Ropes, dyneema vs polyester

[martti]

Hello

This might be dangerous to ask, but I do it anyway. This only for cruising sailing not for professional racing question.

What is most beneficial for money. Dyneema or polyester rope ?
if question is for cruising and small boat (SO29.2).

Even that for about 20m^2 sail the load may not be huge, it has the rope all a way from top of sail to clutches which is due to stretch (about 15m). And there 2% stretch is more than 0.5%

Comments ?

- Martti

[MartyB]

Martti,

For my Arcadia, I have ALL dynema lines. WHICH, good or bad, allowed me to go to smaller diam lines, which when compared to polyester lines, were pretty close to the same cost. IE, if I needed say a 10mm line in polyester, I could get away with a 6-8 mm line in dynema, both would be about a dollar/euro per foot or meter depending upon how you are pricing things. If you go 8 vs 6 m in the dynema, the price will increase some.

What I liked, is for two lines that both could handle say 2000 lbs of force, the dynema stretched less. To me that is performance no matter how you want to slice it. It may not be much for 30' boats like ours, but still, if I do not have to adjust sails etc, and can enjoy the beer/wine while sailing along, I'm happier, a my spouse does not need to take the tiller, which makes her happier.........

Yes I do race a bit more than most on here, but I bought all the dyneema lines to replace the sta-set line I had, before I started racing my boat. Very happy with them, and they also can be better colour coded IMHO than polyester sta-set style lines.

Marty

[flightdeck]

I'm with Marty or was that Martti......no Marty, at minimum use dyneema on main and genoa (headsail) does make for a cruiser life with the wife when you can set and forget.
If you do go down in rope size make sure your jammers will hold on the smaller diameter, if you don't care about colours then often you can buy a 100meter drum at 25% less.

Cheers

[offshore]

Hi Martti
We sell rope for a living and this question brings up many other questions. First there are the ropes. Standard Polyester Double braid has 12% elongation at break point. Prestretched Polyester Double Braid has 7% elongation at break point and sk60 Dyneema or standard Spectra cored double braid has 5% elongation at break. The dyneema or spectra will be about 90% stronger than the standard polyester so you can go down a size if your blocks and clutches can handle the small rope. Because the spectra/dyneema is so much stronger and lower stretch, shock loads are tranferred directly to the deck fittings and failure is common in undersized fittings. The beauty of these ropes even for a cruising boat is that any trimming adjustment you make is transfered directly to the sail and not absorbed by the stretch in the rope. As wind strength increases polyester ropes stretch and sail settings will change so you need to adjust more often. Don't over winch with spectra/dyneema or you will stetch your sails. We race and cruise and have changed all our ropes to spectra. If nothing else I would change the halyards to spectra or vectran double braid, if the gear will handle it.

Barry

[martti]

Thanks for comment, more always welcome.

I do agree what has been said above. And ropes are not so big cost in overall that price would be best reasoning (My shop have "light dynema 2,8eur/m). At the end, would any cost be too much if there is less interruption for enjoying either just sailing or sailing and refreshments

If rope will stretch, it is mostly when there is most forces, which is high winds ... so also important for cruisers.

Another side of coin what I consider is how is manual handling if rope is 8mm or 10-12mm ? Anyway winches do the hard work when needed.

If you know good web shops with good prices (in EU preferred), those would be nice to know.

- Martti