Originally Posted by
jolly_codger
No danger of slack because setting it up you click the lever once before the cable is installed. That plus the low stop not allowing the front mech to go further in precludes cable slack; you can click the last release click does but it does nothing but click. Anyway, just another way to approach the task and most importantly, it shows that a 3x shifter will absolutely work with a 2x crankset.
If you start on position 2, how are you not going to have cable slack if you shift to position 1? The brifter is spring loaded - it will push the extra slack out of the shifter even if the FD isn't pulling.