backstay adjuster

[chris1f]

Can anyone give me some advice on choosing a backstay adjuster for my Cal 28-2? I need it mainly for club racing, and have narrowed the choice down to a mechanical adjuster ( wheel type? fold out handles type?), or a block and tackle system (anyone have an idea of the best configuaration? likely cost?). Any help would be appreciated.

A block and tackle or split backstay is probably the way to go as adjustments can be made more quickly and has easier visual indicators for quick reference. Depending on the set up they should be cheaper than a turnbuckle with an adjsutment wheel.

Jeff

[chris1f]

Thanks for your reply. Yeah, block and tackle is the way to go. Do you have any recommendations for the type of configuration? Right now, I don''t have a split backstay, but I guess I can get a rigger to put one on. Is a split stay essential, or can you stick with a single stay? I''m open to all possibilities but would like to keep the cost down.

Thanks a lot.

[geohan]

It may be possible to adapt a lever type boom vang and get by with the single backstay and chain plate. Assuming a masthead rig I would avoid any block and tackle rig that wasn''t fail-safe. The simplest rig would be a stout lever with its end shackled to the chain plate and the backstay fitting attached to the lever a few inches toward the other end. The "other end" would carry a three or four part tackle to a cleat on the stern quarter. You would have to work out the mechanical advantage needed. And it is IMPORTANT to make sure the total geometry didn''t allow unfair strains on the chain plate or any of the backstay fittings through out the entire possible range of lever movement. This is offered as a concept only. The engineering needed is up to you.

[paulk]

We use a block and tackle with a split backstay on our J/36. The 4:1 tackle pulls a pair of sheaves down the two split backstays, pulling them together to tighten them and bend the mast back. The power in this type of setup depends upon how high up the split starts. When it''s not needed, the tackle can be unrigged to allow passage through the spit backstay - very convenient for the transom ladder. It also doesn''t leak hydraulic fluid, and even if the adjuster were to break (not likely), the stay(s) would still be there to keep the mast up.

I would suggest that you avoid the lever setup. You typically don''t have the range of adjustment that a backstay adjuster needs and the custom fabrication of a lever able to withstand backstay forces would be quite expensive.

Probably the easiest set-up for a boat without a split backstay would be a cascading set up where you have a single wire block hung on the end of the backstay. (The backstay will need to be shortened.) A wirerope then runs from a trianglar plate at the chainplate at the deck thru the block on the backstay. Depending on the size of the boat there would typically be another wire block hung on the end of the first wire rope and another wire rope that runs through that block and has a thimble in the end. Again depending on the size of boat there would typcially be a 4:1 up to a 6:1 purchase. This combo results in a 16:1 to 24:1 overall purchase. (On really big boats there may actually be a third cascade resulting in 32:1 to 48:1 purchase, but for example, my prior boat, a Laser 28, had a 16:1 and my Farr 38 has 20:1 purchase on their backstay adjusters which seem adequate.)

Garhauerer seems to have the best prices on the kind of low friction blocks that you are looking for.

Good luck,
Jeff

[smoke]

Are you sure you don''t want to try one of these? I''ve tried all the other versions you''re considering. Believe me, the extra cost for a good Sailtec or Navtec is worth it. Looks neater, works better.

http://www.pyacht.net/cgi-local/SoftCart.exe/cgi-bin/pagegen.pl?U+scstore+xmts1056ff3ba63b+pr+sailt10SI .html

[chris1f]

Our local rigger also recommended a hydralic system, but at $1000 bucks installed, it seemed too expensive. I''m sure you''re right about the money, but I was trying to do this with about $350 or less.

Thanks,

Chris Foley
Cal 28-2
Morning Star

The real problem with hydraulics on a small boat, besides maintenance, is that they are hard to put on and off quickly. With a block and tackle system it is very quick to make repetitive adjustements.

Jeff

[geohan]

I guess that I would have to admit that a lever type backstay adjuster ins''t for everyone. I wouldn''t want to pay shop rates to have one built. I do insist however that a handy do-it-yourselfer could fabricate such a device that is capable, convenient, aesthetic and economical. Capability is foremost and you can get that for $15. Convenience and aesthetics are extra, a lot extra.
Cheers, George