Re: [CR] Brakes and flex


Example: Framebuilders:Alberto Masi

In-Reply-To: <4D245F65020000FE000170DD@inetgw.co.ba.md.us>
References: <4D245F65020000FE000170DD@inetgw.co.ba.md.us>
Date: Wed, 5 Jan 2011 18:48:47 +0000
From: Harry Travis <travis.harry@gmail.com>
To: Daniel Artley <dartley@baltimorecountymd.gov>
Cc: Classic Rendezvous <classicrendezvous@bikelist.org>
Subject: Re: [CR] Brakes and flex


What matters is settled or transient deformation or re-alignment anywhere in the Bowden cable system. Mention braided cable and I instantly see "stretching" right in the cable itself, as with braided rope. Of course, the strands take straighter path under load.

Spokes have been mentioned We all know that spokes elastically stretch. One reason for thinner and double-butted spokes is to take advantage of that elastic stretch for shock-softening and broadening and comfort.

But, back to un-braided, straight brake cable: Please, has someone clamped a length of it in a vice, applied static or transient loads on it, and measured the maximum "stretch" of various kinds, to failure? Am I really strong enough, with a brake lever, to stretch the cable?

I'd like to know that I'm right or wrong in belief that other parts of the braking system are responsible for the overwhelming part of "softness" in the bicycle braking system, that cable "stretch" is trivial compared to other deformation.

Perception of stretch isn't made easier by sale of cable labeled as "pre-stretched."

Harry Travis Pine Barrens of NJ USA

On Wed, Jan 5, 2011 at 5:09 PM, Daniel Artley <dartley@baltimorecountymd.gov
> wrote:
> Back in the seventies/eighties I preferred the braided wire brake cables
> over the stiffer Campagnolo cables. The Campy cables combined with their
> sidepulls were so stiff that if you ran over a small pebble or rock while
> braking the tire would 'skip' for a little jump. The braided wires soaked
> up those little skips and still seemed to brake as well. The modern pressed
> stainless seems a great compromise and works so well with plastic lined
> housing and Triflow juiced through. Just my opinion.
>
> Happy trails,
>
> Dan Artley in Parkton, Maryland