I'm at the point where I am slowly replacing my line. I have quickly learned that rope is surprisingly expensive.

My next task is the jib line. I've been told that the newer lines (especially those with dyneema) are so strong that you can use slightly smaller diameter line. I'm at the point of replacing my jib lines. Are lines on cats a standard diameter or does each boat differ based upon the manufacturer's design?

The class specs for my Dart say "09 min", if I'm reading it correctly. That can't be a minimum of 9 mm, so I'm not sure what that measurement means.

Short of taking the line off the boat, how can be assured I'm buying the correct line?

Dana

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Dana, Holly, Emma & Hannah

LJ/Stu's Dart 18 (Sold! :( )
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Some online shops have fairly good discount rope, even with dyneema core (nautos.com comes to mind). I have found that for halyards, etc it's ok.

But for sheets, specially mainsheet where grip is important, I want the grippiest rope, and grippiest gloves. Modern rigs like the Dart 18 need good leech tension. I currently use Atlas gloves and Samson MLX 8mm and super happy.

It's true, Dyneema lines can be *much* thinner, but they get hard to grip, and can even cut you. A US Olympian lost a finger recently to a dyneema traveler line wrapped around his hand. So I'd go down a bit so that they run smooth through the blocks, but not much.

Dart 18 line recommendations - https://www.sailingchandl…s-mainsheet-halyard.html

i personally love the dyneema blend line for a mainsheet
it is light, soft and gets fuzzy
it doesn't retain water - I prefer Robline Racing Sheet - not sure if its still being made
Salsa is a close second and cheaper but only comes in Viva la mexico coloring so using it in more than one location may not be optimal

these lines are too light to get the whipping action needed to get the jib blocks out of the cleat so i recommend using regular robline (or other) XLS line Xtra low stretch) for the jib - i happen to have dyneema cored (robline dingy control line) but it is overkill on a jib (i have wings that i sometimes use so the extra weight is nice to have when uncleating from so far away)


I WOULD take off your sheets and bring it to the store w you when you replace your line - otherwise you are probably guessing on the exact diam and length

I think most of us are using 5/16" (8mm) or 3/8" for the mainsheet, smaller runs smoother thru multiple purchase blocks, and is harder on your hands, bigger is more comfortable, but runs a little slower. 5/16" is probably fine for your jib sheet, as the load you're applying is not large. And I doubt a dyneema or vectran cored line is very important for the jibsheet, more so for the mainsheet. You could also check riggingonly.com and sailcare.com for slightly better pricing, although more limited selection than say apsltd.com.

martin_langhoff

Dart 18 line recommendations - https://www.sailingchandl…s-mainsheet-halyard.html

Thanks a bunch for this reference!

MN3

i personally love the dyneema blend line for a mainsheet
it is light, soft and gets fuzzy
it doesn't retain water

Just replaced my mainsheet line with this. Need to get out a bit more to get more experience with it, but it seems like I can sheet in further using the new line.

davefarmer

I think most of us are using 5/16" (8mm) or 3/8" for the mainsheet, smaller runs smoother thru multiple purchase blocks, and is harder on your hands, bigger is more comfortable, but runs a little slower. 5/16" is probably fine for your jib sheet, as the load you're applying is not large.

So I guess I was reading the specs right! My replacement main sheet line seems slightly smaller in diameter, so I suspect it is 5/16", which also means I am now class illegal.

I'm imagining that I can go anywhere from 5/16" to 3/8" to 7/16" for the jib line. Martin's reference tells me the length is 10 meters, but I've added length to small line that runs up to the clew of the jib. I understand that means that my jib line may not need to be that long. And I've got a ton of line on my tramp.

What's the best way of determining the true needed length?

Dana

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Dana, Holly, Emma & Hannah

LJ/Stu's Dart 18 (Sold! :( )
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davefarmer

I think most of us are using 5/16" (8mm) or 3/8" for the mainsheet, smaller runs smoother thru multiple purchase blocks, and is harder on your hands, bigger is more comfortable, but runs a little slower. 5/16" is probably fine for your jib sheet, as the load you're applying is not large. And I doubt a dyneema or vectran cored line is very important for the jibsheet, more so for the mainsheet. You could also check riggingonly.com and sailcare.com for slightly better pricing, although more limited selection than say apsltd.com.

I also use 3/8" for the mainsheet and 5/16" for the jib - fairly common.

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Martin's reference tells me the length is 10 meters, but I've added length to small line that runs up to the clew of the jib. I understand that means that my jib line may not need to be that long. And I've got a ton of line on my tramp.

What's the best way of determining the true needed length?

Likely not the best way, but I simply set it up at a few more feet than I thought I needed and then went out and sailed at various tacks and on the wire. Looked at worst case scenarios when running down wind and farthest back on hull while on the wire. If I still had "too much" line on the tramp, I noted it and shortened it when back at the beach

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Supercat 15
Windrider 17
Several Sunfish and Sunfish clones
Ratboat built from Zuma and Sunfish parts
Shallow water sailor in the Delaware Bay
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If the jib sheet is setup "endless/continuous", I make an overhand knot to take up what I think is excess line, it's easy to adjust while sailing looking for that "worst case".

For two sheet ends, or for the mainsheet, I move the figure eight knot "up" the sheet to where I'd cut, sail a bit until I'm comfortable.

Quote

Likely not the best way, but I simply set it up at a few more feet than I thought I needed and then went out and sailed at various tacks and on the wire. Looked at worst case scenarios when running down wind and farthest back on hull while on the wire. If I still had "too much" line on the tramp, I noted it and shortened it when back at the beach.

spot on!

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What's the best way of determining the true needed length?

there are many ways:

when i purchase at a real line shop They have a line counter (machine you pull line through)
at the Tackle Shack they use a 5' ruler with nails on it, on a bench they pull line off the roll at and each wrap = 10' (actually they just use 1 wrap as a 5' index and hand wrap up the desired amount)

When I am home i take any sheet and measure 3' out. then wrap the rest up or of the line in the same 3' lengths
number of wraps x 3 = length in feet

same for the main - either on the blocks or off the blocks
Off the blocks are much more accurate



Edited by MN3 on May 08, 2018 - 05:13 PM.

dartsailors

so I suspect it is 5/16", which also means I am now class illegal.

Who cares in this case?
Have you ever heard of someone getting in trouble with a race committee for having the wrong size main sheet - especially in this era of crazy-strong blended lines?
If they are concerned at all, they look for good quality line in good condition.

If someone said anything to you about being class legal with your Dart, you have met the local Rules Lawyer, who points out stuff like that so he can complain about cheating when you beat him.

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Sheet In!
Bob
_/)_____/)_/)____/)____/)_____/)/)__________/)__
Prindle 18-2 #244 "Wakizashi"
Prindle 16 #3690 "Pegasus" Sold (sigh)
AZ Multihull Fleet 42 member
(Way) Past Commodore of Prindle Fleet 14
Arizona, USA
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by jib line i assume u r referring to line utilized to hoist/raise jib; original Dart ropes superb, very oily,durable and strong but unnecessarily so for jib-raising the jib is not strenuous and dart 18 jibs are doily size-perhaps a narrower diameter rope dimension leaves more space inside the mast ,since thats where both jib and main lines are located on Dart 18. in my opinion main "line" must be of very durable strength without much stretch in the main line-I previously expressed opinion on this site that its safer in high wind conditions to NOT lock the main line after hoisting but to tie it down to a cleat (So you dont want stretch in the line because main will come down slightly) because u cant take/lower main on Dart 18 when underway! the critics said that put twice the stress on the mast, but i know from experience when a big blow comes out of nowhere lowering the main is quicker than reefing it in. I also now believe typical Dart 18 main sheet tied/knotted to traveler leaves too short a main sheet line in emergencies-in order to avoid a capsize my main sheet lines are now 5 feet longer. cleat placement debatable, prior owner of one of my Dart 18s placed oversized cleats not in rear of mast causing jib sheets to snare/get caught

I’m pretty sure the original post was questioning jib and mainsheets, not halyards

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Supercat 15
Windrider 17
Several Sunfish and Sunfish clones
Ratboat built from Zuma and Sunfish parts
Shallow water sailor in the Delaware Bay
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I stand corrected ,except for comments on utilizing longer main sheet from blocks to traveler-if hit by humongus gust and to avert capsize u immediately uncleat/release main, on Dart 18 length of main sheet prevents main sail from completely swinging free to spill wind, longer main sheet allows main to come into contact with side stay/shroud and spill wind- i just replaced main sheet on my Ft,Lauderdale Dart 18 and will change the main sheet on my Fire Isle Dart 18 too, if it ever stops raining in the northeast, I have 7to1 harken blocks on Fla Dart and narrowed the diameter of main sheet /line to 5/16, replaced jib halyard with 1/4 inch, more than adequate & more space inside mast.