Re: [CR]Are vertical dropouts made backwards?

(Example: Framebuilders:Tubing)

Date: Fri, 15 Aug 2003 17:05:04 -0700
From: "Chuck Schmidt" <chuckschmidt@earthlink.net>
To: classicrendezvous@bikelist.org
Subject: Re: [CR]Are vertical dropouts made backwards?
References: <200308152342.QAA18661@cascade.cs.ubc.ca>


Donald Gillies wrote:
>
> Jobst Brandt once wrote:
>
> > The longitudinal dropout also was a major cause of Campagnolo axle
> > failures because the jam nut is unsupported in the fore and aft or chain
> > tension direction. Chain tension is about a four times greater force
> > than rider weight because it has about a 2:1 ratio at the crank and is
> > concentrated on one side of the axle. Those dropouts bugged me from the
> > first day I worked with them. I was glad to discover vertical dropouts
> > on Diamant bicycles at the 1960 Olympics. That was the end of axle
> > adjusting screws for me."
>
> Don't be silly, jobst. The jam nut could be supported on a 3rd side
> (instead of just topside and downside) by threading the dropout
> adjuster head through a metal shim. It just isn't done. You could
> also reverse the adjuster and have the wheel exit the dropout in the
> rear of the bike, like a track rear fork, allowing the jam nut and
> axle to be supported by a horizontal dropout. In fact, if you had the
> dropout adjuster on the front (right bike side), and the back (left
> back size), then i bet you could ride without tightening the quick
> releases or axle bolts.
>
> It seems that horizontal dropouts aren't the problems; its the
> _design_ of today's horizontal dropouts that are a problem.
>
> - Don Gillies
> San Diego, CA

Don, Jobst Brandt isn't on this list. You should contact him <jobst.brandt@stanfordalumni.org> if you want to debate his point. And today's dropouts are not horizontal; today's dropouts are vertical. And off topic, but you knew that...

Chuck Schmidt South Pasadena, CA

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