Originally Posted by
wrk101
On one bike right now, I can get it to shift up to the big ring, but not back down to the small ring. On another (RSX), I am getting three solid shifts (triple), but on the big ring, either I get a lot of rub, or it just doesn't make it. On the RSX bike, I just had the shifters rebuilt, so they are good. And when I am 0/5, I suspect mechanic (me) error.
On the first bike, the cable is pulling the cage too tight against the high limit screw. Let out a little cable tension or let out the limit screw and re-calibrate. On shifting to the big ring, the cage should lightly kiss the limit screw as the shifter ratchets into the outer position.
On the second bike it sounds like you need to let out the high limit screw a bit--try this and try a few shifts by yanking on the derailleur cable. If it works, add a little tension to the cable and fine-tune limit screw and cable tension.
By the way, both Park Tools and Shimano have web pages on derailleur setup and tuning.