are tightened there is a curve in the middle of the mast towards the bow. THe rake appears to be correct and I cannot understand why the upper shrouds are not creating prebend. The yacht is a Hunter Horizon 273 with an adjustable back stay which does not figure in the initial set up but acts as an adjuster when sailing. Any advice or assistance gatefully received!!!

 

[Chris_Stannard]

The curve towards the bow is dangerous since if you stress your mast that way it will break. Best bet is to call in an experienced rigger, if you are on the HAMLBE tryGeoff Merritt who is in the phone book. If you are in Cowes, try Barry at Small Craft Rigging.

Chris Stannard

 

[vyv_cox]

I'm not quite sure I understand what you are telling us. In my nomenclature, which I think coincides with that of most other people, pre-bend means that the centre of the mast is set forward relative to the top. On a rig with aft-swept spreaders, tightening the cap shrouds will create this situation. With unswept spreaders the pre-bend is created by babystay or forward lowers tension.

 

[mikegambling]

Mr Cox
You are quite right - my problem is that the upper shrouds are not creating pre bend and in fact after lightly tightening lowers I have a banana shaped mast with a bend at the spreaders towards the stern.

 

[Bergman]

Do you have 3 pairs of shrouds?

I have Z-Spar rig and normally start with intermediates set to tension forestay and give right (roughly) amount of rake.

I then tension lowers up for "right" shape and finally set cap shrouds.

Normally have to have about 3 goes to get right. Only way I have found is to sail the thing and see how it feels.

Only other thought that springs to mind is that the forestay is too long and llower shrouds are pullng at too steep an angle.

I like fractional rig but it can be a swine to set up.

Best of luck