[Rhodes22-list] Traditional Mast Backstay problem

[Kenwood _]

Very interesting, I'll keep that in mind thanks!

On Tue, Jul 23, 2024 at 7:04 PM ROGER PIHLAJA <roger_pihlaja at msn.com> wrote:

> If you want to set your boat up to go fast and have good lee helm/weather
> helm balance; then, there is only one correct setting for the forestay
> length.  This length sets the static mast rake angle.  On my boat, the
> optimum static mast rake angle is ~2 degrees aft of straight up and down.
> If the mast is raked forward from this position; then, you will experience
> lee helm and raked aft from this position causes weather helm.  (At least
> with full mainsail and 150% genoa) Also, if wind conditions change; then,
> it is useful to be able to quickly and reproducibly change the backstay
> tension to be able to achieve optimal sail shape.  My backstay adjuster is
> one of my primary sail shaping tools.
>
> Roger Pihlaja
> S/V Dynamic Equilibrium
> 1978. Sanford, MI
>
> Sent from my iPhone
>
> > On Jul 23, 2024, at 1:04 PM, Kenwood _ <kenwood364 at gmail.com> wrote:
> >
> > Everyone i've shown my backstay assembly two has also commented on how
> > homemade it all looks, i do most of my tensioning via the deckhouse and
> > forestay but the block in the back snugs up too. I would prolly have
> liked
> > to see adjustable ends but i guess theres too much slack to takeup back
> > there.
> >
> > Its not too bad to get a set of dies for properly terminating line!
> > Especially if you already have a press McMaster Carr is my goto for swage
> > fittings and the like.
> >
> >> On Tue, Jul 23, 2024 at 8:14 AM ROGER PIHLAJA <roger_pihlaja at msn.com>
> wrote:
> >>
> >> Hi Brian,
> >>
> >> Attached below is a post from the archives re an improvement in the OEM
> >> backstay adjuster.  The OEM backstay adjuster does not lend itself to
> rapid
> >> and reproducible adjustments.  Especially if you want to race your boat,
> >> this is a quick, cheap and effective project.  It doesn't affect your
> PHRF
> >> rating either!
> >>
> >> Roger Pihlaja
> >> S/V Dynamic Equilibrium
> >> 1978  Sanford, MI
> >>
> >> ______________________________________________________
> >> I mounted a Harken #144 swiveling base with #150 CAM-MATIC cam cleat,
> #137
> >> eyestrap, #071 stand-up spring, and a 2.25" dia. block just in front of
> the
> >> starboard side backstay chainplate. The standard backstay adjuster line
> >> will thread up to this assembly like it was designed to be there.
> Thru-bolt
> >> the Harken swivel base to the gunnel with silicone RTV, four #10-24UNC
> X 1"
> >> stainless steel flat head machine screws and use a #10 stainless steel
> >> fender washer under each nut as a backing plate.
> >> Before drilling any holes, thread up the backstay adjuster line and
> >> experiment with the position of the swiveling base. You will find there
> is
> >> a sweet spot just in front of the chainplate where the line will run
> fairly
> >> into the block without chafing on the backstay or blocking the boarding
> >> ladder. Don't use the smaller Harken #205 swiveling base because the
> base
> >> is right near the boarding ladder & sooner or later, someone is bound to
> >> step on the swiveling arm. The Harken 144's swiveling arm can stand up
> to
> >> being stepped on and the 205's can't.
> >> The swiveling arm on the Harken 144 makes trimming the backstay adjuster
> >> very easy from either side of the cockpit. Be sure to mount the
> swiveling
> >> base so that the arc of the arm's movement won't allow the adjuster
> line to
> >> flop overboard. I marked my backstay adjuster line at 2" intervals with
> >> colored magic marker so I can reproduce the backstay tension.
> >> In order for the backstay adjuster to be able to cause any noticeable
> >> difference in lee or weather helm, you need to have the rest of the rig
> >> set-up properly. With only the slack taken out of the backstay tension,
> the
> >> inner (lower) shrouds have to be set quite tight. The outer (upper)
> shrouds
> >> just need to have the slack taken up. Sight up the mast and be certain
> the
> >> mast is not bent or leaning side-to-side or bent fore-and-aft.
> >> The mast should have a slight aft rake to it, about 2 deg max. Now when
> >> you tighten up the backstay, the forward lower shrouds will restrain the
> >> middle of the mast. The head of the mast will be pulled aft. This will
> >> simultaneously take up slack in the forestay and induce a slight bend in
> >> the mast. (Note: NOT recommended with IMF mainsails!)
> >> Tightening up the forestay is desirable for genoa sail shape when
> beating
> >> to weather. If your mainsail is properly cut and not blown out from old
> >> age, the mast bend will cause the mainsail shape to flatten out into an
> >> aerodynamic shape that is better for high winds and beating to weather.
> You
> >> will also move the sail plan's center of effort aft, thus inducing
> weather
> >> helm.
> >> This is an inexpensive modification that works so effortlessly that Stan
> >> ought to consider it as a factory option. My backstay adjuster has been
> >> absolutely bullet proof for 10 hard sailing seasons.
> >> Roger Pihlaja
> >> S/V Dynamic Equilibrium
> >> 07 Jul 98
> >> ________________________________
> >> Thanks for your detailed description. Sounds like a good solution. Did
> you
> >> have any trouble getting to the back ends of the through- bolts? Seems
> like
> >> a long narrow reach. Can you get them from inside the lazarette?
> >> Your mention of IMF mains got me thinking, since that's what we have.
> >> Maybe with the furling tube adding stiffness to the spar, I won't be
> able
> >> to induce much bend anyway, so prudence on cranking down the backstay is
> >> probably wise. It's also likely to have some ill effect on the
> performance
> >> of the furler, if the IMF furling tube isn't straight. My new forestay
> has
> >> a turnbuckle (required by the CDI furler), so I can do more adjusting
> there.
> >> Your recommendations for adjusting the upper and lower shrouds will be
> >> very helpful, too. Thanks again.
> >> Gary Sanford
> >> s/v Raven
> >> 07 Jul 1998
> >> ________________________________
> >> The Harken 144 swiveling base is mounted on the starboard side gunnel
> just
> >> in front of the backstay chainplate. The job will require 2 people, one
> >> down in the lazarette to hold the wrench and a helper up topside to turn
> >> the screwdriver. However, the gunnel is wide enough to easily reach up
> >> there with a wrench. You were probably thinking the swiveling base
> mounted
> >> on the top of the transom, which would be a very long narrow reach to
> get
> >> at the thru-bolts on the backside. It turns out the top of the transom
> >> isn't wide enough to mount the swiveling base.
> >> My roller furler has a turnbuckle as well. This forestay turnbuckle is
> >> used to adjust the static rake of the mast when there is no backstay
> >> tension. For a conventional mainsail, the proper mast rake is about 2
> deg
> >> to the rear. I don't know what an IMF mainsail requires for mast rake.
> You
> >> may have to experiment with mast rake until you get neutral helm. You
> may
> >> find the best you can do is have a slight lee helm in light air
> building up
> >> to neutral helm in a moderate breeze & then weather helm in heavy air.
> With
> >> an IMF mainsail, I would adjust the forward lower shrouds somewhat
> looser.
> >> Then, increasing backstay tension would simply increase the rearward
> rake
> >> of the mast without bending the mast. This would get you the forestay
> >> tension you need to be able to point to windward. The chances are your
> IMF
> >> mainsail isn't designed to respond to mast bend anyway. Remember, I
> have a
> >> fully battened conventional mainsail & I specified my mast bend
> parameters
> >> to the sailmaker when I ordered the sail. I would imagine bending an IMF
> >> mast & then operating the furling mechanism might cause the mainsail to
> >> chafe inside the mast & put a lot of stress on the furling mechanism's
> >> bearings. Is an IMF mast much stiffer than a conventional mast? I've
> never
> >> seen one off the boat. How much heavier is an IMF mast?
> >> Roger Pihlaja
> >> S/V Dynamic Equilibrium
> >> 08 Jul 98
> >> ________________________________
> >> Had the IMF apart 2 weeks ago. Any rake would be bad news, since the
> >> mainsail is wrapping around a tube with roller/spacers top and bottom.
> If
> >> the tube changes distances to the mast wall I do not think the sail
> would
> >> go in (i.e. the whole thing would jam up). The IMF is about two inches
> more
> >> fore/aft and about ½ to 1-inch greater in width, than other masts on
> boats
> >> that size. It’s very stiff, but I have never seen the GB standard mast.
> >> MJM
> >> ________________________________
> >> The OD of the forestay wire & the rigidity of the headsail foil have
> very
> >> little to do with forestay sag. Forestay sag is primarily controlled by
> the
> >> amount of backstay tension + some secondary & tertiary effects caused by
> >> other details related to the way the standing rigging is setup. The use
> of
> >> 3/16" OD wire for the forestay permits the backstay adjuster to be
> really
> >> cranked down hard with no fear of forestay wire stretch or fatigue
> cycling.
> >> The use of the larger diameter wire also introduces an additional safety
> >> factor to compensate for corrosion, mechanical damage, etc.
> >> I have my backstay adjuster setup on a Harken 144 swivel base, 150
> >> Cam-Matic cleat, 071 stand-up spring, & 001 single 2.25" block mounted
> on
> >> the starboard side gunnel right at the transom. Backstay tension is
> quickly
> >> adjusted by pulling on the backstay control line thru the Cam-Matic
> cleat.
> >> The 144 swivel base & 150 Cam-Matic cleat allow the backstay tension to
> be
> >> adjusted from virtually any helm position. I used the 144 swivel base
> >> because the backstay adjuster is right near the boarding ladder where it
> >> might be accidentally stepped on. The large 144 swivel base is rigid
> enough
> >> to step on without damage, while the smaller Harken swivel bases can't
> take
> >> such abuse. The backstay adjuster control line is striped every 2" so
> that
> >> the backstay tension is reproducible.
> >> My standing rigging is setup such that increasing the backstay tension
> >> simultaneously reduces headstay sag & bends the mast for flattening the
> >> mainsail. Both actions are desirable for sail shaping in heavy air. I
> have
> >> a fully battened conventional mainsail, which is cut very roachy & is
> >> designed to respond to mast bend by flattening. I use only one mainsail,
> >> but it has 2 jiffy reef points. Needless to say, backstay tension is
> one of
> >> the most important sail shaping controls on Dynamic Equilibrium.
> >> Good grief! I just gave away a couple more racing secrets! Hopefully, no
> >> one else is listening.
> >> I guess I don't understand your question re noticing any difference when
> >> the sail is fully extended given the weight. The only fully nylon sails
> are
> >> spinnakers. Did you mean, have I ever noticed a difference in light air
> >> behavior between a Dacron genoa & my Cruise-Lam genoa? If that's your
> >> question, the answer is the bi-radial Cruise-Lam genoa has a better sail
> >> shape under all conditions vs. the standard Dacron genoa. In heavy air,
> the
> >> Cruise-Lam + bi-radial construction genoa's sail shape is much better as
> >> the standard Dacron + cross-cut construction genoa becomes hopelessly
> >> distorted.
> >> The secret of Cruise-Lam's longevity is the Dacron outer skins. The
> Dacron
> >> provides chafe, UV, fatigue resistance, & environmental pollution
> >> protection. The reinforcing Kevlar scrims & Mylar film core are buried
> >> inside the composite sandwich & are thus protected from the harsh
> outside
> >> world. Unprotected Kevlar & Mylar would be expected to only last one
> season
> >> or less in the marine environment.
> >> Roger Pihlaja
> >> S/V Dynamic Equilibrium
> >> 12 Jan 2002
> >> ________________________________
> >> From: ROGER PIHLAJA <roger_pihlaja at msn.com>
> >> Sent: Monday, July 22, 2024 2:06 PM
> >> To: The Rhodes 22 Email List <rhodes22-list at rhodes22.org>
> >> Subject: Re: [Rhodes22-list] Traditional Mast Backstay problem
> >>
> >> Hi Brian,
> >>
> >> On S/V Dynamic Equilibrium, my 1978 Rhodes 22, I had a local wire rope
> >> rigging shop duplicate what I had when it was time to replace the double
> >> backstays.  As you described, it is one piece of cable bent in the
> middle
> >> around a SS thimble.  My backstay adjuster and sockets for the traveler
> bar
> >> are also like yours.  I used this backstay for many years with the GBI
> gen
> >> 2 traveler bar.  When it came time to upgrade to the latest Gen 3
> traveler,
> >> it slipped right into place using the same backstays and sockets.
> >>
> >> Roger Pihlaja
> >> S/V Dynamic Equilibrium
> >> 1978. Sanford, MI
> >> Sent from my iPhone
> >>
> >>> On Jul 22, 2024, at 1:46 PM, Brian Ferguson <
> >> brian.a.ferguson76 at gmail.com> wrote:
> >>>
> >>> To my fellow Rhodes traditional mast-ers,
> >>> My current backstay consists of a single continuous piece of ss cable
> run
> >>> bent through a thimble to mark the halfway point The thimble is the
> >>> connecting point to the mast head. The two cable ends have stay
> >> adjusters.
> >>> There are two single blocks on each side for a total of four, with one
> of
> >>> which having a becket. Those blocks by the way, are attached to the
> >>> backstay cable with a short piece of cable swaged on to the mainline.
> >>> (Describing it is easier than drawing a picture). I know the blocks are
> >> for
> >>> increasing the tension and adjusting underway. Bottom line, everything
> >>> looks very homemade.
> >>> The last time I asked about this, everyone said to purchase a new
> >> assembly
> >>> with the traveler bar from GB. Does the latest GB version work for a
> >>> traditional mast? Is there a height difference between the IMF mast and
> >> the
> >>> traditional? Or do I just make a copy of what I have?
> >>> Current price of the Backstay assembly is $425 if the webpage prices
> are
> >>> still accurate. Next email is to Mr Gabriel.
> >>> Thanks all.
> >>> Brian
> >>> NewIn76
> >>
>