Nacra "race package" trapeze marstrom-like double block / hoop supplier wanted

those look like stock setups for racing (no height adjuster, just a thimble, with a trap stopper on the line.
available everywhere boat parts are sold (wire, t-handle, thimble - plastic stopper)

same as this except without the "cant miss" handle, and the small block under the thimble.
http://www.murrays.com/mm5/merchant.mvc?Screen=PROD&Product_Code=01-1120&Category_Code=C-TRA&Store_Code=MS

Edited by MN3 on Jul 22, 2013 - 10:55 AM.

I think you may be looking a couple pages lower at the non racing package setup. I mean this:

This is like the marstrom hoop and double block (I think nacra might actually source it from them)

Does anyone know a dealer with access to these parts? Thanks,

Dave

Finally tracked them down at surfcitycatamaran.com (nacra dealer)

Jericho,

Did surfcity also have the dogbones in-stock? I'm torn between those and a few of the murray's styles. Which fail less? I'm done with the wire rings, seen those fail a number of times.

Thanks,
Sam

samc99us wrote: Which fail less?

Stay away from the can't miss/can't hurt wire rings. I'd bet those are the ones you have heard about failing.
The problem is that they can (and do) rust in places you can't see, and then part in a surprising and wet way.
The stainless steel welded dog bones rarely fail, and are easily inspected.

We decided to use aluminum rapelling rings, http://www.ems.com/product/index.jsp?productId=3657274

The price is unbeatable and the reliability extremely high.

Also, for those looking for the double blocks seen in these photos you might want to thing twice. I received a quote at $54 EACH. You need 4x. I decided to use antal-type rings instead (giving the new Ronstan shock blocks a try), at $15/pair this by far the least expensive solution. One still has to tie the two blocks together but that is easily done with a Spectra loop, again inexpensive. My only concern is friction, but I peg the failure rate of this system at easily 10% of the failure rate of any other option. Plus for less than $200 I get a completely brand new adjustable trapeze setup on all 4 wires, top to bottom including new 7/64" dyneema trap lines.

would love to see a picture of your rigged system when ready - and a post use report

Would be cool to find a new / cheaper way ... my gear is way past due for replacement.

samc99us wrote: I received a quote at $54 EACH.

Try these:
http://nautos-usa.com
search for 92440 $11.90 each
5|16" line max, for trap most use 3/16" dacron or smaller synthetic

This company has been making SS hardware for the aerospace industry for decades, recently moving into sailing.
I have used some of their blocks on my cat for a couple of years without any problems.
Their quality = Ronstan, IMHO, except I have heard cautions about the roller furler swivels not handling beach cat loads well.
No personal experience there, though.

Wow, that's a fair bit cheaper. Then I checked the working loads. 260 lbs. In my case that is insufficient. I am applying 360 lbs of load to this block in a 2:1 configuration. Might be OK for the less serious sailor who can afford a failure.

We're racing this boat offshore, and the "name brand" blocks are known to fail. Hence the reason for the antal ring method, those have a MUCH lower failure rate. Having a block fail offshore with 30 frenchmen bearing down on you...yeah not for me.

Edited by samc99us on Aug 08, 2013 - 02:29 PM.

i assume you are saying you weight 180 - that is a static value (you sitting still)

that value is probably double or tripped when you launch your cat over a wave top and your cat bows dip down into the second wave

I am applying 360 lbs of load to this block in a 2:1

Good point on the static vs. loaded value. For what it's worth, the Ronstan double block has a MWL of 550#'s and a breaking load of 1210#'s, almost double the shock blocks. But still, the shock blocks are aluminum so you can see failure. Done "right" you might consider Antal rings, http://www.apsltd.com/c-583-low-friction-rings-and-blocks.aspx, but the cheapest of those are $12 each and more importantly the splicing is tougher than what my plan is for the shock block.

I'll post photos when I'm done, and detailed line lengths. Trying to take better notes.

Edited by samc99us on Aug 09, 2013 - 10:11 AM.

Had others suggest another option for the solid ring is google FRX rings for vendors and sizing.

I researched the blocks before sourcing the Marstrom ones and a number of people have noted the ronstan double blocks blowing out, I would not trust the nautos either for trap setups they look very similar and similar loading specs which don't appear sufficient for that application.

The setup recommended by some sailors in the PNW (thanks for the tip Chris!) was just the ring and the opposing forces pull the lines clear without contention apparently so it does the job of the double block.

For the question on the dogbones they seemed to have all the parts in that Marstrom (Nacra) kit; not sure the quantity on hand but those look to be standard on cirrus 4 and infusion mkII now. I like that the dogbones have no plastic cover which hides any potential failure stress until its too late.

For handles, I like this style and they make the donuts in red and green so you can use one color for skipper and the other for crew. This Macca video talks a bit about the advantages of a donut style handle vs a grip for wire to wire http://www.youtube.com/watch?v=O_U9cjQRoso

Dave

Sam- Wanted to check in to see how you like your setup now that you have a decent amount of usage. Anything you'd do differently? Adjustable traps are on the docket for me this spring.