Originally Posted by
p2templin
What I don't think has been mentioned on this thread yet is that the electronic shifters auto-trim the front to align with the rear FOR EVERY GEAR. That's not possible on an indexed mechanical system: my DA double has three or four indexes, my Tiagra triple I think has five indexes, and our Campy Chorus/Mirage quad has maybe twelve. The electronic ones have 20.
I've told our tandem dealer to order us an electronic group as soon as it's available in a triple. (I'll go from quad to triple to get electronic shifting, but I'm not willing to go from quad to double.)
The SunTour Cyclone Symettric shifters of the '80's would trim the front derailleur to match the rear derailleur's position via a cam in the shifter body:
http://www.velobase.com/ViewComponen...0-06DAA7456995
This system actually worked, but it was superseded by index shifting and then "integrated" shifting by the '90's.
A while back I test-rode a Di2 bike at the Shimano booth at a show (Handmade Bike Show? I can't remember.) The rear worked fine, the front jammed repeatedly even though I had a Shimano tech standing next to me. Don't know what was wrong, but as soon as I got off, they took the bike off the stand and hid it behind a curtain.