I saw a few older conversations on updating to a 10:1 . I have a Prindle 19mx with an original 6:1 sheet. I see a great deal on a 10:1 but not sure of the advantages . I am not racing and split seconds not a concern, but I do appraciate more modern updates to the boat. I know the cons of the extra line on the tramp and the slower reaction of the line coming in or going out . Are there worth while advantages on this type of boat ? And how much line is required on these ?
I would def suggest an upgrade to a modern block if you have the funds
8:1 is enough
9:1 nice
10:1 prob overkill if your not a racer
advantages :
more purchases = less energy needed from skipper to sheet in full sail or hold a sheeted sail (you know the cons)
lighter gear
typically lower profile (more range)
Ladies dig new gear (jk)
how much line? i dunno your boat that well but lets say 10-15% more per additional purchase?
you MIGHT be able to make up for a few purchases with a longer travler line but if your upgrading - time for a nice new tapered mainsheet too
MN3
MN3 wrote:
more purchases = less energy needed from skipper to sheet in full sail or hold a sheeted sail
not exaclty
What is reduced is the force, times more sheet lenght to pull equals the same energy to sheet in.
Energy to hold the sail is 0 in both cases. Force is different
I upgraded from a 7:1 to a 9:1 on my Nacra 5.7. I would never go back.
Dave Bonin
1981 Nacra 5.2
Andinista wrote: [quote=MN3]
more purchases = less energy needed from skipper to sheet in full sail or hold a sheeted sail
not exaclty
What is reduced is the force, times more sheet lenght to pull equals the same energy to sheet in.
Energy to hold the sail is 0 in both cases. Force is different
Technically you are correct -
i was over simplifying the terms, trying not to get too scientific
to the human at the end of the blocks: (ceteris paribus)
you can sheet all day and feel less muscle fatigue than if you had a lesser purchase system
and expend less Joules (1 kg*(m/s)^2) to hold a sheeted mainsheet in the same position over any length of time
MN3
Just spend the Christmas money and get the new Harken GP (Grand-Prix) system. Can go 10;1, 11:1, or 12:1!
http://www.harken.com/productdetail.aspx?id=47404&taxid=8923
Wow..this can double duty as as the marina boat lift on windless days .
$1500 !! Santa was not that generous . I think I'll keep with the 10:1 idea .
Sent you a pm Emmitt.
Dave
MN3 wrote:
to the human at the end of the blocks: (ceteris paribus)you can sheet all day and feel less muscle fatigue than if you had a lesser purchase system
and expend less Joules (1 kg*(m/s)^2) to hold a sheeted mainsheet in the same position over any length of time
See it this way:
Do you feel less hungry at the end of the day? No, because you haven't spent less joules.
Your muscles feel different? Yes, because you applied less Newtons.
equal need of beer will verify that the experiment was ceteris paribus.
Andinista wrote: Your muscles feel different? Yes, because you applied less Newtons.
equal need of beer will verify that the experiment was ceteris paribus.
Wait- did you say beer?
uh, you lost me after "less Joules (1 kg*(m/s)^2)".
Last time I dealt with "joules" it was on a defibrillator.
I prefer this equation when talking about catamarans:
Ballast = Bikinis x Beer
I'm sure that there are values to the B3 equation above that would allow calculation of Total Fun Acquired, or Belches per Knot...
Forgive the diversion.
i recall having a conversation with jack young of Nacra years ago regarding the dangers of having too much purchase for the sail on a cat. while it's easier to 'sheet-in' with a 10:1 than a 9:1, 8:1, 7:1, etc. he said the reason they didn't put greater purchase on boats is to reduce the chance that the mainsail could be pulled with such force as to damage the sail or 'overbend' the mast.
j
I can understand this , but why then do all the performance cats now come with the 10:1 ? Capricorn, C2, Nacra 17 Olympic , Nacra 20 , Tornado..etc..etc ? Stronger Carbon masts ?
emmettv wrote: Stronger Carbon masts ?
Yes, and completely different sail cloth/construction techniques on the mainsail.
emmettv wrote: I can understand this , but why then do all the performance cats now come with the 10:1 ? Capricorn, C2, Nacra 17 Olympic , Nacra 20 , Tornado..etc..etc ? Stronger Carbon masts ?
yes and no
Cap, C2 - older N20's and tornado's had alum masts
but bendier than older extrusions
and did not come with 10:1
plus as mentioned the cloth is very different and holds shape much longer than dacron
Edited by MN3 on Jan 01, 2018 - 10:27 AM.
MN3