Originally Posted by
FBinNY
The only other possible source of friction within the lever (that I can think of at the moment) is if you omitted the small washer that fills the recess in the back (bottom) of the cam, and the rim is riding on the balls of the bearing below rather than on the inner race.
Test for friction by using an allen key in the screw. It should rock back and forth with something approaching zero torque.
I just mount the shifter at the end of the bar, so I can see the mechanism during shifts. It seems that the g-spring carrier always returns to the correct position after a shift. When I push the thumb paddle to trim (which silences the noise after downshift), it seems like two things might have happened:
(a) The entire carrier-ratchet assembly is moving in the lever body slightly, as there is some gap between the body and the g-spring carrier.
(b) The ratchet mechanism (part 6) seems to move relative to the carrier (part 9).
If observation (a) is important, the shifter is probably a lost cause. Perhaps the lever body is out of tolerance, therefore, the carrier-ratchet mechanism can rock in the body.
If observation (b) is important, there are mainly three interfaces between the ratchet and carrier:
(i) g-springs. But these are brand new.
(ii) Coil spring. I just replaced it this morning (LBS happens to have one in stock), and I am pretty sure it is wound correctly.
(iii) The bushing between the carrier and ratchet (part 19).
Item (iii) is actually kind of suspicious to me. According to Branfordbike.com (where I purchased an aluminum carrier and g-springs), there is actually a bushing specific to the aluminum carrier. I missed to order it last week, and just used the bushing specific to the carbon carrier when I put everything together. It's a long shot, as I doubt it makes that much difference in friction between the carrier and ratchet.