Re: [CR] Brakes and flex


Example: Production Builders:Frejus

Date: Tue, 04 Jan 2011 16:42:18 -0500
From: John Betmanis <johnb@oxford.net>
To: classicrendezvous@bikelist.org
References: <1AF44DEDBB574D42885E6BF8375640B8@gateway2v8e13w> <AANLkTimpQiQSWYRYh5k=gnt7Jhrsce27pTYKCz58jH6B@mail.gmail.com>
In-Reply-To:
Subject: Re: [CR] Brakes and flex


On 04/01/2011 3:53 PM, Harry Travis wrote:
> Please someone, show me that new design stainless steel cables stretch less
> than old-skool zinc-plated ones (any more than bicycle chains "stretch.")
> Which is to say: Show me that they measurably stretch at all, as against
> simply having the ends bed and the housings move.

Springiness or lost motion in brake cables is no more due to "stretch" than a worn-out chain is "stretched". It's the housing that's the culprit when it appears to "compress". If there is excessive clearance between the inner cable and the housing, the housing will "buckle" in a series of "S" curves before any serious tension reaches the brake caliper. Moreover, if the housing is made of round section wire rather than rectangular, the coils can also "slip" allowing more "compression". I believe the reason the better modern cables have less "stretch" is due to better design and closer tolerances.

--
John Betmanis
Woodstock, Ontario
Canada