Hydraulic to Cascading Backstay Upgrade

[Pokey]

When I purchased my 911SE this last summer, the Navtec backstay adjuster was in bad shape. It was gonna cost about $325 to rebuild the unit, assuming nothing major was busted.</SPAN>

So I replaced the greasy piston and wire backstay with a double ended, 24:1 cascade, spliced to a dynex dux backstay. The system works great. It’s much lighter, more reliable, and adjustable by the helmsman or main trimmer, from their station on either tack. Cost for the system, if you paid list for all the blocks and line would be a bit more than the cost to rebuild the Navtec unit. But who pays list? And I count the cascade as a major upgrade to the hydraulic system.
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Originally I built it with 16:1 purchase, but felt it took a little too much juice to harden up.
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The low friction ring at the top cascade is a good alternative to an expensive high-load Harken block. Although a 40-Series Garhauer block would also be an economical but heavy choice. You could also go with Garhauer for the double and triple blocks. But their small standup and cheek blocks don’t compare to the Harken carbos.
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Hope this helps others weighing the cost to rebuild their hydraulic backstay adjuster.

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[Slick470]

Well done Pokey. Thanks for the write up and including the pictures and diagram. I think that I'll seriously look into this the next time our hydraulic needs rebuilt, which at this rate will be sometime next year.

 

[Pokey]

Thanks Andy,

Just finished cascade systems for the outhaul and vang today.

I'll post some info on them when I get afew mins.

 

[Reese]

I know this is an old thread, but wondering if others have done the same. Pokey? You still out there? Still own the boat? Would you do anything different if you did it again?
Looks like one of the Seattle boats has a very similar setup:

 

[Slick470]

Pokey ended up selling his boat to someone local to his area. He was really excited about the boat and got it for a steal at an auction, but unfortunately didn't quite get the buy-in he needed from his family. It happens. There is a thread with is write-up on it here somewhere. As far as I know, the new owner hasn't shown up on these forums yet.

I have his notes from this thread saved off if I ever decide to go that route, however my hydraulic backstay adjuster is still going strong *knock on wood*.

 

[Loren Beach]

I am getting our Hydraulic BS rebuilt this month. It has been faithful for many years, but a seal is now leaking. (Not a crises, since this can happen on one after a decade or two.)

This thread does kind of beg the question of just how much "purchase " it takes to equal the 2K # that our present adjuster shows when powered up on a windy drive to weather.
Pumping the handle is petty darned easy, and of course that's the allure of the present system. That, and the ease of changing the tension quickly, like when rounding a mark.
Other than the factory multiple-block BS system on the E-33RH, does anyone have an idea of how a tackle might be rigged on a 34 footer? While I have no real reason to change, I am sorta curious. I envision a whole flock of sheaves.....

 

[Mark David]

I am getting our Hydraulic BS rebuilt this month. It has been faithful for many years, but a seal is now leaking. (Not a crises, since this can happen on one after a decade or two.)

This thread does kind of beg the question of just how much "purchase " it takes to equal the 2K # that our present adjuster shows when powered up on a windy drive to weather.
Pumping the handle is petty darned easy, and of course that's the allure of the present system. That, and the ease of changing the tension quickly, like when rounding a mark.
Other than the factory multiple-block BS system on the E-33RH, does anyone have an idea of how a tackle might be rigged on a 34 footer? While I have no real reason to change, I am sorta curious. I envision a whole flock of sheaves.....

Loren,

A couple of years ago I purchased a cascading backstay adjuster for the 32-2.

It was a similar to the one diagramed for the 911SE, except that it terminated with a fiddle / cam cleat at the original tang. It did not lead forward like the 911SE. There were 4 cascades and then the 4:1 fiddle. I don't think it would have taken much effort to get the job done

The challenge was dealing with that much spaghetti, low friction rings and fiddles all terminating at a single point. Right behind the driver.

There are a few local boats that are successfully using a similar system with lines led forward, and they love it! It just wasn't right for our application.

Hope this helps,
Mark

 

[Loren Beach]

The challenge was dealing with that much spaghetti, low friction rings and fiddles all terminating at a single point. Right behind the driver.

Thanks for a humorous mental image! That indeed is what gives me pause.

 

[G Kiba]

I am getting our Hydraulic BS rebuilt this month. It has been faithful for many years, but a seal is now leaking. (Not a crises, since this can happen on one after a decade or two.)

This thread does kind of beg the question of just how much "purchase " it takes to equal the 2K # that our present adjuster shows when powered up on a windy drive to weather.
Pumping the handle is petty darned easy, and of course that's the allure of the present system. That, and the ease of changing the tension quickly, like when rounding a mark.
Other than the factory multiple-block BS system on the E-33RH, does anyone have an idea of how a tackle might be rigged on a 34 footer? While I have no real reason to change, I am sorta curious. I envision a whole flock of sheaves.....

Loren,
I am on my third Sailtec hydraulic adjuster in 5 years.
The one that came with the boat starting leaking pressure under load (under sail) the second year in. Not sure how old that unit was but it had plenty of wear on it) The new replacement would not hold pressure sitting at the dock after 3 days (that was after a year of use). it warranty replacement is working ok but will not hold 1000 lbs for more that a week at the dock. The unit seems to work well under sail. In the back of my mind, I am considering going mechanical. I am looking at similar and larger sized race boats that have mechanical backstays. So far most I have seen are around 24, to 36:1.

 

[Mark David]

Loren,

Assuming your adjuster is a Navtek....where are you getting it serviced? Mine will pump up to pressure, but slowly (2-3 hours) looses it under load. No visible leaks.

Mark

 

[Prairie Schooner]

Loren,

Assuming your adjuster is a Navtek....where are you getting it serviced? Mine will pump up to pressure, but slowly (2-3 hours) looses it under load. No visible leaks.

Mark

Hi Mark,
Post #7 from 2022 might still be relevant:

Navtec Backstay adjuster problem Ericson 35-3

Hello All, I have a Navtec hydraulic Backstay adjuster on our 35-3 that I would like to eliminate. It leaks and does not hold pressure. I would like something simple or eliminate an adjuster all together. Wondering what the options are. Thanks David Poth Ericsson 35-3 1985

ericsonyachts.org

Also this with some Navtec info:

Navtec hydraulic backstay adjuster leaking

This last weekend I was starting preparation for spring launch and I discovered the Navtec hydraulic backstay adjuster has been leaking and lost all of it's oil over the winter. A bit surprising as the adjuster was under no pressure. It looks like the top seal has gone so I'm now looking at my...

ericsonyachts.org

Jeff