Author Topic: New mainsheet rigging -- anyone switch to it?  (Read 5907 times)

Doug Stumberger

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New mainsheet rigging -- anyone switch to it?
« on: April 14, 2014, 10:47:16 PM »
So i gather the "fourth" option for mainsheet system passed into class law. Has anyone switched to this system?

Thanks,
Doug S - 174
« Last Edit: April 15, 2014, 12:01:07 PM by Doug Stumberger »

Garrett Johns

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #1 on: April 14, 2014, 11:01:05 PM »
Doug, I believe the purchase is the same, just all at the back of the boom. I wondered if there was going to be too much mainsheet hanging out the back of the boom for gybing where it gets in the way. I know that Jim Sears is using it because I saw a picture of it at the SD NOOD.
Curious to hear from the guys using it. I like how it clears the bridle out of the middle of the boat if the rest of it works ok.
USA 129
Anacortes WA

Craig Wilusz

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #2 on: April 15, 2014, 05:53:47 AM »
We put it on #100.  Love it upwind.  You can easily over sheet the mainsheet upwind and you need to check yourself back there. As the power is really in the back now, it is easier to use the mainsheet in breeze.  The dual bridle in the back tends to reduce the amount of swing you have on the tiller side to side a bit, so there is a little getting used to that.  Downwind in light breeze, there is a lot of mainsheet on the back so it tends to pull the boom inboard a bit in the lite stuff.  Downwind requires much more pull to pump on a wave.  The middle of the boat is really opened up now that there is not a bridle there.  so

+       mainsheet tension upwind
++    ease of use of wind and in breeze
+++  cockpit is opened up
-        need more sheet to pump downwind
-        dual bridle reduce tiller swing a bit
--       down wind in lite stuff

C & D
#100
"Myasasaur"
Craig and Deborah
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Jim Sears

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #3 on: April 16, 2014, 11:54:50 AM »
Yes, I put this new arrangement on #148 and I agree with Craig above.  I'm not the biggest guy, so I REALLY like the extra trimming power.  Now it's no problem to move the mid-boom block to max forward, so there's plenty of room to tack the tiller extension. For downwind, I grab the mainsheet off the boom, just BEHIND the mid-boom block.  Now the sheet is running from my hand to the mid-boom block and then down to the stop-knot at the deck swivel... PLENTY of pumping power.  This also makes gybing the boom easier and safer as without it, there's noting to grab to pull it across.  The transition between trimming modes takes some getting-used-to, so go out and practice it.
F.N.G.
USA-148
SoCal

John Learmonth

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #4 on: April 17, 2014, 08:46:56 PM »
Could someone tell me what the new sytem is or even a pic.
John L
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Tim Carter

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #5 on: April 17, 2014, 10:27:25 PM »
Think 49'er except for mainsheet ratchet and swivel on the floor in std location.
Lt Coast Gov

Garrett Johns

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #6 on: April 17, 2014, 11:09:00 PM »
Could someone tell me what the new sytem is or even a pic.

First 3 pages of attachment cover new mainsheet rules. Diagram "D" on page 3 shows mainsheet configuration covered in this thread
USA 129
Anacortes WA

Doug Stumberger

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #7 on: April 18, 2014, 12:00:45 AM »
Is there any reason to favor a higher bridle-block position instead of a lower bridle-block position?

It seems that on the 49er you can change the bridle length depending on condition, I found this comment on the Mauri site:

"Mainsheet System
The 49er has a floating block [bridle block] that can be raised or lowered depending on wind conditions. To avoid sheeting out in heavy air, raising the block opens the leech by pulling the boom towards the centerline rather than downwards. In lighter wind, lowering the block closes the leech and creates an efficient sail shape."

Is that something that we can, and want, to do on the viper?

Dave Nickerson

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #8 on: April 18, 2014, 07:26:11 AM »
Bridle heights have always been adjustable in the Viper class - just not during a race.  Easy to do with a 12 strand Chinese finger splice.  Whether it provides any real advantage I'm not sure has been shown.
Viper #208 - Noank, CT

Garrett Johns

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #9 on: April 18, 2014, 09:50:49 AM »
Also, changing the "floating block" height would only achieve what Doug mentions if you used it configuration "C" in the referenced rules above. This is how the boat came from the factory. Once you add the spit tail, changing the floating block height only adds or reduces purchase as the split tail takes over leech control and boom centering at that point. We just vang sheet if we feel we need but, my thought is, the problem with dumping main leech tension is that you load up the headstay so its almost counter intuitive
« Last Edit: April 18, 2014, 09:55:52 AM by Garrett Johns »
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Anacortes WA

Justin Scott

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #10 on: July 08, 2014, 11:07:53 PM »
Yes, I put this new arrangement on #148 ...  Now it's no problem to move the mid-boom block to max forward, so there's plenty of room to tack the tiller extension.

The rule constrains how far forward we can move the block. It says:
"The mainsheet must also pass through at least one turning point located mid-boom, with mid-boom defined as the center of the attachment point and located within a range of between 1400 mm to 1750 mm as measured aft from the forward face of the boom."

The rule also specifies that in layout D we must trim from swivel block on the floor.
From time to time, I like to trim from the boom and I have my ratchet block on the boom to facilitate this. This is the only thing that stops me from switching to the system D.

 I have to say in support of system D fans is that I don't particularly like the requirement in the rule to trim from the swivel block . I am not a fan of rules which go beyond the type and position of equipment ......and this rule is unusual because it specifies how we use that equipment. I would feel a tad uncomfortable protesting someone for sheeting from the boom block.   
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Right Coast Refreshments Committee

Jason Hyerstay

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Re: New mainsheet rigging -- anyone switch to it?
« Reply #11 on: July 09, 2014, 12:17:50 PM »
I didn't notice until now that you have to use the swivel cam upwind only in configuration D. It looks like with the other configurations you can trim upwind from the boom. Hmm.

Justin, do you trim from the boom upwind or just downwind?

I have been using Configuration D and I like how it opens the cockpit. I moved the mid-boom block to the max forward allowed by the rules.

jason
Jason Hyerstay - Streetwise - Viper 640 #195 - Lake Champlain Yacht Club, Shelburne, Vermont, USA, http://lcyc.info/racing/viper_640