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#249728 - 06/18/12 12:28 AM Nacra 5.0 Rudder Bungee System question
dannno Offline

Registered: 06/04/03
Posts: 14
Hi all -

I have an older Nacra 5.0 with the older rudder system that uses bungee to pull the blades up when the blades are released.

I've tried all different types and diameter of bungee and cannot find one that works. If the bungee is too stretchy, the blades don't pop up when released. If the bungee is not stretchy enough, the bungee is too taught to pull the blades down while sailing.

I thought I remember someone suggesting running two bungees on each blade, that didn't work either.

Anyone have any suggestions on bunggee material to use or another solution short of changing to the newer rudder system?

#249729 - 06/18/12 12:53 AM Re: Nacra 5.0 Rudder Bungee System question [Re: dannno]
goose151 Offline

Registered: 07/19/11
Posts: 9
8mm shock cord. The total length is 125% of the length of the rudder arm. ie if your arm is 710mm long you need 710*1.25= 900mm. This allows for a 45mm over lap (join).

#249732 - 06/18/12 04:19 AM Re: Nacra 5.0 Rudder Bungee System question [Re: dannno]
erice Offline
old hand

Registered: 09/13/07
Posts: 757
Loc: japan
many off us only rely on the bungee as an emergency popup to save the transoms from being ripped out

to get an early nacra rudder all the way up and locked means fitting another jam cleat on each alloy tube and a line running from the back of the rudder, up through a split ring on the tube end and through the jam cleat
eric e
1982 nacra 5.2 - 2158
2009 weta tri - 294

#249739 - 06/18/12 09:21 AM Re: Nacra 5.0 Rudder Bungee System question [Re: dannno]
JeffS Offline

Registered: 05/25/06
Posts: 1308
Loc: Kingston SE South Australia
Do what goose said, the only thing I can add is the brand of shockcord is important. Most shockcords sag very quickly not holding the rudder up but the brand that Nacra sells doesn't stretch and sag after you set it. Nacra sells it cut to length and it's very cheap. If you cant get proper shockcord you can make 10mm fit through the hole in the blade with a bit of effort then pull each end out the end of your tiller arm then tie a knot in one end then stretch the other out as hard as you can and tie a knot in it. The knots won't fit down the tiller arm. Definately not as pretty as doing it with the Nacra shock cord. To do it perfectly with the 8mm shockcord Nacra have stainless steel clips that you can apply with pliers that lock the bungy together. I've done both of these methods to two different Nacra 5.8's in the last 2 weeks. If no matter how hard you tighten the shockcord the rudders don't pop all the way up unless your blades are a bit sloppy in the rudder stocks, it means the top of your rudder stocks are too close together I can give you an easy fix if you have that problem, you don't want any wobble
Jeff Southall
Nacra 5.8 1667 Ram Raider
Nacra 18 Square
Taipan 5.7 134
Mosquito 404
Arrow 1576

#249754 - 06/18/12 04:31 PM Re: Nacra 5.0 Rudder Bungee System question [Re: dannno]
catman Offline

Registered: 06/17/02
Posts: 1655
Loc: Florida Suncoast, Dunedin Caus...
I would use a pull up line instead of the shockcord. That system has problems. If your rudders kick while your sailing the last thing you want to happen is to have no rudders in the water.
Have Fun


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