Re: [CR]small-small and big-big combos


From: "Raoul Delmare" <Raoul.L.Delmare@worldnet.att.net>
To: <classicrendezvous@bikelist.org>
References: <CATFOODucyHATWTUizO000017c1@catfood.nt.phred.org>
Subject: Re: [CR]small-small and big-big combos
Date: Tue, 2 Sep 2003 09:33:14 -0500


Hey Thanks Steven ,

Somehow I'd failed to look at it that way . Explains it very well . Chain stiffness !

And it certainly helps explain why the first cable-operated derailleurs were for :

3-speeds with 1/8 chain

4-speeds with 3/32 chain

I've always winced at the thought of trying to put very much side to side deflection on a 1955 1/8 inch chain !

Raoul Delmare
Marysville Kansas


----- Original Message -----
From:
Cc:
Sent: Tuesday, September 02, 2003 9:19 AM
Subject: Re: [CR]small-small and big-big combos



> Marcus wrote:
>
> > I know most of the literature says don't use the small-small or big-big
> > combinations. Doesn't this generally refer to triples and/or modern bikes
> > with wider spacing? I would think that on bikes in the CR timeframe, with
> > double chainrings, cross-chaining would not be as big of an issue, unless
> > the chainstays were really short.
>
> Actually the crossing on older bikes was far more problematic than with new
> bikes. Modern chains are now so flexible that most can handle quite severe
> sideways bending, something that was definitely not possible in the classical
> era. As the chains didn't flex, this meant extreme pressure on the teeth of
> both chainrings and freewheel. Friction derailleurs on the other hand do make
> keeping derailleurs in check with extreme angles easier.
>
> Steven Maasland
> Moorestown, NJ