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prebend #1992
09/18/08 09:10 PM
09/18/08 09:10 PM
Joined: Oct 2008
Posts: 148
Iowa City IA
Phantom364 Offline OP
Senior Member
Phantom364  Offline OP
Senior Member
Joined: Oct 2008
Posts: 148
Iowa City IA
A posted a picture of the mast prebend. Let me know if it looks like to much
http://phatom364.blogspot.com/

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Re: prebend #1993
09/19/08 02:40 PM
09/19/08 02:40 PM
Joined: Sep 2007
Posts: 37
Toronto, ON
E
Eric Whan Offline
Senior Member
Eric Whan  Offline
Senior Member
E
Joined: Sep 2007
Posts: 37
Toronto, ON
That looks like a massive amount of prebend to me, assuming the backstay is slack. It could be the photo though.

Re: prebend #1994
09/19/08 10:16 PM
09/19/08 10:16 PM
Joined: Oct 2008
Posts: 148
Iowa City IA
Phantom364 Offline OP
Senior Member
Phantom364  Offline OP
Senior Member
Joined: Oct 2008
Posts: 148
Iowa City IA
No it's alot, I can't get rid of it. the forestay is to length, the side stay are tension to 40, no backstay to speak of. I'm going to remeasure the forestay, but I had it odd the boat when I measured and added I think 2' for the deck plate.

Re: prebend #1995
09/20/08 06:46 AM
09/20/08 06:46 AM
Joined: May 2007
Posts: 2,668
Portsmouth, RI
Rhapsody #348 Offline
Past J/30 Class President
Rhapsody #348  Offline
Past J/30 Class President
Joined: May 2007
Posts: 2,668
Portsmouth, RI
See if it straightens some if you slacken the uppers. Check the bend by holding the main halyard against the mast by the boom and look what kind of gap you see up the mast.

Re: prebend #1996
09/23/08 07:20 AM
09/23/08 07:20 AM
Joined: Apr 2003
Posts: 649
Marblehead, MA
dbows Offline
Senior Member
dbows  Offline
Senior Member
Joined: Apr 2003
Posts: 649
Marblehead, MA
I would disconnect the backstay and then work on the rig. You would be suprised how much a "slack" backstay can bend the mast.

David
#397 - Mallorca


David Bows
Mallorca - Hull# 397
~~~~~_/)~_/)~~~~_/)~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~~~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~
Re: prebend #1997
09/23/08 09:18 AM
09/23/08 09:18 AM
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Steve Buzbee Offline
Senior Member
Steve Buzbee  Offline
Senior Member
Joined: Apr 2004
Posts: 457
Highland Park, NJ
Check the position of the mast butt on the cabin sole. It HAS to be 1" back from the angle down in the floor. This has a huge impact on mast prebend/rig tune-every 1/2" back in mast butt position pushes the top of the untensioned rig forward about two feet-so when the rig is tightened, the headstay will have way too much sag, and the mast will have way too much prebend.

Also-check that your lowers are also at 40 (I'm sure they are, but just in case...)


Steve Buzbee
Blue Meanie J/30 #485
Re: prebend #1998
09/23/08 01:46 PM
09/23/08 01:46 PM
Joined: Mar 2007
Posts: 89
Henderson Harbor N.Y.
HHSA Offline
Senior Member
HHSA  Offline
Senior Member
Joined: Mar 2007
Posts: 89
Henderson Harbor N.Y.
That backstay thing worked great for me. I was re-tuning this summer several times and I took the back stay adjuster off first and the last time I took the backstay off all the way during the tuning process. I increased boatspeed and seemed to get much better shape out of my Harrstick main.

Velocity Girl
#278
HHSA

Re: prebend #1999
09/23/08 09:17 PM
09/23/08 09:17 PM
Joined: Jun 2008
Posts: 137
Montreal, Quebec, Canada
Taras Offline
Senior Member
Taras  Offline
Senior Member
Joined: Jun 2008
Posts: 137
Montreal, Quebec, Canada
Steve,....what do you mean 1" back of the angle? I have an '86 model and I hace am oval sleeve that fits into the mast extrusion
I do not have a choice for the position on the sole deck

Taras
Hull #532
BreakAaway
_)

Re: prebend #2000
09/23/08 09:59 PM
09/23/08 09:59 PM
Joined: May 2007
Posts: 2,668
Portsmouth, RI
Rhapsody #348 Offline
Past J/30 Class President
Rhapsody #348  Offline
Past J/30 Class President
Joined: May 2007
Posts: 2,668
Portsmouth, RI
The oval you refer to that the mast fits into must be set so the front of the mast is 1 inch back from the forward edge of the molded step the mast sits on. If it is not, you need to move it. Some are mounted with screws so the plate can be loosened and moved. Others require you to redrill the mounting holes.

Re: prebend #2001
09/23/08 10:29 PM
09/23/08 10:29 PM
Joined: Apr 2007
Posts: 156
kailua, hawaii usa
mango madness Offline
Senior Member
mango madness  Offline
Senior Member
Joined: Apr 2007
Posts: 156
kailua, hawaii usa
"The oval you refer to that the mast fits into must be set so the front of the mast is 1 inch back from the forward edge of the molded step the mast sits on. If it is not, you need to move it. Some are mounted with screws so the plate can be loosened and moved. Others require you to redrill the mounting holes."

Can someone please elaborate on this.I thought I saw pics on this topic on this board somewhere. I want to check mine, as I'm trying to re-tune her now that the deck rebuild is almost complete.


mangomadnessj30.blogspot.com

Former Owner, Mango Madness
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