How to make 4:1 Trim System on 2020 North Navigator Bar

[JimmyRyder]

Great drawing
- I already had the idea how the 4:1 goes but this drawing it will make it that much easier for me.
Where would you recommend to get the dynema for the Longer Line and what type/brand should I look for ?

Here is a drawing of original and the 4:1

[downunder]

[Herman]

Have a look at the Marlow's website. That explains all the specs but most 12 strand hollow core dyneema would do the job. If you want a covered handle just splice the core to connect to the loop, keep the cover in place with a throat whipping with sown in ends. If you go to thinnest possible line rather than covered you can put an insert into the line to improve cleatability but I would advise against this. Sail thread, whipping twine and splicing tape should be on your shopping list along with a Ronstan orbit lashing block or equivalent imho. The method with the floating pulley means that the swivel/bracket can't be pulled down to the cleat and so you will have to extend your rear leaders as required ie. Same length as front with trim all out.

Pay attention to tapering the splices so you don't get a bump that will wear prematurely. I think the colonies call dyneema amsteel and paint it blue for some reason!!!!

[meccaloha]

anybody knows how the good or bad the auto-untwist is working on the Navigator bar 2020/2021 do you have to untwist the center line by hand the whole time while your riding or does it untwist it self?

[knot_moving]

This makes the job much easier. You just need to connect a new trim line and a new line for the slider to this loop.

Slider line needs to be 4x the distance from bottom of swivel to top of cleat in the original configuration, when it is all put together. Need to add more for the loops on both ends of the slider line

Trim line needs to be 4x the distance from bottom of swivel to top of cleat in the original configuration, with extra for a loop on one end & a piece to grab after the cleat on the other end.

Extensions for steering leaders and flag-out line need to be 2x the distance.

[knot_moving]

Great drawing
- I already had the idea how the 4:1 goes but this drawing it will make it that much easier for me.
Where would you recommend to get the dynema for the Longer Line and what type/brand should I look for ?

Here is a drawing of original and the 4:1

I order mine from West Marine and have them ship it to the store for pickup. Usually takes about a week. I think you are in Atlanta - there is lots of sailboat racing up on lake Lanier, so there might be a decent local sailing supply shop that stocks it up there.

[JimmyRyder]

I know West Marine, been there few times - but as you said, there are quite a few stores around here around Atlanta metro area so I will search them a bit

When you went into the local store did they do the splicing in the store for you (or would they know/want to to that for customers) ?

I'm asking because I have no idea how to do that and prefer to have a professional doing it rather then screw something up and later on find myself in the water with some problem on this part.

Great drawing
- I already had the idea how the 4:1 goes but this drawing it will make it that much easier for me.
Where would you recommend to get the dynema for the Longer Line and what type/brand should I look for ?

Here is a drawing of original and the 4:1

I order mine from West Marine and have them ship it to the store for pickup. Usually takes about a week. I think you are in Atlanta - there is lots of sailboat racing up on lake Lanier, so there might be a decent local sailing supply shop that stocks it up there.

[Herman]

If I wanted something like that made up I would go to a sail maker or a kite repair shop. That would be prohibitively expensive to me. Why not see if you can buy a kit as spares, but still making it yourself would be way cheaper if you don’t count the cost of research.

To me it seems an easy thing to do but I have been doing this sort of stuff longer than I care to remember, Using hollow core is particularly easy in 4mm and so it is a good place to start and the tooling required is rudimentary. Study the web site I suggested get a dyneema off cut from eBay and have a play. You might surprise yourself.

It also seems a bit weird that you need this. Unless you’re advanced it seems strange that you are using kites that should need this setup or are you flying in very gusty conditions.
Yes you do need trim for big kites but I rarely use it more than 2 or 3 times a session. I have however, extended the handle length on a few bars to make it easier to pull the Depower in sudden squalls.

[knot_moving]

As a teacher used to say splicing is “straightforward but non-trivial”. If you start out with single braid 12 strand line in 4mm or5mm thickness it is pretty easy to work with. I usually use New England ropes hts-75.

Here is link to Brummell splice how to

For my first fid I just got 30” heavy duty guitar string, bent it in the middle and wrapped the 6” free ends really well around a pen to use as a T handle.

Go ahead and give it a try - buy a bit extra line and play with it. As long as you bury 40-70 times diameter, it’s almost impossible for it to go wrong

[Herman]

This is just a personal rant and not a dig at knot_moving as he has provided very good information.

Generally speaking when people show splicing they show what I think is called the McDonald Brummell splice which is useful where you don't have both ends. Imho it is very rarely needed in kiting as you generally have both ends available. An ordinary Brummell even if you have to pass a spliced loop is less torturous on the fibres than inverting and reinverting the line through itself imho. Just don't rip the line through and cause heat if you are passing a full flying length.

The McDonald is a good party piece etc. Personal rant over - please ignore!!!!

PS take a look at the infexion thread if you want to see another alternative layout for a multi part trimmer, it uses a double pulley system that can pull down block to block (shorter rear leaders required!).