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2024-07-25; 11:50:21 EDT
Member Since
2024-06-18
Posts: 53
Very interesting, I'll keep that in mind thanks!See the original archive post
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 > >> >
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