An excellent discussion....

[Alan]

...on the merits of backstay tension for both frac and masthead rigged boats. The March '07 issue of Sail Magazine has an excellent article on backstay adjusters and how they can be used by both frac and masthead rigged boats to great advantage for both cruising and racing sailors. The article in the "Know How" section under Backstay Tensioner on page 98 does a good job of debunking and demystifying this little used control.A very informative read.

 

[Don Guillette]

Readers Digest Version

Alan: Could you give the Readers Digest version of what they said about the backstay adjuster as it applies to a fractional and masthead boat? I've always felt the backstay adjuster was next to useless with "telephone pole" type masts that are on most production boats. You can use it to tighten the forestay but that makes for other problems that are beyond the beginner to high intermediate sailor. Do they mention anything about the problem of raking the mast such as an increaase in weather helm?I'm always looking to learn something new.

 

[Alan]

The Readers Digest version,

Modern sails are assembled that are light years ahead of what was available 25 years ago making them very adaptable to wind speed and direction. Proper halyard tension and sheeting angles can yield pointing higher and going faster. Failure to make the needed adjustments will prevent you from benefiting from these technologies.Often overlooked is headstay tension, the first step to proper trim. That gentle curve in light air is just what is needed but as the wind builds this curve costs speed and pointing pointing.On a frac rig when the backstay is applied only 50% of it is translated into headstay tension whereas on a masthead it all is. But todays masts are engineered to transfer headstay tension with minimal bend resulting in greater headstay tension. Furlers also require a straight foil for ease of furling and reduced wear.The rest of the article goes on to discuss the various backstay adjusters that are available and their significant merits.As with all boats there is a trade off for some things in favor of others. True a tensioned backstay increases mast rake but it also depowers the genoa and main at the same time. The gain in weather helm is offset by the reduced heel and lowering the traveler. IMHO the pluses in backstay adjusters far outweigh any minuses.

 

[John Nantz]

Additional Mast Rake?

So, Don, how much additional mast rake does additional backstay tension add?

 

[Alan]

So Don

Are you saying that you disagree with having and using an adjustable backstay?

 

[John Nantz]

Backstay adjustment adds SMALL amount of rake

When the C30 guy said he added 5" of adjustment I'm sure he meant he brought in the backstay 5" and not that he raked the mast back by that amount. I don't know this for a fact because I wasn't there but unless he had a really, really loose rig ..... well, 5 inches of horizontal movement at the masthead on a C30 is a lot. Also, I don't know if this is the maximum adjustment from very loose or if it was somewhere in between, like going from a beat in light wind to heavy wind or if it was from a downwind run to a beat in heavy wind.In any event, if the 5 inches was taken out of the backstay to remove headstay sag then the amount of mast movement aft-ward will probably be of the order of, say, maybe - around one inch to a max of maybe two inches or so but it depends on the starting point - how loose things were to start with. I don't know what the standard rake for a C30 is but for my H35 it's of the order of 6 to 8 inches. I don't have my manual handy or I could look it up so this figure is a combination of shooting from the hip combined with faint memory. As a percentage of normal rake, the 5-inches backstay adjustment does not contribute a tremendous amount to the overall rake. The horizontal movement of the mast to reduce headstay sag is comparatively small. And, when tuning the rig it would be prudent to optimize it for the conditions one sales in, or in the case of the Nationals, the conditions one anticipates, and factor in the backstay adjustment range needed. Speaking of C30s, I don't know if it's been corrected in the newer production boats, but the earlier C30 apparently had a problem with the sail plan and helm. I don't know what the details were but many C30s have added short, stubby bowsprits. There may have been an element involved here as rules may have prevented the participants in the Nationals from having bowsprits.If the skipper you were talking about had severe weather helm I'd say it wasn't due to too much backstay tension, because this is factored into the rig tuning, it was do to any one of many other possibilities, starting with incorrectly tuned rig, to begin with, and going on from there. Sails with too much draft, like old sails, are a really big factor in weather helm.As far as I'm concerned, the ability to reduce headstay sag is vitally important to good performance, and especially upwind, and a backstay adjuster is one of my favorite tools. There's not much that is more satisfying in sailing than pointing higher and, while at the same time, sailing faster than the competition.

 

[Stu Jackson]

Short stubby bowsprits on C30s

John, it is my understanding that these were added to tall rig models (only???). May be an urban myth...I agree with you that the telephone pole masts on Catalinas really don't move much at all, and reducing headstay tension is the reason for backstay adjusters for these masthead sloops.

 

[John Nantz]

Puget Sound C30 'sprits

Thanks for the feedback Stu. In our area it seems that quite a few C30s are sporting short bowsprits. This could be to increase some sail area or something else. If the rig came in a standard and tall version, for Puget Sound, I would think the tall rig version would be the one that would be the most popular. The weather gods seem to like mostly ON or OFF, with not a whole lot in between, and with the majority of the winds in the nearly off mode, hence the tall rig popularity. When it blows, though, it really blows.In the case of the little bowsprits, at least a couple of them that I know of were owner-installed, so for our urban area, at least, they're fairly popular. And so is the C30 for that matter.I'd imagine that on the Bay you guys would be using the backstay adjuster quite a lot.

 

[Jon W.]

Backstay adjuster on C310

I'll have to look for that Sail Magazine article. I've got it around here somewhere. Just a couple of my observations. I think the C310 rig (double spreaders) is a little different than the C30, but is essentialy the same. I only use my backstay adjuster to control headstay sag. I like to keep things really loose in winds below 10 knts, to try and add some extra power to the headsail. I also like the backstay sloppy loose in really light air to make it easier to pop the full length battan through while tacking or jibing, going so far as shaking the backstay by hand.When the wind picks up, I crank it down hard. Measured at the dock, the full on adjuster moves the masthead aft by 1 to 1 1/2 inches. This seems to coincide with what John Nantz was describing. Very little mast bend is induced, mostly in the upper half. I don't think it does much of anything to depower the mainsail. I don't think there is any overall increase in weather helm either.