Re: [Cal_Boats] Re: Cal31 Back stay

I think maybe a clarification of terms may be needed here for some, including me. Any mast can "RAKE" right? Straight up, a little aft, or a little forward, but it is done with the standing rigging. Mast "BEND" is, as it states, bending the mast in the middle to flatten the main, (and tighten the forestay)right? So, with a tree trunk mast, when you adjust the backstay all you are doing is raking the mast back a bit as to tighten the headstay, Right? So if your forward lowers are too tight you are either putting way too much load on the system or not getting much rake, Right? A thinner bendier mast gives you more options, but it is up to the sailmaker to achieve the proper design for the different masts, Right? Daniel Casey "AirTime" Cal 9.2R #75 Santa Barbara ************************************** See what's new at http://www.aol.com

I'ld say that's about right - but when discussing bendy masts, you might throw in masthead vs. fractional rigs. I don't know just how much the masthead of a stiff mast masthead rig really moves as the backstay is tensioned and released. At a SWAG, if you cranked in 3 inches on the backstay, you would be seeing about 1 inch or so aft movement at the masthead. Just how much that would add tension to to lowers I don't know - and that would depend on at least three parameters - the ratio between the distance from the forward lower chainplate to the masthead and the lower attachement, the ratio between the fore/aft and athwart angles of the lower. Then you would need the elastic modulus for the lower wire. To complicated for me. If it was me, I would just put a tension guage on the lowers and see what happened as I varied the backstay tension using the turnbuckle. If it looks okay then go ahead with an adjustable backstay. If it was bad news - you could always add a baby stay :-) td From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com]On Behalf Of ai… [at] aol.com Sent: Thursday, September 20, 2007 10:02 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Re: Cal31 Back stay I think maybe a clarification of terms may be needed here for some, including me. Any mast can "RAKE" right? Straight up, a little aft, or a little forward, but it is done with the standing rigging. Mast "BEND" is, as it states, bending the mast in the middle to flatten the main, (and tighten the forestay)right? So, with a tree trunk mast, when you adjust the backstay all you are doing is raking the mast back a bit as to tighten the headstay, Right? So if your forward lowers are too tight you are either putting way too much load on the system or not getting much rake, Right? A thinner bendier mast gives you more options, but it is up to the sailmaker to achieve the proper design for the different masts, Right? Daniel Casey "AirTime" Cal 9.2R #75 Santa Barbara _____ See what's new at AOL.com <http://www.aol.com?NCID=AOLCMP00300000001170> and Make AOL Your <http://www.aol.com/mksplash.adp?NCID=AOLCMP00300000001169> Homepage. DISCLAIMER: Important Notice ************************************************* This e-mail may contain information that is confidential, privileged or otherwise protected from disclosure. If you are not an intended recipient of this e-mail, do not duplicate or redistribute it by any means. Please delete it and any attachments and notify the sender that you have received it in error. Unintended recipients are prohibited from taking action on the basis of information in this e-mail.E-mail messages may contain computer viruses or other defects, may not be accurately replicated on other systems, or may be intercepted, deleted or interfered with without the knowledge of the sender or the intended recipient. If you are not comfortable with the risks associated with e-mail messages, you may decide not to use e-mail to communicate with IPC. IPC reserves the right, to the extent and under circumstances permitted by applicable law, to retain, monitor and intercept e-mail messages to and from its systems.

I would agree with all that. In my case I have the mast 'raked" maximally by having the forestay as long as possible. This helps upwind performance.You can measure the rake by dangleing the main halyard and seeing how far back from the mast it sits. I also use my forward lowers to pull the misection of the mast forward and create bend. This flattens the main and I feel makes the boat less tender. When I had a new main built I had the sailmaker build it somewhat flat and this has made huge improvements in boatspeed, although the original main was very ugly/deep and bagged out. Frank ----- Original Message ----- From: ai… [at] aol.com To: Ca… [at] yahoogroups.com Sent: Thursday, September 20, 2007 10:01 PM Subject: Re: [Cal_Boats] Re: Cal31 Back stay I think maybe a clarification of terms may be needed here for some, including me. Any mast can "RAKE" right? Straight up, a little aft, or a little forward, but it is done with the standing rigging. Mast "BEND" is, as it states, bending the mast in the middle to flatten the main, (and tighten the forestay)right? So, with a tree trunk mast, when you adjust the backstay all you are doing is raking the mast back a bit as to tighten the headstay, Right? So if your forward lowers are too tight you are either putting way too much load on the system or not getting much rake, Right? A thinner bendier mast gives you more options, but it is up to the sailmaker to achieve the proper design for the different masts, Right? Daniel Casey "AirTime" Cal 9.2R #75 Santa Barbara ------------------------------------------------------------------------------ See what's new at AOL.com and Make AOL Your Homepage.