Re: [CR] Brakes and flex


Example: Component Manufacturers:Avocet
In-Reply-To: <1AF44DEDBB574D42885E6BF8375640B8@gateway2v8e13w>
References: <1AF44DEDBB574D42885E6BF8375640B8@gateway2v8e13w>
Date: Tue, 4 Jan 2011 20:53:53 +0000
From: "Harry Travis" <travis.harry@gmail.com>
To: Charles Nighbor <cnighbor1@comcast.net>
Cc: classicrendezvous@bikelist.org
Subject: Re: [CR] Brakes and flex


Engineer Jobst Brandt has written in rec.tech and maybe elsewhere about, iirc, "cosine error" characteristic of all double pivot brakes, and still uses, seriously, as in Alpine tours, single pivot Campag Record or Super Record.

My uninformed belief is that we've never seen measurements or images clearly pointing to where the "give" is in the bicycle braking system, so it is mostly attributed to the wrong parts.

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.

Or, maybe I have it completely wrong, and the greater adhesion of contemporary brake pads puts previously rare loads on contemporary brake calipers. And maybe Thor Hushovd squeezes brake levers with as much astonishing peak load as he sprints with and there are many more his equal riding as punters.

Harry Travis Pine Barrens of NJ USA

On Tue, Jan 4, 2011 at 7:27 PM, Charles Nighbor <cnighbor1@comcast.net>wrote:
> I use Campanolo Record 70's and early 80's, 1st generation brakes and
> notice no brake flex when slowing down fast coming down Mt. Diablo at 30
> mph. Some of the older Mafac and Universal I did notice brake flex. Since
> discarded. Modern brakes like Dura-Ace and Campagnolo Record have gotten
> stronger looking in appearance but if I didn't notice and flex in on period
> brakes why the big change in brake design. And I wouldn't mention those CADD
> machined brakes.
> Is it that in racing you need every bit of stopping power you can get with
> no flex. Or is just an evolution in bicycle components.
>
> Thanks
> Charles Nighbor Architect
> Walnut Creek, CA USA