Dan Kasha wrote:
>
(cut)
> 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.
Not a myth in my experience.
I do think that the lower chain run causing autoshifting is not a possibility; just my opinion though.
I will say I have been able to solve any autoshifting problems I have ever had with Simplex and Campagnolo DT shifters to my satisfaction.
Chuck Schmidt L.A.
.