[CR]Re: Autoshifting DT levers

(Example: Framebuilders:Tony Beek)

From: "Dan Kasha" <kasha.lists@cox.net>
To: <classicrendezvous@bikelist.org>
Date: Fri, 30 May 2003 07:43:05 -0400
Subject: [CR]Re: Autoshifting DT levers

I am going to highly question what Chuck states here (sorry Chuck).
>DT levers slipping is also a component of how stiff your frame is
>laterally. Flexy frame = autoshifting.
>Chuck Schmidt
>L.A.

As an example, I recently put NR shift levers and rear derailleur on my cannondale and the auto shift is the worst I have yet experienced, but due to the friction of the dt shifter, and not the frame flex. How do I know? Well first off, it is not a particularly flexy bike. Secondly, I also ran the same derailleur (and even cable) with a shimano 105 non/indexed shifter and there was absolutely no autoshifting ever, period. (by the way, those 105's are amazing little cheap levers). If it was frame flex, and not shifter slip, then why would it change when I change shift levers?

What I do think causes the autoshift is the return portion of the chain oscillating left and right as you climb and rock the bike. There is a decent amount of weight of chain that is not under much tension down there. When you rock the bike left and right while climbing, that chain puts lateral force on the derailleur's cage and if you don't have enough friction in your levers, you are going to get autoshift.

Give it some thought. Do some experiments. I think you too will decide that the frame flex thing is at least partially (though I claim fully) a myth.

Dan Kasha
Providence, RI, but moving to
Salt Lake City, UT in 20 days!