Is anyone or has anyone used dyneema, spectra or any other similar materials for 2:1 jib halyards or any other rigging?

Yes; Dan tried it for a jib halyard a couple of years ago, but was not confident in it for long where the load reduced its dimension substantially around the halyard sheave!  We, and others, have tried it for lowers, but the amount of elongation there is as the knots and splices bed in (I'm not talking stretch here) made it unrealistic, bearing in mind how fine the tuning is on these controls.  We fitted vectran lowers for the first race of the champs this year, and they elongated so much, so quickly, that I disappeared below decks to shorten them a couple of feet after about 15 mins sailing (and was sea sick while doing it), and by the time the start came the only way we could stop the mast reverting to kit form as it bent so excessively was to have full lowers, and the mast fully upright! A v strange combination...

It is fantastic for pullers, though, where it stows away really easily and is kind to the leach/ clew of the jib.  We have dispensed with it elsewhere..

You are welcome to give it a try though!!

GGGGGGGG

I've made a kicker out of lightening rope and it's great. As Graham mentioned it's good for pullers too, and i'm going to try it as a main halyard after the wire one broke and see if it lasts longer than 6 weeks!

Another thing i've found it useful for are pole downhauls and the rope that attaches to the car of the traveller on square hoops.

As for a jib halyard, on paper it should be fine once the splices have bedded in, it's calculating how much they will move and given the load here i'd say a lot!

As previous have re-rigged 22yr old boat with it everyware except jib halliard. mainly used spectra & dyneema you can really reduce diameter and hense weight. good cleats are essential & whip the eye-splices, we have removed the cover sheath to further save weight (we had a lot to lose!)on some of the sheets. Were looking at PBO for jib halliard & shroud adjustment so will note comments with interest.
As it's Christmas you should think ahead & buy your crew some gloves though.  Barry.

I'm reluctant to use it (Lightening rope) on anything that cleats because it will eat the cleat jaws within a few months. It's too hard wearing for that kind of thing!

Spectra is probably better, but i think any diameter less than 4mm for control lines is cruelty!

Use bungy on everything ,that way when a gust hits you dont have to touch anything.Just hike !

I have used a 5mm vectran halyard on an Int 14 with no problems at all. PBO as I understand may have stability problems with UV

Don't know about that.  I once used a piece of 8mm Vectran rope for a mainSHEET, with a small length of it stripped near one end, and the damn thing snapped clean in half right in the middle of the exposed section, no knots or anything. It was a year old. 

There must have been all of 10Kg of load in it!!

I wouldn't use vectran for hanging my washing out on. PBO is pretty similar I believe.

??? Cant understand that.  I have had Vectran on the puller of both present boat and the last one for some years now with no problems at all, ditto kicker and spinny downhauls, all of which take a fair old load.  I have replaced them when they looked a bit scruffy but that after well over a year and no breakages.  The plaited rope has been the one I have found works well - lightening rope is I think the same - as the cover of the other frays and parts fairly readily.

I know. This shouldn't happen, but it did! It was a roll-end piece of 8mm Vectran-cored rope that I was given by a large yacht rigger. Probably used for runner tails and the like. 

I stripped some of the cover off at one end for about a metre, don't really know why, but I did. After a year, it snapped right in the middle of the stripped section. Oh, humm, okay, maybe 2 years!! But it snapped never the less.

Whats PBO?

It stands for Poly...B.....(really long word)..O.......
Also has a trade name of Zylon.

It's a super strong fibre originally developed for its heat-resistance, but which has a higher modulus and strength than any other fibre. Doesn't creep either, like spectra. It would be the undisputed king of fibres if it didn't deteriorate so badly in UV light.

polyphenylenebenzobisoxazole

Whats PBO normally known as is what i meant :)

Is it aka lightening, herzog etc?

Nothing, just PBO or Zylon. PBO is an abbreviation of the chemical name, Zylon is a brand name of PBO manufactured by Toyobo corporation. 

See http://www.toyobo.co.jp/e/seihin/kc/pbo/menu/fra_menu_en.htm.

Lightning and herzog ropes aren't PBO. I think they're mainly spectra, although I'm not sure. Anyone know? PBO is extremely cutting edge, and not very widely used in the marine industry, mainly due to cost and it's UV performance.

Lighting is a mix of UHMPE (dyneema or spectra trade names) and vectran.

Vectran isn't good exposed to UV which might explain the breakage in the earlier post. Stuff like Marlow's V12 which is vectran without a cover has a UV resistant coating.

Some further reading for those interested...

PBO 

Coated is great .we used it on the spokes of me mountain bike. As to using it for  standing rigging and  halyards its great. Next step is not to use halyards ,only on the spinnaker.The other two are a waste of time. Its a lot faster .The rig and sails can be set up better and more precise.without the use of gib and main halyards. Cost of PBO coated we use is 80pence a mtr.

Regards
Boy

PBO COATED 

Available  1mm  to 60mm thick. Its the stuff that holding Ellen's mast up, and most of the Vendee Globe fleet . Will it work on Merlins,
Who Knows, CARBON DOESN'T

Boy!

Confirmation that Vectran is suitable for kickers: the new s/s ISP high load ball bearing sheave on our boom exploded last Tuesday as we applied just a tad more kicker - the Vectran was declared the winner!

Just off to put 5mm bolts through the spindles on the replacement kicker, and jib halyards blocks, ho hum...

I've used the stuff for years with no trouble at all as lower runners on Ocean Racers, Broads River Cruisers, Dragons and anywhere the rules allow, however I've got 50-1 at Ladbrokes that Ellen Mcarthurs rig will collapse, she's such a gallant loser, surely this time she wil not do it?Though I'll be the first to cheer if she does.