Re: [CR]Are vertical dropouts made backwards? - Teledyne Titan failures?

(Example: Framebuilders:Pino Morroni)

From: "Steve Neago" <questor@cinci.rr.com>
To: "Donald Gillies" <gillies@cs.ubc.ca>
References: <200308152342.QAA18661@cascade.cs.ubc.ca>
Subject: Re: [CR]Are vertical dropouts made backwards? - Teledyne Titan failures?
Date: Fri, 15 Aug 2003 20:52:41 -0400
cc: classicrendezvous@bikelist.org

Hmmm...

I wonder if this is part of the reason why Teledyne Titan frames frequently break the rear derailleur hanger or vertical dropout... too thin a metal reinforcement dropout and a mis-calculation of drive force that causes pre-mature metal fatigue?

Thanks, for the explanation!

Regards, Steve Neago
Cincinnati, OH


----- Original Message -----
From: Donald Gillies
To: classicrendezvous@bikelist.org
Sent: Friday, August 15, 2003 7:42 PM
Subject: [CR]Are vertical dropouts made backwards?



> 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