Re: [CR] Brakes and flex


Example: Component Manufacturers:Cinelli

In-Reply-To: <4D242ADA.9060403@m-gineering.nl>
References: <D27D31E1-60E1-4C2F-BDBD-FCCD546DDD7B@att.net>
Date: Wed, 5 Jan 2011 06:16:48 -0500
From: Ken Freeman <kenfreeman096@gmail.com>
To: M-gineering <info@m-gineering.nl>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR] Brakes and flex


Are we speaking about elastic stressing of the cable or inelastic? Elastic stretching would cause a "spongy" feeling, where inelastic would feel spongy until the length began to change permanently. After this point one would have to adjust the cable slack.

If we're talking about housing compression or taking up the cable play inherent in a loosely-fitting housing, inelastic stress cycling is pretty unlikely, in my thought experiment.

On Wed, Jan 5, 2011 at 3:24 AM, M-gineering <info@m-gineering.nl> wrote:
> On 1/5/2011 6:58 AM, Jon Spangler wrote:
>
>
>> John Betamus, thank you for making me not feel alone in the world of
>> bicycle
>> mechanics with regard to cables not stretching. I'm always shagrined (not
>> crestfallen) when I hear someone who says their mechanic said this or that
>> about cable stretch. I think of it this way: If you try to hang a car from
>> a
>> bridge with a bicycle cable, it will stretch...and then break. But the
>> forces we put on these cables are not stretching them.
>>
>>
>
> Sorry, but you are stressing and stretching the cables with braking forces,
> only not very much otherwise they wouldn't last at all.
> It is steel, so if you apply force to it it deforms, period
>
> But in the total of armflex, squirm and compression of the blocks and cable
> it is not the most significant. Still stretching the rear brake cable by a
> millimeter shouldn't be beyond most of us, provided the other bits in the
> system are stiff enough to allow it.
>
> --
> mvg
>
> Marten Gerritsen
> Kiel Windeweer
> Netherlands