Re: [Paddlewise] Rudder Cable Replacement Advice

From: Erik Sprenne <sprenne_at_netnitco.net>
Date: Fri, 1 Sep 2000 00:10:39 -0500
Without negating the comments made by Fernando and Alex......

Spectra is a trade name owned by Allied for a rope made of high modulus
polyethylene (HMPE).
see   http://tensiontech.com/papers/fiber_id/fiber_id.htm  for lots of good
information on synthetic ropes/lines.

IIRC, spectra is polyethylene (PE) that has been pre-stretched so as to be
'stronger', and as such it's strength lies in its ability to withstand
tension.  Spectra lines are used in sailing applications requiring high
strength and low stretch lines, though the Spectra may be the core of a
kernmantle line sheathed in another material.  One telling characteristic of
Spectra/HMPE is a stiffer 'hand'.  Besides the pre-stretching, producers can
also play with the molecular weight of the PE (how long the individual
molecules of the plastic are), which will also alter the properties of the
material.

I remember hearing of a comparison that some professional whitewater guides
made on the utility of rescue lines made of various types of line - while
the Spectra throw line had impressive statistics on the lab bench, in
real-life applications of setting up Z-drags to free a pinned raft, braided
nylon lines were the best overall performer.

A spectra rudder line in a tubing sheath should perform superbly, as it's a
slippery, lightweight, non-rusting, low stretch material that doesn't absorb
moisture.  Areas of concern would be UV resistance, and how to attach it
without kinking/stressing it, and thereby creating the 'weak link' point in
the system.

On the Prairie Coast,
Erik Sprenne

Fernando wrote:

> >  I prefered to use a rope called
> >SPECTRA (in Argentina). This rope is the one used for parachutes. It has
a
> >kevlar core and if it expands, I really donīt noticed it. The cords
slides
> >through a rubber tube as long as it is operationally possible.
> >
Alex wrote:
> As Fernando says, Spectra is the way to go.....
>
> It does help to run the Spectra through tubes and we use home irrigation
> tubing, about 4 mm ID. and 2 mm Spectra. It might sound thin and look thin
> but that's all you need.
>


***************************************************************************
PaddleWise Paddling Mailing List - All postings copyright the author and not
to be reproduced/forwarded outside PaddleWise without author's permission
Submissions:     PaddleWise_at_PaddleWise.net
Subscriptions:   PaddleWise-request_at_PaddleWise.net
Website:         http://www.paddlewise.net/
***************************************************************************
Received on Thu Aug 31 2000 - 22:05:33 PDT

This archive was generated by hypermail 2.4.0 : Thu Aug 21 2025 - 16:30:31 PDT