Originally Posted by
Cougrrcj
The position of the rear axle to the rear derailleur pivot is crucial to precise shifting. It is all about shifting geometry. A millimeter or two in alignment makes for that elusive 'buttery-smooth' shifting (we're talking friction shifting here!)
I learned something new. I'll pay more attention on my friction shifting bikes. In looking this up, I found this old
BF thread where none other than Sheldon Brown weighed in.