Originally Posted by FrankJohns
This is from Park Tools. I mean...it's a cable pulling a spring...
"Modern indexing shift levers use dwell, which is a hesitation between movements in the lever. These hesitations are timed to match the movements of the derailleur and the spacing in the rear sprockets. The design of some derailleur and shift lever brands requires more of a push (or twist) of the lever to complete the shift. The amount of extra push or twist is not consistent between manufacturers and each rider must learn the particular attributes of his or her system."
right, but one click should always equal one shift. you shouldn't have to overshift in the rear at any point. the front is always going to have a little discrepancy between when the shifter clicks and when the chain actually shifts. but the rear, if properly adjusted, regardless of which system you're using, should shift right on the click. and it should be consistent across the full range of the shifter within the same system. not 1 click here, then 1 1/4 click there, then 1 1/8 click in another place...a properly adjusted rear derailleur will shift at the same point in blah blah blah blah.....