My spin pole received a 15 degree bend about three weeks ago. A reef knot on the bow slipped during a pitchpole type event. The pole didn't kink but it sure had a 'wow' in it. The fisherman type knots might be better with the spectra lines.

Dyneema is just fine. Just set up your pole with some noticeable prebend and the creep will only relax it a little bit. Dyneema has about 2 % creep I think but after that has settled it won't stretch any further at all. So compensate for this by making your lines a little too short initially. Only a little !

Besides I've been hanging (trapezing) of 3 mm dyneema (hard outer mantle) for many seasons now. Using a fishermans hitch and bowlines. Also my spi luff is handing off a 2.5 low grade dyneema line. The lines haven't given way yet. Mind you I hate spectra with a passion. It is nowhere like true dyneema in my opinion and it will snap.

D12 versions of dyneema (the new rage) are very slippery on the outside and these line have inferiour knot holding characteristics. So just go for the plain dyneema with hard outer mantle (also cheaper) and you are set.

Wouter

I had the same problem when I did my bridle but in the end I did eye splices in both ends then wrapped the eye splice around the fitting once which took up the length that "creeped." For those who haven't done an eye splice in plain spectra or dyneema 12 strand it is VERY easy after a little practice. The size you can use for a bridle can be so small that it is really cheap to buy extra to practice. Getting the length right can be a little tricky but you will get it

Hi Will,

I have worked out how I'm going to do it, I just haven't done it yet!

What I intend to do this winter is fit a pair of Harken through deck micro sheaves to the pole tip, set horizontally, one on either side of the pole. I'll then fit an internal system with a single line exiting under the pole near the mainbeam with a clamcleat to lock it. The two tails from this line will exit the sheaves on either side of the pole tip and I'll splice hardeyes onto them. Then the dyneema pole guys will have spring clips (or maybe I'll use Inglefield or 'sister' clips) to attach them to the adjustable tails. This way I should be able to pretension the pole even on the water......

I tought Dyneema and Spectra was the same fibres, just different marketing names in the US and Europe?

We have used dyneema bridles for the spi pole bridle the last three years, no problems yet. Just need to make sure that you make the loops correctly. Either by splicing or threading back inside itself with a knot at the end and a small whipping (John, please dont.. <img src="http://www.catsailor.com/forums/images/graemlins/wink.gif" alt="" /> ).

The dyneema I'm talking about is the older kind, not the hollow D12 line.

I've yet to see a good use for the D12 line. It is simply to slippery for most uses.

I'm told often that dyneema and spectra are the same but for some reason I've always suspected a quality difference between them.

Wouter

I've done some research into this many years ago and from what I recall, they were virtually identical in chemistry and manufacture, except that dyneema had one more process that made it less brittle. I've heard many people claim that spectra has snapped on them when the load "bounces".

Wikipedia
Marlow Ropes
Honeywell - Spectra
DSM - Dyneema

I'd almost consider using Vectran for all fixed rope systems; no creep, good toughness, abrasion resistance and UV resistance plus I think it actually gets stronger when knotted!...Will have to look for a price next time I head to the chandlery.
Vectran

Having been a bit disappointed with wire stays ( weight, non adjustability, hard on the body when bounced into, tendancy to kink when derigging amongst other things )I've started using D12 for the main stays and trapeze wires. Seems to work really well but does tend to " stretch " a little when first made and you really must follow manufacturers guidelines when splicing ( as I found out when my trapeze let go . Has all sorts of advantages mainly being 1/4 the weight of wire and stronger for the same diameter, and what I really like is that you can adjust the length to your hearts desire ( I'm even considering doing away with adjusters as once you have your boat dialled in, how often do you change mast rake ). Don't be put off by the splicing as it really only takes minutes per eye. To date I have had only positives and no negatives. For anybody building and prototyping rigs etc it must be a real winner. Longetivity seems as good as expected, I've had a front stay and bridle in use for over 2 years now and there doesn't seem any real wear or degradation of the rope.

That is surprising Wayne. "Everybody" I have been in touch with so far has advised against synthetic shrouds and forestays.
How do you adjust the stays, and tension the rig? Have you bought some of Precourts fittings, or do you have your own solution?

BTW: We have used spectra lines as trapeze lines for.. it must be 4 years now. Even with 110kg's on the trapeze and jumping from wave to wave they have been solid.

I'm interested to hear why you have been advised against synthetic shrouds, most big funded racing boats use synthetic and Farrier has now moved across to carbon fibre mounts with synthetic rigging. Enlighten me on the why nots as I maybe making a big mistake.

regarding my spin pole setup, I have the original blade setup, but the only change I did was make the lines maybe six inches or seven inches longer where I can wrap the pole twice. Then I make a square not with the bitter ends and keeper knots on each end. So far a year of sailing and no problems at all.

Wayne,

creep, stretching (need to adjust the rigging on the water), fatigue (especially where our stays bend around a rotating mast), difficulty with terminals/eyes, lack of easy adjustment and longevity vs. cost has been the reasons quoted.
I like the idea of synthetic rigging, so I am hoping for positive reports from you <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

How did you rig the shrouds and ensure adjustability?

I'm using Robi's system and I think Seth Stern does as well.

What's the advantage of doing it this way? I don't think I fully understand the description - any photos?

I've been experimenting with quicker ways to rig the spi pole, but without great success.

Paul

The advantage is simplicity. Take two lines, each with a stopper knot in one end. Run them through the bows and wrap around the spin pole. Straddle the pole and use your weight to get the desired prebend; then just tie a square knot. Trim to the length desired.

OK, so that sounds like one knot where I currently tie two - an improvement. But what stops the pole moving sideways along the line under force?

Paul

See

http://www.ahpc.com.au/pdf/Capricorn%20F18%20Owners%20Manual%20v1.2.pdf

Check page 16--that's the knot and system I use; it's simple to adjust and put together/take apart.

Wrapping the line around the spinnaker pole atleast two rounds. This will prevent it from moving left to right. I will take photos and post em in the next few days.