[Capri25] Backstay question -- Reminder on WYC Capri 25 Fleet Rules

steve.truax at comcast.net steve.truax at comcast.net
Tue Dec 30 22:14:56 UTC 2008 

Great reading...

As for why the WYC Capri Fleet bylaws prohibit this type of modification: (mostly for WYC members)

The Capri fleet has debated the bylaws around three fundamental points:

1) One-Design: When does a modification to the original design/specifications change the dynamics of the boat beyond the one-design  concept?

2) Affordability: In the spirit of providing a equal playing field at what point does the cost of a change to the original design/specification inhibit the ability of some boats to keep pace?

3) Safety: Kind of speaks for itself.

Unfortuantely my memory, of the meeting in which the backstay was discussed, cannot recall the exact reasons given for continuing to require the split backstay. However I am certain that all three points above entered into the decision.

Note: I find it interesting that in this thread almost everyone agrees that Catalina did not build the Capri with attention to quality and durability. Yet we all push the boats beyond our own opinion of the construction quality. Such as flying a 155 in 18+ knots of wind then looking for ways to eliminate the resulting sag of the headstay. Just my two cents.

Steve Truax
Persistence 263

-------------- Original message -------------- 
From: "Glenn Selvin" <ghselvin at ix.netcom.com> 
 
We are a Southern California based Capri 25.  In fact, we used the factory tangs as attachment points for our cascading backstay, and upon that backstay upgrade, I decided that I'd better beef up our headstay attachment.

My plan is simply to leave the factory bow fitting in place, and to simply install a new tang, through bolted to the bow.   That tang will not be welded to the bow fitting, as I don't feel like going through the gyrations of removing that factory fitting so as to take it to a welder.  Instead, I'll simply install the new bow tang, laying it right over the existing factory piece.  Thus, the headstay will attach to BOTH the existing factory piece, AND the bow tang through bolted to the bow.

Why Catalina didn't do this to begin with is beyond me.  And as to the Wayzata fleet?  Why not change your bylaws and allow the backstay upgrade?  Its much nicer than the "pinch the wires together" system.
----- Original Message ----- 
From: Mark Hammett 
To: Garry Cooke ; Ruedenberg,Emanuel (Rudy) 
Cc: capri25 at lists.wyc.org ; Kenneth Reiff 
Sent: Tuesday, December 30, 2008 10:38 AM
Subject: Re: [Capri25] Backstay question -- Reminder on WYC Capri 25 Fleet Rules


Greetings Everyone;
I would like to remind all the local Capri 25 Fleet members that are reviewing this discussion thread that the installation of a cascaded backstay is a departure from the local fleet rules - A cascaded backstay was installed on Capri 25 #009 "Divine Inspiration" and was later disallowed because it altered the original running rig as defined by the local rules. For all the out of town Capri's its a great way to get additional purchase and manual force to reduce headstay sag and flex the mast, bending the center forward to force for a flatter main in heavy air. 
Engineering Notes:  Cascading Backstays and Headsail Tacks
Backstay -- The angle of the backstay is very important due to the roach of the standard mainsails. PHRF mains that conform to the original Capri 25 rules (the PHRF standard) have a greater roach than our local Capris. This means that cascading blocks should use the original chainplate positions on the stern and not be lead directly to the eye on the cockpit deck aft of the rudder post. That eye is for the adjuster rig only.  If you cascade to the eye on deck the backstay angle is reduced by as much as 6 inches, which makes low wind tacks and gybes of the mainsail difficult. Especially so if you use a small amount of backstay to create a better entry on the headsail for sailing up wind.  
The headstay plate -- This can be changed to the J24 hardware with minimal alterations (but to bend it with a hammer and vise may weaken the plate).  Several of the local Capris in the WYC fleet have had a 6" L x 3/16" T x 1" W - SS chainplate welded to the original tack plate and have 1 to 3 countersunk 3/8" dia. screws and a reinforcement block on the inside with fender washers and lock nuts. The total length of the chainplate addition is up to the owner but 6 inches (with 2 holes) is typical.  The rub-rail on the bow point does not need to be removed; just slightly altered to accommodate the chainplate thickness and width when installing it underneath. I use a 1" chissle to pry the aluminum rail from the hull.  The chissle will stretch the aluminum nicely without breaking it. Just be gentle and be sure you remove the mounting screws under the rubber (the most forward ones) first.
One good thing about adding the chainplate in the bow -- it you t-bone someone -- the damage to your bow will be significantly reduced -- just ask the guys on Fore Sail who tapped Ham-It-Up! this year...
Happy sailing,   

Mark Hammett
Capri 25 #370
Ham-It-Up!
-----Original Message----- 
From: Garry Cooke 
Sent: Dec 30, 2008 9:53 AM 
To: "Ruedenberg, Emanuel (Rudy)" 
Cc: capri25 at lists.wyc.org, Kenneth Reiff 
Subject: Re: [Capri25] Backstay question 

sorry I noticed a typing error, the 35% should be 25%. 
regards
Garry


On Tue, Dec 30, 2008 at 10:39 AM, Garry Cooke <garry.cooke at gmail.com> wrote:

You need to be careful how much force you are putting into your boat. The backstay tension should be limited to no more than 35% the breaking strain of the backstay wire. If you put too much tension in the rig, you will increase significantly the compression force in the mast and risk damage to the bottom of your boat. I know of two Express 30's where the owners put too much back stay tension and drove the mast down, and cracked the bottom of the boat, and in one case, let water in. I also know of some Viking 28's where the deck has been buckled by too much backstay tension. It would be wise to get a Loos gauge to ensure that you are not over stressing your rig. 


good luck
Garry
Capri 25 'Endeavour' 



On Tue, Dec 30, 2008 at 10:24 AM, Ruedenberg, Emanuel (Rudy) <Emanuel.Ruedenberg at bsci.com> wrote:


You should definitely call Bruce Tamm from 'Tsunami' if he does not answer this email.  He and I know others, have had terrible problems at the bow.  I seem to remember that the force of the forestay separated the foredeck or something…..

good luck

rudy




Emanuel 'Rudy' Ruedenberg
Sr. Quality Engineer
CQE,CQA
Boston Scientific
763-494-1468
Cell 612-201-7238
MS B260




From: capri25-bounces at lists.wyc.org [mailto:capri25-bounces at lists.wyc.org] On Behalf Of Kenneth Reiff
Sent: Tuesday, December 30, 2008 2:28 AM
To: capri25 at lists.wyc.org
Subject: [Capri25] Backstay question


We've replaced the standard "pinch the two wires together" type of backstay adjuster with a very nice, and powerful, cascade system as we've always had problems getting the backstay tight enough to get rid of headstay sag while in breeze.  With this new cascading system, trust me, we're not going to have headstay problems anymore.
 
My question?  I looked below at the very front of the boat in front of that little wooden piece, and the headstay fitting is only through bolted at the top with no back up plate, and only one bolt in the front stem, under the rub rail.  Typical Catalina construction...  cheap.  
 
Has anyone in the Wayzata fleet improved their backstay adjusting arrangement with a more powerful cascade?  And has anyone ever beefed up the headstay piece? I'm thinking of removing it, then welding on a much longer tang, so that I have about three bolts through the stem of the boat, not just one.  Plus, Catalina used no back up plates, only washers, which scares me.  Has anyone put on too much backstay tension and yanked the headstay fitting right off the freaking deck?  Or am I just being paranoid because these boats are built so poorly?  Thoughts on yanking off your headstay fitting would be appreciated.  If you could, please email me at 

-- 
Ken Reiff
Email:  kenreiff at gmail.com
Cell:     562-637-6630


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